Revert "Skip WAL for new relfilenodes, under wal_level=minimal."

This reverts commit cb2fd7eac285b1b0a24eeb2b8ed4456b66c5a09f.  Per
numerous buildfarm members, it was incompatible with parallel query, and
a test case assumed LP64.  Back-patch to 9.5 (all supported versions).

Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com

doc/src/sgml/config.sgml

@@ -2171,19 +2171,16 @@ include_dir 'conf.d'
         levels.  This parameter can only be set at server start.
        </para>
        <para>
-        In <literal>minimal</literal> level, no information is logged for
+        In <literal>minimal</> level, WAL-logging of some bulk
-        permanent relations for the remainder of a transaction that creates or
+        operations can be safely skipped, which can make those
-        rewrites them.  This can make operations much faster (see
+        operations much faster (see <xref linkend="populate-pitr">).
-        <xref linkend="populate-pitr">).  Operations that initiate this
+        Operations in which this optimization can be applied include:
-        optimization include:
         <simplelist>
-         <member><command>ALTER ... SET TABLESPACE</command></member>
+         <member><command>CREATE TABLE AS</></member>
-         <member><command>CLUSTER</command></member>
+         <member><command>CREATE INDEX</></member>
-         <member><command>CREATE TABLE</command></member>
+         <member><command>CLUSTER</></member>
-         <member><command>REFRESH MATERIALIZED VIEW</command>
+         <member><command>COPY</> into tables that were created or truncated in the same
-         (without <option>CONCURRENTLY</option>)</member>
+         transaction</member>
-         <member><command>REINDEX</command></member>
-         <member><command>TRUNCATE</command></member>
         </simplelist>
         But minimal WAL does not contain enough information to reconstruct the
         data from a base backup and the WAL logs, so <literal>replica</> or
@@ -2572,26 +2569,6 @@ include_dir 'conf.d'
       </listitem>
      </varlistentry>
 
-     <varlistentry id="guc-wal-skip-threshold" xreflabel="wal_skip_threshold">
-      <term><varname>wal_skip_threshold</varname> (<type>integer</type>)
-      <indexterm>
-       <primary><varname>wal_skip_threshold</varname> configuration parameter</primary>
-      </indexterm>
-      </term>
-      <listitem>
-       <para>
-        When <varname>wal_level</varname> is <literal>minimal</literal> and a
-        transaction commits after creating or rewriting a permanent relation,
-        this setting determines how to persist the new data.  If the data is
-        smaller than this setting, write it to the WAL log; otherwise, use an
-        fsync of affected files.  Depending on the properties of your storage,
-        raising or lowering this value might help if such commits are slowing
-        concurrent transactions.  The default is two megabytes
-        (<literal>2MB</literal>).
-       </para>
-      </listitem>
-     </varlistentry>
-
      <varlistentry id="guc-commit-delay" xreflabel="commit_delay">
       <term><varname>commit_delay</varname> (<type>integer</type>)
       <indexterm>

doc/src/sgml/perform.sgml

@@ -1394,13 +1394,42 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse;
    </para>
 
    <para>
-    Aside from avoiding the time for the archiver or WAL sender to process the
+    Aside from avoiding the time for the archiver or WAL sender to
-    WAL data, doing this will actually make certain commands faster, because
+    process the WAL data,
-    they do not to write WAL at all if <varname>wal_level</varname>
+    doing this will actually make certain commands faster, because they
-    is <literal>minimal</literal> and the current subtransaction (or top-level
+    are designed not to write WAL at all if <varname>wal_level</varname>
-    transaction) created or truncated the table or index they change.  (They
+    is <literal>minimal</>.  (They can guarantee crash safety more cheaply
-    can guarantee crash safety more cheaply by doing
+    by doing an <function>fsync</> at the end than by writing WAL.)
-    an <function>fsync</function> at the end than by writing WAL.)
+    This applies to the following commands:
+    <itemizedlist>
+     <listitem>
+      <para>
+       <command>CREATE TABLE AS SELECT</command>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       <command>CREATE INDEX</command> (and variants such as
+       <command>ALTER TABLE ADD PRIMARY KEY</command>)
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       <command>ALTER TABLE SET TABLESPACE</command>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       <command>CLUSTER</command>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       <command>COPY FROM</command>, when the target table has been
+       created or truncated earlier in the same transaction
+      </para>
+     </listitem>
+    </itemizedlist>
    </para>
   </sect2>
 

src/backend/access/gist/gistbuild.c

@@ -190,7 +190,7 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 		PageSetLSN(page, recptr);
 	}
 	else
-		PageSetLSN(page, gistGetFakeLSN(index));
+		PageSetLSN(page, gistGetFakeLSN(heap));
 
 	UnlockReleaseBuffer(buffer);
 

src/backend/access/gist/gistutil.c

@@ -937,44 +937,23 @@ gistproperty(Oid index_oid, int attno,
 }
 
 /*
- * Some indexes are not WAL-logged, but we need LSNs to detect concurrent page
+ * Temporary and unlogged GiST indexes are not WAL-logged, but we need LSNs
- * splits anyway. This function provides a fake sequence of LSNs for that
+ * to detect concurrent page splits anyway. This function provides a fake
- * purpose.
+ * sequence of LSNs for that purpose.
  */
 XLogRecPtr
 gistGetFakeLSN(Relation rel)
 {
+	static XLogRecPtr counter = 1;
+
 	if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
 	{
 		/*
 		 * Temporary relations are only accessible in our session, so a simple
 		 * backend-local counter will do.
 		 */
-		static XLogRecPtr counter = 1;
-
 		return counter++;
 	}
-	else if (rel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT)
-	{
-		/*
-		 * WAL-logging on this relation will start after commit, so its LSNs
-		 * must be distinct numbers smaller than the LSN at the next commit.
-		 * Emit a dummy WAL record if insert-LSN hasn't advanced after the
-		 * last call.
-		 */
-		static XLogRecPtr lastlsn = InvalidXLogRecPtr;
-		XLogRecPtr	currlsn = GetXLogInsertRecPtr();
-
-		/* Shouldn't be called for WAL-logging relations */
-		Assert(!RelationNeedsWAL(rel));
-
-		/* No need for an actual record if we already have a distinct LSN */
-		if (!XLogRecPtrIsInvalid(lastlsn) && lastlsn == currlsn)
-			currlsn = gistXLogAssignLSN();
-
-		lastlsn = currlsn;
-		return currlsn;
-	}
 	else
 	{
 		/*

src/backend/access/gist/gistxlog.c

@@ -480,9 +480,6 @@ gist_redo(XLogReaderState *record)
 		case XLOG_GIST_CREATE_INDEX:
 			gistRedoCreateIndex(record);
 			break;
-		case XLOG_GIST_ASSIGN_LSN:
-			/* nop. See gistGetFakeLSN(). */
-			break;
 		default:
 			elog(PANIC, "gist_redo: unknown op code %u", info);
 	}
@@ -559,23 +556,6 @@ gistXLogSplit(bool page_is_leaf,
 	return recptr;
 }
 
-/*
- * Write an empty XLOG record to assign a distinct LSN.
- */
-XLogRecPtr
-gistXLogAssignLSN(void)
-{
-	int			dummy = 0;
-
-	/*
-	 * Records other than SWITCH_WAL must have content. We use an integer 0 to
-	 * follow the restriction.
-	 */
-	XLogBeginInsert();
-	XLogRegisterData((char *) &dummy, sizeof(dummy));
-	return XLogInsert(RM_GIST_ID, XLOG_GIST_ASSIGN_LSN);
-}
-
 /*
  * Write XLOG record describing a page update. The update can include any
  * number of deletions and/or insertions of tuples on a single index page.

src/backend/access/heap/heapam.c

@@ -27,6 +27,7 @@
  *		heap_multi_insert - insert multiple tuples into a relation
  *		heap_delete		- delete a tuple from a relation
  *		heap_update		- replace a tuple in a relation with another tuple
+ *		heap_sync		- sync heap, for when no WAL has been written
  *
  * NOTES
  *	  This file contains the heap_ routines which implement
@@ -2325,6 +2326,12 @@ FreeBulkInsertState(BulkInsertState bistate)
  * The new tuple is stamped with current transaction ID and the specified
  * command ID.
  *
+ * If the HEAP_INSERT_SKIP_WAL option is specified, the new tuple is not
+ * logged in WAL, even for a non-temp relation.  Safe usage of this behavior
+ * requires that we arrange that all new tuples go into new pages not
+ * containing any tuples from other transactions, and that the relation gets
+ * fsync'd before commit.  (See also heap_sync() comments)
+ *
  * The HEAP_INSERT_SKIP_FSM option is passed directly to
  * RelationGetBufferForTuple, which see for more info.
  *
@@ -2433,7 +2440,7 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid,
 	MarkBufferDirty(buffer);
 
 	/* XLOG stuff */
-	if (RelationNeedsWAL(relation))
+	if (!(options & HEAP_INSERT_SKIP_WAL) && RelationNeedsWAL(relation))
 	{
 		xl_heap_insert xlrec;
 		xl_heap_header xlhdr;
@@ -2641,7 +2648,7 @@ heap_multi_insert(Relation relation, HeapTuple *tuples, int ntuples,
 	/* currently not needed (thus unsupported) for heap_multi_insert() */
 	AssertArg(!(options & HEAP_INSERT_NO_LOGICAL));
 
-	needwal = RelationNeedsWAL(relation);
+	needwal = !(options & HEAP_INSERT_SKIP_WAL) && RelationNeedsWAL(relation);
 	saveFreeSpace = RelationGetTargetPageFreeSpace(relation,
 												   HEAP_DEFAULT_FILLFACTOR);
 
@@ -9279,13 +9286,18 @@ heap2_redo(XLogReaderState *record)
 }
 
 /*
- *	heap_sync		- for binary compatibility
+ *	heap_sync		- sync a heap, for use when no WAL has been written
  *
- * A newer PostgreSQL version removes this function.  It exists here just in
+ * This forces the heap contents (including TOAST heap if any) down to disk.
- * case an extension calls it.  See "Skipping WAL for New RelFileNode" in
+ * If we skipped using WAL, and WAL is otherwise needed, we must force the
- * src/backend/access/transam/README for the system that superseded it,
+ * relation down to disk before it's safe to commit the transaction.  This
- * allowing removal of most calls.  Cases like copy_relation_data() should
+ * requires writing out any dirty buffers and then doing a forced fsync.
- * call smgrimmedsync() directly.
+ *
+ * Indexes are not touched.  (Currently, index operations associated with
+ * the commands that use this are WAL-logged and so do not need fsync.
+ * That behavior might change someday, but in any case it's likely that
+ * any fsync decisions required would be per-index and hence not appropriate
+ * to be done here.)
  */
 void
 heap_sync(Relation rel)

src/backend/access/heap/rewriteheap.c

@@ -143,6 +143,7 @@ typedef struct RewriteStateData
 	Page		rs_buffer;		/* page currently being built */
 	BlockNumber rs_blockno;		/* block where page will go */
 	bool		rs_buffer_valid;	/* T if any tuples in buffer */
+	bool		rs_use_wal;		/* must we WAL-log inserts? */
 	bool		rs_logical_rewrite;		/* do we need to do logical rewriting */
 	TransactionId rs_oldest_xmin;		/* oldest xmin used by caller to
 										 * determine tuple visibility */
@@ -236,13 +237,15 @@ static void logical_end_heap_rewrite(RewriteState state);
  * oldest_xmin	xid used by the caller to determine which tuples are dead
  * freeze_xid	xid before which tuples will be frozen
  * min_multi	multixact before which multis will be removed
+ * use_wal		should the inserts to the new heap be WAL-logged?
  *
  * Returns an opaque RewriteState, allocated in current memory context,
  * to be used in subsequent calls to the other functions.
  */
 RewriteState
 begin_heap_rewrite(Relation old_heap, Relation new_heap, TransactionId oldest_xmin,
-				   TransactionId freeze_xid, MultiXactId cutoff_multi)
+				   TransactionId freeze_xid, MultiXactId cutoff_multi,
+				   bool use_wal)
 {
 	RewriteState state;
 	MemoryContext rw_cxt;
@@ -267,6 +270,7 @@ begin_heap_rewrite(Relation old_heap, Relation new_heap, TransactionId oldest_xm
 	/* new_heap needn't be empty, just locked */
 	state->rs_blockno = RelationGetNumberOfBlocks(new_heap);
 	state->rs_buffer_valid = false;
+	state->rs_use_wal = use_wal;
 	state->rs_oldest_xmin = oldest_xmin;
 	state->rs_freeze_xid = freeze_xid;
 	state->rs_cutoff_multi = cutoff_multi;
@@ -325,7 +329,7 @@ end_heap_rewrite(RewriteState state)
 	/* Write the last page, if any */
 	if (state->rs_buffer_valid)
 	{
-		if (RelationNeedsWAL(state->rs_new_rel))
+		if (state->rs_use_wal)
 			log_newpage(&state->rs_new_rel->rd_node,
 						MAIN_FORKNUM,
 						state->rs_blockno,
@@ -340,14 +344,18 @@ end_heap_rewrite(RewriteState state)
 	}
 
 	/*
-	 * When we WAL-logged rel pages, we must nonetheless fsync them.  The
+	 * If the rel is WAL-logged, must fsync before commit.  We use heap_sync
+	 * to ensure that the toast table gets fsync'd too.
+	 *
+	 * It's obvious that we must do this when not WAL-logging. It's less
+	 * obvious that we have to do it even if we did WAL-log the pages. The
 	 * reason is the same as in tablecmds.c's copy_relation_data(): we're
 	 * writing data that's not in shared buffers, and so a CHECKPOINT
 	 * occurring during the rewriteheap operation won't have fsync'd data we
 	 * wrote before the checkpoint.
 	 */
 	if (RelationNeedsWAL(state->rs_new_rel))
-		smgrimmedsync(state->rs_new_rel->rd_smgr, MAIN_FORKNUM);
+		heap_sync(state->rs_new_rel);
 
 	logical_end_heap_rewrite(state);
 
@@ -644,6 +652,9 @@ raw_heap_insert(RewriteState state, HeapTuple tup)
 	{
 		int options = HEAP_INSERT_SKIP_FSM;
 
+		if (!state->rs_use_wal)
+			options |= HEAP_INSERT_SKIP_WAL;
+
 		/*
 		 * While rewriting the heap for VACUUM FULL / CLUSTER, make sure data
 		 * for the TOAST table are not logically decoded.  The main heap is
@@ -682,7 +693,7 @@ raw_heap_insert(RewriteState state, HeapTuple tup)
 			/* Doesn't fit, so write out the existing page */
 
 			/* XLOG stuff */
-			if (RelationNeedsWAL(state->rs_new_rel))
+			if (state->rs_use_wal)
 				log_newpage(&state->rs_new_rel->rd_node,
 							MAIN_FORKNUM,
 							state->rs_blockno,

src/backend/access/nbtree/nbtsort.c

@@ -40,6 +40,18 @@
  * them.  They will need to be re-read into shared buffers on first use after
  * the build finishes.
  *
+ * Since the index will never be used unless it is completely built,
+ * from a crash-recovery point of view there is no need to WAL-log the
+ * steps of the build.  After completing the index build, we can just sync
+ * the whole file to disk using smgrimmedsync() before exiting this module.
+ * This can be seen to be sufficient for crash recovery by considering that
+ * it's effectively equivalent to what would happen if a CHECKPOINT occurred
+ * just after the index build.  However, it is clearly not sufficient if the
+ * DBA is using the WAL log for PITR or replication purposes, since another
+ * machine would not be able to reconstruct the index from WAL.  Therefore,
+ * we log the completed index pages to WAL if and only if WAL archiving is
+ * active.
+ *
  * This code isn't concerned about the FSM at all. The caller is responsible
  * for initializing that.
  *
@@ -204,7 +216,12 @@ _bt_leafbuild(BTSpool *btspool, BTSpool *btspool2)
 
 	wstate.heap = btspool->heap;
 	wstate.index = btspool->index;
-	wstate.btws_use_wal = RelationNeedsWAL(wstate.index);
+
+	/*
+	 * We need to log index creation in WAL iff WAL archiving/streaming is
+	 * enabled UNLESS the index isn't WAL-logged anyway.
+	 */
+	wstate.btws_use_wal = XLogIsNeeded() && RelationNeedsWAL(wstate.index);
 
 	/* reserve the metapage */
 	wstate.btws_pages_alloced = BTREE_METAPAGE + 1;
@@ -794,15 +811,21 @@ _bt_load(BTWriteState *wstate, BTSpool *btspool, BTSpool *btspool2)
 	_bt_uppershutdown(wstate, state);
 
 	/*
-	 * When we WAL-logged index pages, we must nonetheless fsync index files.
+	 * If the index is WAL-logged, we must fsync it down to disk before it's
-	 * Since we're building outside shared buffers, a CHECKPOINT occurring
+	 * safe to commit the transaction.  (For a non-WAL-logged index we don't
-	 * during the build has no way to flush the previously written data to
+	 * care since the index will be uninteresting after a crash anyway.)
-	 * disk (indeed it won't know the index even exists).  A crash later on
+	 *
-	 * would replay WAL from the checkpoint, therefore it wouldn't replay our
+	 * It's obvious that we must do this when not WAL-logging the build. It's
-	 * earlier WAL entries. If we do not fsync those pages here, they might
+	 * less obvious that we have to do it even if we did WAL-log the index
-	 * still not be on disk when the crash occurs.
+	 * pages.  The reason is that since we're building outside shared buffers,
+	 * a CHECKPOINT occurring during the build has no way to flush the
+	 * previously written data to disk (indeed it won't know the index even
+	 * exists).  A crash later on would replay WAL from the checkpoint,
+	 * therefore it wouldn't replay our earlier WAL entries. If we do not
+	 * fsync those pages here, they might still not be on disk when the crash
+	 * occurs.
 	 */
-	if (wstate->btws_use_wal)
+	if (RelationNeedsWAL(wstate->index))
 	{
 		RelationOpenSmgr(wstate->index);
 		smgrimmedsync(wstate->index->rd_smgr, MAIN_FORKNUM);

src/backend/access/rmgrdesc/gistdesc.c

@@ -46,9 +46,6 @@ gist_desc(StringInfo buf, XLogReaderState *record)
 			break;
 		case XLOG_GIST_CREATE_INDEX:
 			break;
-		case XLOG_GIST_ASSIGN_LSN:
-			/* No details to write out */
-			break;
 	}
 }
 
@@ -68,9 +65,6 @@ gist_identify(uint8 info)
 		case XLOG_GIST_CREATE_INDEX:
 			id = "CREATE_INDEX";
 			break;
-		case XLOG_GIST_ASSIGN_LSN:
-			id = "ASSIGN_LSN";
-			break;
 	}
 
 	return id;

src/backend/access/transam/README

@@ -717,38 +717,6 @@ then restart recovery.  This is part of the reason for not writing a WAL
 entry until we've successfully done the original action.
 
 
-Skipping WAL for New RelFileNode
---------------------------------
-
-Under wal_level=minimal, if a change modifies a relfilenode that ROLLBACK
-would unlink, in-tree access methods write no WAL for that change.  Code that
-writes WAL without calling RelationNeedsWAL() must check for this case.  This
-skipping is mandatory.  If a WAL-writing change preceded a WAL-skipping change
-for the same block, REDO could overwrite the WAL-skipping change.  If a
-WAL-writing change followed a WAL-skipping change for the same block, a
-related problem would arise.  When a WAL record contains no full-page image,
-REDO expects the page to match its contents from just before record insertion.
-A WAL-skipping change may not reach disk at all, violating REDO's expectation
-under full_page_writes=off.  For any access method, CommitTransaction() writes
-and fsyncs affected blocks before recording the commit.
-
-Prefer to do the same in future access methods.  However, two other approaches
-can work.  First, an access method can irreversibly transition a given fork
-from WAL-skipping to WAL-writing by calling FlushRelationBuffers() and
-smgrimmedsync().  Second, an access method can opt to write WAL
-unconditionally for permanent relations.  Under these approaches, the access
-method callbacks must not call functions that react to RelationNeedsWAL().
-
-This applies only to WAL records whose replay would modify bytes stored in the
-new relfilenode.  It does not apply to other records about the relfilenode,
-such as XLOG_SMGR_CREATE.  Because it operates at the level of individual
-relfilenodes, RelationNeedsWAL() can differ for tightly-coupled relations.
-Consider "CREATE TABLE t (); BEGIN; ALTER TABLE t ADD c text; ..." in which
-ALTER TABLE adds a TOAST relation.  The TOAST relation will skip WAL, while
-the table owning it will not.  ALTER TABLE SET TABLESPACE will cause a table
-to skip WAL, but that won't affect its indexes.
-
-
 Asynchronous Commit
 -------------------
 
@@ -852,12 +820,13 @@ Changes to a temp table are not WAL-logged, hence could reach disk in
 advance of T1's commit, but we don't care since temp table contents don't
 survive crashes anyway.
 
-Database writes that skip WAL for new relfilenodes are also safe.  In these
+Database writes made via any of the paths we have introduced to avoid WAL
-cases it's entirely possible for the data to reach disk before T1's commit,
+overhead for bulk updates are also safe.  In these cases it's entirely
-because T1 will fsync it down to disk without any sort of interlock.  However,
+possible for the data to reach disk before T1's commit, because T1 will
-all these paths are designed to write data that no other transaction can see
+fsync it down to disk without any sort of interlock, as soon as it finishes
-until after T1 commits.  The situation is thus not different from ordinary
+the bulk update.  However, all these paths are designed to write data that
-WAL-logged updates.
+no other transaction can see until after T1 commits.  The situation is thus
+not different from ordinary WAL-logged updates.
 
 Transaction Emulation during Recovery
 -------------------------------------

src/backend/access/transam/xact.c

@@ -2032,13 +2032,6 @@ CommitTransaction(void)
 	 */
 	PreCommit_on_commit_actions();
 
-	/*
-	 * Synchronize files that are created and not WAL-logged during this
-	 * transaction. This must happen before AtEOXact_RelationMap(), so that we
-	 * don't see committed-but-broken files after a crash.
-	 */
-	smgrDoPendingSyncs(true);
-
 	/* close large objects before lower-level cleanup */
 	AtEOXact_LargeObject(true);
 
@@ -2267,13 +2260,6 @@ PrepareTransaction(void)
 	 */
 	PreCommit_on_commit_actions();
 
-	/*
-	 * Synchronize files that are created and not WAL-logged during this
-	 * transaction. This must happen before EndPrepare(), so that we don't see
-	 * committed-but-broken files after a crash and COMMIT PREPARED.
-	 */
-	smgrDoPendingSyncs(true);
-
 	/* close large objects before lower-level cleanup */
 	AtEOXact_LargeObject(true);
 
@@ -2574,7 +2560,6 @@ AbortTransaction(void)
 	 */
 	AfterTriggerEndXact(false); /* 'false' means it's abort */
 	AtAbort_Portals();
-	smgrDoPendingSyncs(false);
 	AtEOXact_LargeObject(false);
 	AtAbort_Notify();
 	AtEOXact_RelationMap(false);

src/backend/access/transam/xlogutils.c

@@ -542,8 +542,6 @@ typedef FakeRelCacheEntryData *FakeRelCacheEntry;
  * fields related to physical storage, like rd_rel, are initialized, so the
  * fake entry is only usable in low-level operations like ReadBuffer().
  *
- * This is also used for syncing WAL-skipped files.
- *
  * Caller must free the returned entry with FreeFakeRelcacheEntry().
  */
 Relation
@@ -552,20 +550,18 @@ CreateFakeRelcacheEntry(RelFileNode rnode)
 	FakeRelCacheEntry fakeentry;
 	Relation	rel;
 
+	Assert(InRecovery);
+
 	/* Allocate the Relation struct and all related space in one block. */
 	fakeentry = palloc0(sizeof(FakeRelCacheEntryData));
 	rel = (Relation) fakeentry;
 
 	rel->rd_rel = &fakeentry->pgc;
 	rel->rd_node = rnode;
-
+	/* We will never be working with temp rels during recovery */
-	/*
-	 * We will never be working with temp rels during recovery or while
-	 * syncing WAL-skipped files.
-	 */
 	rel->rd_backend = InvalidBackendId;
 
-	/* It must be a permanent table here */
+	/* It must be a permanent table if we're in recovery. */
 	rel->rd_rel->relpersistence = RELPERSISTENCE_PERMANENT;
 
 	/* We don't know the name of the relation; use relfilenode instead */
@@ -574,9 +570,9 @@ CreateFakeRelcacheEntry(RelFileNode rnode)
 	/*
 	 * We set up the lockRelId in case anything tries to lock the dummy
 	 * relation.  Note that this is fairly bogus since relNode may be
-	 * different from the relation's OID.  It shouldn't really matter though.
+	 * different from the relation's OID.  It shouldn't really matter though,
-	 * In recovery, we are running by ourselves and can't have any lock
+	 * since we are presumably running by ourselves and can't have any lock
-	 * conflicts.  While syncing, we already hold AccessExclusiveLock.
+	 * conflicts ...
 	 */
 	rel->rd_lockInfo.lockRelId.dbId = rnode.dbNode;
 	rel->rd_lockInfo.lockRelId.relId = rnode.relNode;

src/backend/bootstrap/bootparse.y

@@ -299,8 +299,6 @@ Boot_DeclareIndexStmt:
 					stmt->idxcomment = NULL;
 					stmt->indexOid = InvalidOid;
 					stmt->oldNode = InvalidOid;
-					stmt->oldCreateSubid = InvalidSubTransactionId;
-					stmt->oldFirstRelfilenodeSubid = InvalidSubTransactionId;
 					stmt->unique = false;
 					stmt->primary = false;
 					stmt->isconstraint = false;
@@ -344,8 +342,6 @@ Boot_DeclareUniqueIndexStmt:
 					stmt->idxcomment = NULL;
 					stmt->indexOid = InvalidOid;
 					stmt->oldNode = InvalidOid;
-					stmt->oldCreateSubid = InvalidSubTransactionId;
-					stmt->oldFirstRelfilenodeSubid = InvalidSubTransactionId;
 					stmt->unique = true;
 					stmt->primary = false;
 					stmt->isconstraint = false;

src/backend/catalog/storage.c

@@ -27,16 +27,11 @@
 #include "catalog/catalog.h"
 #include "catalog/storage.h"
 #include "catalog/storage_xlog.h"
-#include "miscadmin.h"
 #include "storage/freespace.h"
 #include "storage/smgr.h"
-#include "utils/hsearch.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 
-/* GUC variables */
-int			wal_skip_threshold = 2048;	/* in kilobytes */
-
 /*
  * We keep a list of all relations (represented as RelFileNode values)
  * that have been created or deleted in the current transaction.  When
@@ -66,14 +61,7 @@ typedef struct PendingRelDelete
 	struct PendingRelDelete *next;		/* linked-list link */
 } PendingRelDelete;
 
-typedef struct pendingSync
-{
-	RelFileNode rnode;
-	bool		is_truncated;	/* Has the file experienced truncation? */
-} pendingSync;
-
 static PendingRelDelete *pendingDeletes = NULL; /* head of linked list */
-HTAB	   *pendingSyncHash = NULL;
 
 /*
  * RelationCreateStorage
@@ -128,37 +116,6 @@ RelationCreateStorage(RelFileNode rnode, char relpersistence)
 	pending->nestLevel = GetCurrentTransactionNestLevel();
 	pending->next = pendingDeletes;
 	pendingDeletes = pending;
-
-	/*
-	 * Queue an at-commit sync.  Bootstrap does not need syncs, because initdb
-	 * syncs at the end.  During bootstrap, mdexists() creates the specified
-	 * file; smgrDoPendingSyncs() would not cope with that.
-	 */
-	if (relpersistence == RELPERSISTENCE_PERMANENT && !XLogIsNeeded() &&
-		!IsBootstrapProcessingMode())
-	{
-		pendingSync *pending;
-		bool		found;
-
-		/* we sync only permanent relations */
-		Assert(backend == InvalidBackendId);
-
-		if (!pendingSyncHash)
-		{
-			HASHCTL		ctl;
-
-			ctl.keysize = sizeof(RelFileNode);
-			ctl.entrysize = sizeof(pendingSync);
-			ctl.hcxt = TopTransactionContext;
-			pendingSyncHash =
-				hash_create("pending sync hash",
-							16, &ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
-		}
-
-		pending = hash_search(pendingSyncHash, &rnode, HASH_ENTER, &found);
-		Assert(!found);
-		pending->is_truncated = false;
-	}
 }
 
 /*
@@ -292,8 +249,6 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
 	if (vm)
 		visibilitymap_truncate(rel, nblocks);
 
-	RelationPreTruncate(rel);
-
 	/*
 	 * We WAL-log the truncation before actually truncating, which means
 	 * trouble if the truncation fails. If we then crash, the WAL replay
@@ -336,49 +291,6 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
 	smgrtruncate(rel->rd_smgr, MAIN_FORKNUM, nblocks);
 }
 
-/*
- * RelationPreTruncate
- *		Perform AM-independent work before a physical truncation.
- *
- * If an access method's relation_nontransactional_truncate does not call
- * RelationTruncate(), it must call this before decreasing the table size.
- */
-void
-RelationPreTruncate(Relation rel)
-{
-	pendingSync *pending;
-
-	if (!pendingSyncHash)
-		return;
-	RelationOpenSmgr(rel);
-
-	pending = hash_search(pendingSyncHash, &(rel->rd_smgr->smgr_rnode.node),
-						  HASH_FIND, NULL);
-	if (pending)
-		pending->is_truncated = true;
-}
-
-/*
- * RelFileNodeSkippingWAL - check if a BM_PERMANENT relfilenode is using WAL
- *
- *   Changes of certain relfilenodes must not write WAL; see "Skipping WAL for
- *   New RelFileNode" in src/backend/access/transam/README.  Though it is
- *   known from Relation efficiently, this function is intended for the code
- *   paths not having access to Relation.
- */
-bool
-RelFileNodeSkippingWAL(RelFileNode rnode)
-{
-	if (XLogIsNeeded())
-		return false;			/* no permanent relfilenode skips WAL */
-
-	if (!pendingSyncHash ||
-		hash_search(pendingSyncHash, &rnode, HASH_FIND, NULL) == NULL)
-		return false;
-
-	return true;
-}
-
 /*
  *	smgrDoPendingDeletes() -- Take care of relation deletes at end of xact.
  *
@@ -456,144 +368,6 @@ smgrDoPendingDeletes(bool isCommit)
 	}
 }
 
-/*
- *	smgrDoPendingSyncs() -- Take care of relation syncs at end of xact.
- */
-void
-smgrDoPendingSyncs(bool isCommit)
-{
-	PendingRelDelete *pending;
-	int			nrels = 0,
-				maxrels = 0;
-	SMgrRelation *srels = NULL;
-	HASH_SEQ_STATUS scan;
-	pendingSync *pendingsync;
-
-	if (XLogIsNeeded())
-		return;					/* no relation can use this */
-
-	Assert(GetCurrentTransactionNestLevel() == 1);
-
-	if (!pendingSyncHash)
-		return;					/* no relation needs sync */
-
-	/* Just throw away all pending syncs if any at rollback */
-	if (!isCommit)
-	{
-		pendingSyncHash = NULL;
-		return;
-	}
-
-	AssertPendingSyncs_RelationCache();
-
-	/* Skip syncing nodes that smgrDoPendingDeletes() will delete. */
-	for (pending = pendingDeletes; pending != NULL; pending = pending->next)
-	{
-		if (!pending->atCommit)
-			continue;
-
-		(void) hash_search(pendingSyncHash, (void *) &pending->relnode,
-						   HASH_REMOVE, NULL);
-	}
-
-	hash_seq_init(&scan, pendingSyncHash);
-	while ((pendingsync = (pendingSync *) hash_seq_search(&scan)))
-	{
-		ForkNumber	fork;
-		BlockNumber nblocks[MAX_FORKNUM + 1];
-		BlockNumber total_blocks = 0;
-		SMgrRelation srel;
-
-		srel = smgropen(pendingsync->rnode, InvalidBackendId);
-
-		/*
-		 * We emit newpage WAL records for smaller relations.
-		 *
-		 * Small WAL records have a chance to be emitted along with other
-		 * backends' WAL records.  We emit WAL records instead of syncing for
-		 * files that are smaller than a certain threshold, expecting faster
-		 * commit.  The threshold is defined by the GUC wal_skip_threshold.
-		 */
-		if (!pendingsync->is_truncated)
-		{
-			for (fork = 0; fork <= MAX_FORKNUM; fork++)
-			{
-				if (smgrexists(srel, fork))
-				{
-					BlockNumber n = smgrnblocks(srel, fork);
-
-					/* we shouldn't come here for unlogged relations */
-					Assert(fork != INIT_FORKNUM);
-					nblocks[fork] = n;
-					total_blocks += n;
-				}
-				else
-					nblocks[fork] = InvalidBlockNumber;
-			}
-		}
-
-		/*
-		 * Sync file or emit WAL records for its contents.
-		 *
-		 * Although we emit WAL record if the file is small enough, do file
-		 * sync regardless of the size if the file has experienced a
-		 * truncation. It is because the file would be followed by trailing
-		 * garbage blocks after a crash recovery if, while a past longer file
-		 * had been flushed out, we omitted syncing-out of the file and
-		 * emitted WAL instead.  You might think that we could choose WAL if
-		 * the current main fork is longer than ever, but there's a case where
-		 * main fork is longer than ever but FSM fork gets shorter.
-		 */
-		if (pendingsync->is_truncated ||
-			total_blocks * BLCKSZ / 1024 >= wal_skip_threshold)
-		{
-			/* allocate the initial array, or extend it, if needed */
-			if (maxrels == 0)
-			{
-				maxrels = 8;
-				srels = palloc(sizeof(SMgrRelation) * maxrels);
-			}
-			else if (maxrels <= nrels)
-			{
-				maxrels *= 2;
-				srels = repalloc(srels, sizeof(SMgrRelation) * maxrels);
-			}
-
-			srels[nrels++] = srel;
-		}
-		else
-		{
-			/* Emit WAL records for all blocks.  The file is small enough. */
-			for (fork = 0; fork <= MAX_FORKNUM; fork++)
-			{
-				int			n = nblocks[fork];
-				Relation	rel;
-
-				if (!BlockNumberIsValid(n))
-					continue;
-
-				/*
-				 * Emit WAL for the whole file.  Unfortunately we don't know
-				 * what kind of a page this is, so we have to log the full
-				 * page including any unused space.  ReadBufferExtended()
-				 * counts some pgstat events; unfortunately, we discard them.
-				 */
-				rel = CreateFakeRelcacheEntry(srel->smgr_rnode.node);
-				log_newpage_range(rel, fork, 0, n, false);
-				FreeFakeRelcacheEntry(rel);
-			}
-		}
-	}
-
-	pendingSyncHash = NULL;
-
-	if (nrels > 0)
-	{
-		smgrdosyncall(srels, nrels);
-		pfree(srels);
-	}
-}
-
 /*
  * smgrGetPendingDeletes() -- Get a list of non-temp relations to be deleted.
  *

src/backend/commands/cluster.c

@@ -747,6 +747,7 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex, bool verbose,
 	bool	   *isnull;
 	IndexScanDesc indexScan;
 	HeapScanDesc heapScan;
+	bool		use_wal;
 	bool		is_system_catalog;
 	TransactionId OldestXmin;
 	TransactionId FreezeXid;
@@ -802,9 +803,12 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex, bool verbose,
 		LockRelationOid(OldHeap->rd_rel->reltoastrelid, AccessExclusiveLock);
 
 	/*
-	 * Valid smgr_targblock implies something already wrote to the relation.
+	 * We need to log the copied data in WAL iff WAL archiving/streaming is
-	 * This may be harmless, but this function hasn't planned for it.
+	 * enabled AND it's a WAL-logged rel.
 	 */
+	use_wal = XLogIsNeeded() && RelationNeedsWAL(NewHeap);
+
+	/* use_wal off requires smgr_targblock be initially invalid */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
 	/*
@@ -872,7 +876,7 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex, bool verbose,
 
 	/* Initialize the rewrite operation */
 	rwstate = begin_heap_rewrite(OldHeap, NewHeap, OldestXmin, FreezeXid,
-								 MultiXactCutoff);
+								 MultiXactCutoff, use_wal);
 
 	/*
 	 * Decide whether to use an indexscan or seqscan-and-optional-sort to scan
@@ -1242,25 +1246,6 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
 		*mapped_tables++ = r2;
 	}
 
-	/*
-	 * Recognize that rel1's relfilenode (swapped from rel2) is new in this
-	 * subtransaction. The rel2 storage (swapped from rel1) may or may not be
-	 * new.
-	 */
-	{
-		Relation	rel1,
-					rel2;
-
-		rel1 = relation_open(r1, NoLock);
-		rel2 = relation_open(r2, NoLock);
-		rel2->rd_createSubid = rel1->rd_createSubid;
-		rel2->rd_newRelfilenodeSubid = rel1->rd_newRelfilenodeSubid;
-		rel2->rd_firstRelfilenodeSubid = rel1->rd_firstRelfilenodeSubid;
-		RelationAssumeNewRelfilenode(rel1);
-		relation_close(rel1, NoLock);
-		relation_close(rel2, NoLock);
-	}
-
 	/*
 	 * In the case of a shared catalog, these next few steps will only affect
 	 * our own database's pg_class row; but that's okay, because they are all

src/backend/commands/copy.c

@@ -2310,14 +2310,49 @@ CopyFrom(CopyState cstate)
 
 	tupDesc = RelationGetDescr(cstate->rel);
 
-	/*
+	/*----------
-	 * If the target file is new-in-transaction, we assume that checking FSM
+	 * Check to see if we can avoid writing WAL
-	 * for free space is a waste of time.  This could possibly be wrong, but
+	 *
-	 * it's unlikely.
+	 * If archive logging/streaming is not enabled *and* either
+	 *	- table was created in same transaction as this COPY
+	 *	- data is being written to relfilenode created in this transaction
+	 * then we can skip writing WAL.  It's safe because if the transaction
+	 * doesn't commit, we'll discard the table (or the new relfilenode file).
+	 * If it does commit, we'll have done the heap_sync at the bottom of this
+	 * routine first.
+	 *
+	 * As mentioned in comments in utils/rel.h, the in-same-transaction test
+	 * is not always set correctly, since in rare cases rd_newRelfilenodeSubid
+	 * can be cleared before the end of the transaction. The exact case is
+	 * when a relation sets a new relfilenode twice in same transaction, yet
+	 * the second one fails in an aborted subtransaction, e.g.
+	 *
+	 * BEGIN;
+	 * TRUNCATE t;
+	 * SAVEPOINT save;
+	 * TRUNCATE t;
+	 * ROLLBACK TO save;
+	 * COPY ...
+	 *
+	 * Also, if the target file is new-in-transaction, we assume that checking
+	 * FSM for free space is a waste of time, even if we must use WAL because
+	 * of archiving.  This could possibly be wrong, but it's unlikely.
+	 *
+	 * The comments for heap_insert and RelationGetBufferForTuple specify that
+	 * skipping WAL logging is only safe if we ensure that our tuples do not
+	 * go into pages containing tuples from any other transactions --- but this
+	 * must be the case if we have a new table or new relfilenode, so we need
+	 * no additional work to enforce that.
+	 *----------
 	 */
+	/* createSubid is creation check, newRelfilenodeSubid is truncation check */
 	if (cstate->rel->rd_createSubid != InvalidSubTransactionId ||
-		cstate->rel->rd_firstRelfilenodeSubid != InvalidSubTransactionId)
+		cstate->rel->rd_newRelfilenodeSubid != InvalidSubTransactionId)
+	{
 		hi_options |= HEAP_INSERT_SKIP_FSM;
+		if (!XLogIsNeeded())
+			hi_options |= HEAP_INSERT_SKIP_WAL;
+	}
 
 	/*
 	 * Optimize if new relfilenode was created in this subxact or one of its
@@ -2576,6 +2611,13 @@ CopyFrom(CopyState cstate)
 
 	FreeExecutorState(estate);
 
+	/*
+	 * If we skipped writing WAL, then we need to sync the heap (but not
+	 * indexes since those use WAL anyway)
+	 */
+	if (hi_options & HEAP_INSERT_SKIP_WAL)
+		heap_sync(cstate->rel);
+
 	return processed;
 }
 

src/backend/commands/createas.c

@@ -562,13 +562,16 @@ intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
 	myState->rel = intoRelationDesc;
 	myState->reladdr = intoRelationAddr;
 	myState->output_cid = GetCurrentCommandId(true);
-	myState->hi_options = HEAP_INSERT_SKIP_FSM;
-	myState->bistate = GetBulkInsertState();
 
 	/*
-	 * Valid smgr_targblock implies something already wrote to the relation.
+	 * We can skip WAL-logging the insertions, unless PITR or streaming
-	 * This may be harmless, but this function hasn't planned for it.
+	 * replication is in use. We can skip the FSM in any case.
 	 */
+	myState->hi_options = HEAP_INSERT_SKIP_FSM |
+		(XLogIsNeeded() ? 0 : HEAP_INSERT_SKIP_WAL);
+	myState->bistate = GetBulkInsertState();
+
+	/* Not using WAL requires smgr_targblock be initially invalid */
 	Assert(RelationGetTargetBlock(intoRelationDesc) == InvalidBlockNumber);
 }
 
@@ -614,6 +617,10 @@ intorel_shutdown(DestReceiver *self)
 
 	FreeBulkInsertState(myState->bistate);
 
+	/* If we skipped using WAL, must heap_sync before commit */
+	if (myState->hi_options & HEAP_INSERT_SKIP_WAL)
+		heap_sync(myState->rel);
+
 	/* close rel, but keep lock until commit */
 	heap_close(myState->rel, NoLock);
 	myState->rel = NULL;

src/backend/commands/matview.c

@@ -436,13 +436,17 @@ transientrel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
 	 */
 	myState->transientrel = transientrel;
 	myState->output_cid = GetCurrentCommandId(true);
-	myState->hi_options = HEAP_INSERT_SKIP_FSM | HEAP_INSERT_FROZEN;
-	myState->bistate = GetBulkInsertState();
 
 	/*
-	 * Valid smgr_targblock implies something already wrote to the relation.
+	 * We can skip WAL-logging the insertions, unless PITR or streaming
-	 * This may be harmless, but this function hasn't planned for it.
+	 * replication is in use. We can skip the FSM in any case.
 	 */
+	myState->hi_options = HEAP_INSERT_SKIP_FSM | HEAP_INSERT_FROZEN;
+	if (!XLogIsNeeded())
+		myState->hi_options |= HEAP_INSERT_SKIP_WAL;
+	myState->bistate = GetBulkInsertState();
+
+	/* Not using WAL requires smgr_targblock be initially invalid */
 	Assert(RelationGetTargetBlock(transientrel) == InvalidBlockNumber);
 }
 
@@ -482,6 +486,10 @@ transientrel_shutdown(DestReceiver *self)
 
 	FreeBulkInsertState(myState->bistate);
 
+	/* If we skipped using WAL, must heap_sync before commit */
+	if (myState->hi_options & HEAP_INSERT_SKIP_WAL)
+		heap_sync(myState->transientrel);
+
 	/* close transientrel, but keep lock until commit */
 	heap_close(myState->transientrel, NoLock);
 	myState->transientrel = NULL;

src/backend/commands/tablecmds.c

@@ -4021,14 +4021,19 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 		newrel = NULL;
 
 	/*
-	 * Prepare a BulkInsertState and options for heap_insert.  The FSM is
+	 * Prepare a BulkInsertState and options for heap_insert. Because we're
-	 * empty, so don't bother using it.
+	 * building a new heap, we can skip WAL-logging and fsync it to disk at
+	 * the end instead (unless WAL-logging is required for archiving or
+	 * streaming replication). The FSM is empty too, so don't bother using it.
 	 */
 	if (newrel)
 	{
 		mycid = GetCurrentCommandId(true);
 		bistate = GetBulkInsertState();
+
 		hi_options = HEAP_INSERT_SKIP_FSM;
+		if (!XLogIsNeeded())
+			hi_options |= HEAP_INSERT_SKIP_WAL;
 	}
 	else
 	{
@@ -4278,6 +4283,10 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 	{
 		FreeBulkInsertState(bistate);
 
+		/* If we skipped writing WAL, then we need to sync the heap. */
+		if (hi_options & HEAP_INSERT_SKIP_WAL)
+			heap_sync(newrel);
+
 		heap_close(newrel, NoLock);
 	}
 }
@@ -5979,19 +5988,14 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
 
 	/*
 	 * If TryReuseIndex() stashed a relfilenode for us, we used it for the new
-	 * index instead of building from scratch.  Restore associated fields.
+	 * index instead of building from scratch.  The DROP of the old edition of
-	 * This may store InvalidSubTransactionId in both fields, in which case
+	 * this index will have scheduled the storage for deletion at commit, so
-	 * relcache.c will assume it can rebuild the relcache entry.  Hence, do
+	 * cancel that pending deletion.
-	 * this after the CCI that made catalog rows visible to any rebuild.  The
-	 * DROP of the old edition of this index will have scheduled the storage
-	 * for deletion at commit, so cancel that pending deletion.
 	 */
 	if (OidIsValid(stmt->oldNode))
 	{
 		Relation	irel = index_open(address.objectId, NoLock);
 
-		irel->rd_createSubid = stmt->oldCreateSubid;
-		irel->rd_firstRelfilenodeSubid = stmt->oldFirstRelfilenodeSubid;
 		RelationPreserveStorage(irel->rd_node, true);
 		index_close(irel, NoLock);
 	}
@@ -9130,8 +9134,6 @@ TryReuseIndex(Oid oldId, IndexStmt *stmt)
 		Relation	irel = index_open(oldId, NoLock);
 
 		stmt->oldNode = irel->rd_node.relNode;
-		stmt->oldCreateSubid = irel->rd_createSubid;
-		stmt->oldFirstRelfilenodeSubid = irel->rd_firstRelfilenodeSubid;
 		index_close(irel, NoLock);
 	}
 }
@@ -9977,8 +9979,6 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode)
 
 	heap_close(pg_class, RowExclusiveLock);
 
-	RelationAssumeNewRelfilenode(rel);
-
 	relation_close(rel, NoLock);
 
 	/* Make sure the reltablespace change is visible */
@@ -10193,9 +10193,7 @@ copy_relation_data(SMgrRelation src, SMgrRelation dst,
 
 	/*
 	 * We need to log the copied data in WAL iff WAL archiving/streaming is
-	 * enabled AND it's a permanent relation.  This gives the same answer as
+	 * enabled AND it's a permanent relation.
-	 * "RelationNeedsWAL(rel) || copying_initfork", because we know the
-	 * current operation created a new relfilenode.
 	 */
 	use_wal = XLogIsNeeded() &&
 		(relpersistence == RELPERSISTENCE_PERMANENT || copying_initfork);
@@ -10237,15 +10235,21 @@ copy_relation_data(SMgrRelation src, SMgrRelation dst,
 	}
 
 	/*
-	 * When we WAL-logged rel pages, we must nonetheless fsync them.  The
+	 * If the rel is WAL-logged, must fsync before commit.  We use heap_sync
-	 * reason is that since we're copying outside shared buffers, a CHECKPOINT
+	 * to ensure that the toast table gets fsync'd too.  (For a temp or
-	 * occurring during the copy has no way to flush the previously written
+	 * unlogged rel we don't care since the data will be gone after a crash
-	 * data to disk (indeed it won't know the new rel even exists).  A crash
+	 * anyway.)
-	 * later on would replay WAL from the checkpoint, therefore it wouldn't
+	 *
-	 * replay our earlier WAL entries. If we do not fsync those pages here,
+	 * It's obvious that we must do this when not WAL-logging the copy. It's
-	 * they might still not be on disk when the crash occurs.
+	 * less obvious that we have to do it even if we did WAL-log the copied
+	 * pages. The reason is that since we're copying outside shared buffers, a
+	 * CHECKPOINT occurring during the copy has no way to flush the previously
+	 * written data to disk (indeed it won't know the new rel even exists).  A
+	 * crash later on would replay WAL from the checkpoint, therefore it
+	 * wouldn't replay our earlier WAL entries. If we do not fsync those pages
+	 * here, they might still not be on disk when the crash occurs.
 	 */
-	if (use_wal || copying_initfork)
+	if (relpersistence == RELPERSISTENCE_PERMANENT || copying_initfork)
 		smgrimmedsync(dst, forkNum);
 }
 

src/backend/nodes/copyfuncs.c

@@ -3126,8 +3126,6 @@ _copyIndexStmt(const IndexStmt *from)
 	COPY_STRING_FIELD(idxcomment);
 	COPY_SCALAR_FIELD(indexOid);
 	COPY_SCALAR_FIELD(oldNode);
-	COPY_SCALAR_FIELD(oldCreateSubid);
-	COPY_SCALAR_FIELD(oldFirstRelfilenodeSubid);
 	COPY_SCALAR_FIELD(unique);
 	COPY_SCALAR_FIELD(primary);
 	COPY_SCALAR_FIELD(isconstraint);

src/backend/nodes/equalfuncs.c

@@ -1259,8 +1259,6 @@ _equalIndexStmt(const IndexStmt *a, const IndexStmt *b)
 	COMPARE_STRING_FIELD(idxcomment);
 	COMPARE_SCALAR_FIELD(indexOid);
 	COMPARE_SCALAR_FIELD(oldNode);
-	COMPARE_SCALAR_FIELD(oldCreateSubid);
-	COMPARE_SCALAR_FIELD(oldFirstRelfilenodeSubid);
 	COMPARE_SCALAR_FIELD(unique);
 	COMPARE_SCALAR_FIELD(primary);
 	COMPARE_SCALAR_FIELD(isconstraint);

src/backend/nodes/outfuncs.c

@@ -2452,8 +2452,6 @@ _outIndexStmt(StringInfo str, const IndexStmt *node)
 	WRITE_STRING_FIELD(idxcomment);
 	WRITE_OID_FIELD(indexOid);
 	WRITE_OID_FIELD(oldNode);
-	WRITE_UINT_FIELD(oldCreateSubid);
-	WRITE_UINT_FIELD(oldFirstRelfilenodeSubid);
 	WRITE_BOOL_FIELD(unique);
 	WRITE_BOOL_FIELD(primary);
 	WRITE_BOOL_FIELD(isconstraint);

src/backend/parser/gram.y

@@ -6664,8 +6664,6 @@ IndexStmt:	CREATE opt_unique INDEX opt_concurrently opt_index_name
 					n->idxcomment = NULL;
 					n->indexOid = InvalidOid;
 					n->oldNode = InvalidOid;
-					n->oldCreateSubid = InvalidSubTransactionId;
-					n->oldFirstRelfilenodeSubid = InvalidSubTransactionId;
 					n->primary = false;
 					n->isconstraint = false;
 					n->deferrable = false;
@@ -6692,8 +6690,6 @@ IndexStmt:	CREATE opt_unique INDEX opt_concurrently opt_index_name
 					n->idxcomment = NULL;
 					n->indexOid = InvalidOid;
 					n->oldNode = InvalidOid;
-					n->oldCreateSubid = InvalidSubTransactionId;
-					n->oldFirstRelfilenodeSubid = InvalidSubTransactionId;
 					n->primary = false;
 					n->isconstraint = false;
 					n->deferrable = false;

src/backend/parser/parse_utilcmd.c

@@ -1121,8 +1121,6 @@ generateClonedIndexStmt(CreateStmtContext *cxt, Relation source_idx,
 	index->idxcomment = NULL;
 	index->indexOid = InvalidOid;
 	index->oldNode = InvalidOid;
-	index->oldCreateSubid = InvalidSubTransactionId;
-	index->oldFirstRelfilenodeSubid = InvalidSubTransactionId;
 	index->unique = idxrec->indisunique;
 	index->primary = idxrec->indisprimary;
 	index->transformed = true;	/* don't need transformIndexStmt */
@@ -1588,8 +1586,6 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt)
 	index->idxcomment = NULL;
 	index->indexOid = InvalidOid;
 	index->oldNode = InvalidOid;
-	index->oldCreateSubid = InvalidSubTransactionId;
-	index->oldFirstRelfilenodeSubid = InvalidSubTransactionId;
 	index->transformed = false;
 	index->concurrent = false;
 	index->if_not_exists = false;

src/backend/storage/buffer/bufmgr.c

@@ -65,7 +65,7 @@
 #define BUF_WRITTEN				0x01
 #define BUF_REUSABLE			0x02
 
-#define RELS_BSEARCH_THRESHOLD		20
+#define DROP_RELS_BSEARCH_THRESHOLD		20
 
 typedef struct PrivateRefCountEntry
 {
@@ -104,19 +104,6 @@ typedef struct CkptTsStatus
 	int			index;
 } CkptTsStatus;
 
-/*
- * Type for array used to sort SMgrRelations
- *
- * FlushRelationsAllBuffers shares the same comparator function with
- * DropRelFileNodesAllBuffers. Pointer to this struct and RelFileNode must be
- * compatible.
- */
-typedef struct SMgrSortArray
-{
-	RelFileNode rnode;			/* This must be the first member */
-	SMgrRelation srel;
-} SMgrSortArray;
-
 /* GUC variables */
 bool		zero_damaged_pages = false;
 int			bgwriter_lru_maxpages = 100;
@@ -2990,7 +2977,7 @@ DropRelFileNodesAllBuffers(RelFileNodeBackend *rnodes, int nnodes)
 	 * an exactly determined value, as it depends on many factors (CPU and RAM
 	 * speeds, amount of shared buffers etc.).
 	 */
-	use_bsearch = n > RELS_BSEARCH_THRESHOLD;
+	use_bsearch = n > DROP_RELS_BSEARCH_THRESHOLD;
 
 	/* sort the list of rnodes if necessary */
 	if (use_bsearch)
@@ -3240,104 +3227,6 @@ FlushRelationBuffers(Relation rel)
 	}
 }
 
-/* ---------------------------------------------------------------------
- *		FlushRelationsAllBuffers
- *
- *		This function flushes out of the buffer pool all the pages of all
- *		forks of the specified smgr relations.  It's equivalent to calling
- *		FlushRelationBuffers once per fork per relation.  The relations are
- *		assumed not to use local buffers.
- * --------------------------------------------------------------------
- */
-void
-FlushRelationsAllBuffers(SMgrRelation *smgrs, int nrels)
-{
-	int			i;
-	SMgrSortArray *srels;
-	bool		use_bsearch;
-
-	if (nrels == 0)
-		return;
-
-	/* fill-in array for qsort */
-	srels = palloc(sizeof(SMgrSortArray) * nrels);
-
-	for (i = 0; i < nrels; i++)
-	{
-		Assert(!RelFileNodeBackendIsTemp(smgrs[i]->smgr_rnode));
-
-		srels[i].rnode = smgrs[i]->smgr_rnode.node;
-		srels[i].srel = smgrs[i];
-	}
-
-	/*
-	 * Save the bsearch overhead for low number of relations to sync. See
-	 * DropRelFileNodesAllBuffers for details.
-	 */
-	use_bsearch = nrels > RELS_BSEARCH_THRESHOLD;
-
-	/* sort the list of SMgrRelations if necessary */
-	if (use_bsearch)
-		pg_qsort(srels, nrels, sizeof(SMgrSortArray), rnode_comparator);
-
-	/* Make sure we can handle the pin inside the loop */
-	ResourceOwnerEnlargeBuffers(CurrentResourceOwner);
-
-	for (i = 0; i < NBuffers; i++)
-	{
-		SMgrSortArray *srelent = NULL;
-		BufferDesc *bufHdr = GetBufferDescriptor(i);
-		uint32		buf_state;
-
-		/*
-		 * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
-		 * and saves some cycles.
-		 */
-
-		if (!use_bsearch)
-		{
-			int			j;
-
-			for (j = 0; j < nrels; j++)
-			{
-				if (RelFileNodeEquals(bufHdr->tag.rnode, srels[j].rnode))
-				{
-					srelent = &srels[j];
-					break;
-				}
-			}
-
-		}
-		else
-		{
-			srelent = bsearch((const void *) &(bufHdr->tag.rnode),
-							  srels, nrels, sizeof(SMgrSortArray),
-							  rnode_comparator);
-		}
-
-		/* buffer doesn't belong to any of the given relfilenodes; skip it */
-		if (srelent == NULL)
-			continue;
-
-		ReservePrivateRefCountEntry();
-
-		buf_state = LockBufHdr(bufHdr);
-		if (RelFileNodeEquals(bufHdr->tag.rnode, srelent->rnode) &&
-			(buf_state & (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
-		{
-			PinBuffer_Locked(bufHdr);
-			LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_SHARED);
-			FlushBuffer(bufHdr, srelent->srel);
-			LWLockRelease(BufferDescriptorGetContentLock(bufHdr));
-			UnpinBuffer(bufHdr, true);
-		}
-		else
-			UnlockBufHdr(bufHdr, buf_state);
-	}
-
-	pfree(srels);
-}
-
 /* ---------------------------------------------------------------------
  *		FlushDatabaseBuffers
  *
@@ -3539,15 +3428,13 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
 			(pg_atomic_read_u32(&bufHdr->state) & BM_PERMANENT))
 		{
 			/*
-			 * If we must not write WAL, due to a relfilenode-specific
+			 * If we're in recovery we cannot dirty a page because of a hint.
-			 * condition or being in recovery, don't dirty the page.  We can
+			 * We can set the hint, just not dirty the page as a result so the
-			 * set the hint, just not dirty the page as a result so the hint
+			 * hint is lost when we evict the page or shutdown.
-			 * is lost when we evict the page or shutdown.
 			 *
 			 * See src/backend/storage/page/README for longer discussion.
 			 */
-			if (RecoveryInProgress() ||
+			if (RecoveryInProgress())
-				RelFileNodeSkippingWAL(bufHdr->tag.rnode))
 				return;
 
 			/*

src/backend/storage/lmgr/lock.c

@@ -563,18 +563,6 @@ DoLockModesConflict(LOCKMODE mode1, LOCKMODE mode2)
 	return false;
 }
 
-#ifdef USE_ASSERT_CHECKING
-/*
- * GetLockMethodLocalHash -- return the hash of local locks, for modules that
- *		evaluate assertions based on all locks held.
- */
-HTAB *
-GetLockMethodLocalHash(void)
-{
-	return LockMethodLocalHash;
-}
-#endif
-
 /*
  * LockHasWaiters -- look up 'locktag' and check if releasing this
  *		lock would wake up other processes waiting for it.

src/backend/storage/smgr/md.c

@@ -359,10 +359,11 @@ mdcreate(SMgrRelation reln, ForkNumber forkNum, bool isRedo)
  * During replay, we would delete the file and then recreate it, which is fine
  * if the contents of the file were repopulated by subsequent WAL entries.
  * But if we didn't WAL-log insertions, but instead relied on fsyncing the
- * file after populating it (as we do at wal_level=minimal), the contents of
+ * file after populating it (as for instance CLUSTER and CREATE INDEX do),
- * the file would be lost forever.  By leaving the empty file until after the
+ * the contents of the file would be lost forever.  By leaving the empty file
- * next checkpoint, we prevent reassignment of the relfilenode number until
+ * until after the next checkpoint, we prevent reassignment of the relfilenode
- * it's safe, because relfilenode assignment skips over any existing file.
+ * number until it's safe, because relfilenode assignment skips over any
+ * existing file.
  *
  * We do not need to go through this dance for temp relations, though, because
  * we never make WAL entries for temp rels, and so a temp rel poses no threat
@@ -1018,19 +1019,12 @@ mdtruncate(SMgrRelation reln, ForkNumber forknum, BlockNumber nblocks)
  *	mdimmedsync() -- Immediately sync a relation to stable storage.
  *
  * Note that only writes already issued are synced; this routine knows
- * nothing of dirty buffers that may exist inside the buffer manager.  We
+ * nothing of dirty buffers that may exist inside the buffer manager.
- * sync active and inactive segments; smgrDoPendingSyncs() relies on this.
- * Consider a relation skipping WAL.  Suppose a checkpoint syncs blocks of
- * some segment, then mdtruncate() renders that segment inactive.  If we
- * crash before the next checkpoint syncs the newly-inactive segment, that
- * segment may survive recovery, reintroducing unwanted data into the table.
  */
 void
 mdimmedsync(SMgrRelation reln, ForkNumber forknum)
 {
 	MdfdVec    *v;
-	BlockNumber segno = 0;
-	bool		active = true;
 
 	/*
 	 * NOTE: mdnblocks makes sure we have opened all active segments, so that
@@ -1040,42 +1034,14 @@ mdimmedsync(SMgrRelation reln, ForkNumber forknum)
 
 	v = mdopen(reln, forknum, EXTENSION_FAIL);
 
-	/*
-	 * Temporarily open inactive segments, then close them after sync.  There
-	 * may be some inactive segments left opened after fsync() error, but that
-	 * is harmless.  We don't bother to clean them up and take a risk of
-	 * further trouble.  The next mdclose() will soon close them.
-	 */
 	while (v != NULL)
 	{
-		File		vfd = v->mdfd_vfd;
+		if (FileSync(v->mdfd_vfd) < 0)
-
-		if (active)
-			v = v->mdfd_chain;
-		else
-		{
-			Assert(v->mdfd_chain == NULL);
-			pfree(v);
-			v = NULL;
-		}
-
-		if (FileSync(vfd) < 0)
 			ereport(data_sync_elevel(ERROR),
 					(errcode_for_file_access(),
 					 errmsg("could not fsync file \"%s\": %m",
-							FilePathName(vfd))));
+							FilePathName(v->mdfd_vfd))));
-
+		v = v->mdfd_chain;
-		/* Close inactive segments immediately */
-		if (!active)
-			FileClose(vfd);
-
-		segno++;
-
-		if (v == NULL)
-		{
-			v = _mdfd_openseg(reln, forknum, segno, 0);
-			active = false;
-		}
 	}
 }
 

src/backend/storage/smgr/smgr.c

@@ -408,41 +408,6 @@ smgrdounlink(SMgrRelation reln, bool isRedo)
 	(*(smgrsw[which].smgr_unlink)) (rnode, InvalidForkNumber, isRedo);
 }
 
-/*
- *	smgrdosyncall() -- Immediately sync all forks of all given relations
- *
- *		All forks of all given relations are synced out to the store.
- *
- *		This is equivalent to FlushRelationBuffers() for each smgr relation,
- *		then calling smgrimmedsync() for all forks of each relation, but it's
- *		significantly quicker so should be preferred when possible.
- */
-void
-smgrdosyncall(SMgrRelation *rels, int nrels)
-{
-	int			i = 0;
-	ForkNumber	forknum;
-
-	if (nrels == 0)
-		return;
-
-	FlushRelationsAllBuffers(rels, nrels);
-
-	/*
-	 * Sync the physical file(s).
-	 */
-	for (i = 0; i < nrels; i++)
-	{
-		int			which = rels[i]->smgr_which;
-
-		for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
-		{
-			if (smgrsw[which].smgr_exists(rels[i], forknum))
-				smgrsw[which].smgr_immedsync(rels[i], forknum);
-		}
-	}
-}
-
 /*
  *	smgrdounlinkall() -- Immediately unlink all forks of all given relations
  *

src/backend/utils/cache/relcache.c

@@ -244,9 +244,6 @@ static void RelationReloadIndexInfo(Relation relation);
 static void RelationReloadNailed(Relation relation);
 static void RelationFlushRelation(Relation relation);
 static void RememberToFreeTupleDescAtEOX(TupleDesc td);
-#ifdef USE_ASSERT_CHECKING
-static void AssertPendingSyncConsistency(Relation relation);
-#endif
 static void AtEOXact_cleanup(Relation relation, bool isCommit);
 static void AtEOSubXact_cleanup(Relation relation, bool isCommit,
 					SubTransactionId mySubid, SubTransactionId parentSubid);
@@ -984,8 +981,6 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
 	relation->rd_isnailed = false;
 	relation->rd_createSubid = InvalidSubTransactionId;
 	relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
-	relation->rd_firstRelfilenodeSubid = InvalidSubTransactionId;
-	relation->rd_droppedSubid = InvalidSubTransactionId;
 	switch (relation->rd_rel->relpersistence)
 	{
 		case RELPERSISTENCE_UNLOGGED:
@@ -1609,8 +1604,6 @@ formrdesc(const char *relationName, Oid relationReltype,
 	relation->rd_isnailed = true;
 	relation->rd_createSubid = InvalidSubTransactionId;
 	relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
-	relation->rd_firstRelfilenodeSubid = InvalidSubTransactionId;
-	relation->rd_droppedSubid = InvalidSubTransactionId;
 	relation->rd_backend = InvalidBackendId;
 	relation->rd_islocaltemp = false;
 
@@ -1777,13 +1770,6 @@ RelationIdGetRelation(Oid relationId)
 
 	if (RelationIsValid(rd))
 	{
-		/* return NULL for dropped relations */
-		if (rd->rd_droppedSubid != InvalidSubTransactionId)
-		{
-			Assert(!rd->rd_isvalid);
-			return NULL;
-		}
-
 		RelationIncrementReferenceCount(rd);
 		/* revalidate cache entry if necessary */
 		if (!rd->rd_isvalid)
@@ -1876,7 +1862,7 @@ RelationClose(Relation relation)
 #ifdef RELCACHE_FORCE_RELEASE
 	if (RelationHasReferenceCountZero(relation) &&
 		relation->rd_createSubid == InvalidSubTransactionId &&
-		relation->rd_firstRelfilenodeSubid == InvalidSubTransactionId)
+		relation->rd_newRelfilenodeSubid == InvalidSubTransactionId)
 		RelationClearRelation(relation, false);
 #endif
 }
@@ -1915,10 +1901,9 @@ RelationReloadIndexInfo(Relation relation)
 	HeapTuple	pg_class_tuple;
 	Form_pg_class relp;
 
-	/* Should be called only for invalidated, live indexes */
+	/* Should be called only for invalidated indexes */
 	Assert(relation->rd_rel->relkind == RELKIND_INDEX &&
-		   !relation->rd_isvalid &&
+		   !relation->rd_isvalid);
-		   relation->rd_droppedSubid == InvalidSubTransactionId);
 
 	/* Ensure it's closed at smgr level */
 	RelationCloseSmgr(relation);
@@ -2198,13 +2183,6 @@ RelationClearRelation(Relation relation, bool rebuild)
 		return;
 	}
 
-	/* Mark it invalid until we've finished rebuild */
-	relation->rd_isvalid = false;
-
-	/* See RelationForgetRelation(). */
-	if (relation->rd_droppedSubid != InvalidSubTransactionId)
-		return;
-
 	/*
 	 * Even non-system indexes should not be blown away if they are open and
 	 * have valid index support information.  This avoids problems with active
@@ -2216,11 +2194,15 @@ RelationClearRelation(Relation relation, bool rebuild)
 		relation->rd_refcnt > 0 &&
 		relation->rd_indexcxt != NULL)
 	{
+		relation->rd_isvalid = false;	/* needs to be revalidated */
 		if (IsTransactionState())
 			RelationReloadIndexInfo(relation);
 		return;
 	}
 
+	/* Mark it invalid until we've finished rebuild */
+	relation->rd_isvalid = false;
+
 	/*
 	 * If we're really done with the relcache entry, blow it away. But if
 	 * someone is still using it, reconstruct the whole deal without moving
@@ -2278,12 +2260,12 @@ RelationClearRelation(Relation relation, bool rebuild)
 		 * problem.
 		 *
 		 * When rebuilding an open relcache entry, we must preserve ref count,
-		 * rd_*Subid, and rd_toastoid state.  Also attempt to preserve the
+		 * rd_createSubid/rd_newRelfilenodeSubid, and rd_toastoid state.  Also
-		 * pg_class entry (rd_rel), tupledesc, and rewrite-rule substructures
+		 * attempt to preserve the pg_class entry (rd_rel), tupledesc, and
-		 * in place, because various places assume that these structures won't
+		 * rewrite-rule substructures in place, because various places assume
-		 * move while they are working with an open relcache entry.  (Note:
+		 * that these structures won't move while they are working with an
-		 * the refcount mechanism for tupledescs might someday allow us to
+		 * open relcache entry.  (Note: the refcount mechanism for tupledescs
-		 * remove this hack for the tupledesc.)
+		 * might someday allow us to remove this hack for the tupledesc.)
 		 *
 		 * Note that this process does not touch CurrentResourceOwner; which
 		 * is good because whatever ref counts the entry may have do not
@@ -2360,8 +2342,6 @@ RelationClearRelation(Relation relation, bool rebuild)
 		/* creation sub-XIDs must be preserved */
 		SWAPFIELD(SubTransactionId, rd_createSubid);
 		SWAPFIELD(SubTransactionId, rd_newRelfilenodeSubid);
-		SWAPFIELD(SubTransactionId, rd_firstRelfilenodeSubid);
-		SWAPFIELD(SubTransactionId, rd_droppedSubid);
 		/* un-swap rd_rel pointers, swap contents instead */
 		SWAPFIELD(Form_pg_class, rd_rel);
 		/* ... but actually, we don't have to update newrel->rd_rel */
@@ -2398,12 +2378,12 @@ static void
 RelationFlushRelation(Relation relation)
 {
 	if (relation->rd_createSubid != InvalidSubTransactionId ||
-		relation->rd_firstRelfilenodeSubid != InvalidSubTransactionId)
+		relation->rd_newRelfilenodeSubid != InvalidSubTransactionId)
 	{
 		/*
 		 * New relcache entries are always rebuilt, not flushed; else we'd
-		 * forget the "new" status of the relation.  Ditto for the
+		 * forget the "new" status of the relation, which is a useful
-		 * new-relfilenode status.
+		 * optimization to have.  Ditto for the new-relfilenode status.
 		 *
 		 * The rel could have zero refcnt here, so temporarily increment the
 		 * refcnt to ensure it's safe to rebuild it.  We can assume that the
@@ -2425,7 +2405,10 @@ RelationFlushRelation(Relation relation)
 }
 
 /*
- * RelationForgetRelation - caller reports that it dropped the relation
+ * RelationForgetRelation - unconditionally remove a relcache entry
+ *
+ *		   External interface for destroying a relcache entry when we
+ *		   drop the relation.
  */
 void
 RelationForgetRelation(Oid rid)
@@ -2440,19 +2423,7 @@ RelationForgetRelation(Oid rid)
 	if (!RelationHasReferenceCountZero(relation))
 		elog(ERROR, "relation %u is still open", rid);
 
-	Assert(relation->rd_droppedSubid == InvalidSubTransactionId);
+	/* Unconditionally destroy the relcache entry */
-	if (relation->rd_createSubid != InvalidSubTransactionId ||
-		relation->rd_firstRelfilenodeSubid != InvalidSubTransactionId)
-	{
-		/*
-		 * In the event of subtransaction rollback, we must not forget
-		 * rd_*Subid.  Mark the entry "dropped" so RelationClearRelation()
-		 * invalidates it in lieu of destroying it.  (If we're in a top
-		 * transaction, we could opt to destroy the entry.)
-		 */
-		relation->rd_droppedSubid = GetCurrentSubTransactionId();
-	}
-
 	RelationClearRelation(relation, false);
 }
 
@@ -2492,10 +2463,11 @@ RelationCacheInvalidateEntry(Oid relationId)
  *	 relation cache and re-read relation mapping data.
  *
  *	 This is currently used only to recover from SI message buffer overflow,
- *	 so we do not touch relations having new-in-transaction relfilenodes; they
+ *	 so we do not touch new-in-transaction relations; they cannot be targets
- *	 cannot be targets of cross-backend SI updates (and our own updates now go
+ *	 of cross-backend SI updates (and our own updates now go through a
- *	 through a separate linked list that isn't limited by the SI message
+ *	 separate linked list that isn't limited by the SI message buffer size).
- *	 buffer size).
+ *	 Likewise, we need not discard new-relfilenode-in-transaction hints,
+ *	 since any invalidation of those would be a local event.
  *
  *	 We do this in two phases: the first pass deletes deletable items, and
  *	 the second one rebuilds the rebuildable items.  This is essential for
@@ -2546,7 +2518,7 @@ RelationCacheInvalidate(void)
 		 * pending invalidations.
 		 */
 		if (relation->rd_createSubid != InvalidSubTransactionId ||
-			relation->rd_firstRelfilenodeSubid != InvalidSubTransactionId)
+			relation->rd_newRelfilenodeSubid != InvalidSubTransactionId)
 			continue;
 
 		relcacheInvalsReceived++;
@@ -2658,96 +2630,6 @@ RememberToFreeTupleDescAtEOX(TupleDesc td)
 	EOXactTupleDescArray[NextEOXactTupleDescNum++] = td;
 }
 
-#ifdef USE_ASSERT_CHECKING
-/*
- * Relation kinds that have physical storage. These relations normally have
- * relfilenode set to non-zero, but it can also be zero if the relation is
- * mapped.
- */
-#define RELKIND_HAS_STORAGE(relkind) \
-	((relkind) == RELKIND_RELATION || \
-	 (relkind) == RELKIND_INDEX || \
-	 (relkind) == RELKIND_SEQUENCE || \
-	 (relkind) == RELKIND_TOASTVALUE || \
-	 (relkind) == RELKIND_MATVIEW)
-
-static void
-AssertPendingSyncConsistency(Relation relation)
-{
-	bool		relcache_verdict =
-	relation->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT &&
-	((relation->rd_createSubid != InvalidSubTransactionId &&
-	  RELKIND_HAS_STORAGE(relation->rd_rel->relkind)) ||
-	 relation->rd_firstRelfilenodeSubid != InvalidSubTransactionId);
-
-	Assert(relcache_verdict == RelFileNodeSkippingWAL(relation->rd_node));
-
-	if (relation->rd_droppedSubid != InvalidSubTransactionId)
-		Assert(!relation->rd_isvalid &&
-			   (relation->rd_createSubid != InvalidSubTransactionId ||
-				relation->rd_firstRelfilenodeSubid != InvalidSubTransactionId));
-}
-
-/*
- * AssertPendingSyncs_RelationCache
- *
- *	Assert that relcache.c and storage.c agree on whether to skip WAL.
- */
-void
-AssertPendingSyncs_RelationCache(void)
-{
-	HASH_SEQ_STATUS status;
-	LOCALLOCK  *locallock;
-	Relation   *rels;
-	int			maxrels;
-	int			nrels;
-	RelIdCacheEnt *idhentry;
-	int			i;
-
-	/*
-	 * Open every relation that this transaction has locked.  If, for some
-	 * relation, storage.c is skipping WAL and relcache.c is not skipping WAL,
-	 * a CommandCounterIncrement() typically yields a local invalidation
-	 * message that destroys the relcache entry.  By recreating such entries
-	 * here, we detect the problem.
-	 */
-	PushActiveSnapshot(GetTransactionSnapshot());
-	maxrels = 1;
-	rels = palloc(maxrels * sizeof(*rels));
-	nrels = 0;
-	hash_seq_init(&status, GetLockMethodLocalHash());
-	while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
-	{
-		Oid			relid;
-		Relation	r;
-
-		if (locallock->nLocks <= 0)
-			continue;
-		if ((LockTagType) locallock->tag.lock.locktag_type !=
-			LOCKTAG_RELATION)
-			continue;
-		relid = ObjectIdGetDatum(locallock->tag.lock.locktag_field2);
-		r = RelationIdGetRelation(relid);
-		if (!RelationIsValid(r))
-			continue;
-		if (nrels >= maxrels)
-		{
-			maxrels *= 2;
-			rels = repalloc(rels, maxrels * sizeof(*rels));
-		}
-		rels[nrels++] = r;
-	}
-
-	hash_seq_init(&status, RelationIdCache);
-	while ((idhentry = (RelIdCacheEnt *) hash_seq_search(&status)) != NULL)
-		AssertPendingSyncConsistency(idhentry->reldesc);
-
-	for (i = 0; i < nrels; i++)
-		RelationClose(rels[i]);
-	PopActiveSnapshot();
-}
-#endif
-
 /*
  * AtEOXact_RelationCache
  *
@@ -2830,8 +2712,6 @@ AtEOXact_RelationCache(bool isCommit)
 static void
 AtEOXact_cleanup(Relation relation, bool isCommit)
 {
-	bool		clear_relcache = false;
-
 	/*
 	 * The relcache entry's ref count should be back to its normal
 	 * not-in-a-transaction state: 0 unless it's nailed in cache.
@@ -2857,31 +2737,17 @@ AtEOXact_cleanup(Relation relation, bool isCommit)
 #endif
 
 	/*
-	 * Is the relation live after this transaction ends?
+	 * Is it a relation created in the current transaction?
 	 *
-	 * During commit, clear the relcache entry if it is preserved after
+	 * During commit, reset the flag to zero, since we are now out of the
-	 * relation drop, in order not to orphan the entry.  During rollback,
+	 * creating transaction.  During abort, simply delete the relcache entry
-	 * clear the relcache entry if the relation is created in the current
+	 * --- it isn't interesting any longer.
-	 * transaction since it isn't interesting any longer once we are out of
-	 * the transaction.
 	 */
-	clear_relcache =
+	if (relation->rd_createSubid != InvalidSubTransactionId)
-		(isCommit ?
-		 relation->rd_droppedSubid != InvalidSubTransactionId :
-		 relation->rd_createSubid != InvalidSubTransactionId);
-
-	/*
-	 * Since we are now out of the transaction, reset the subids to zero.
-	 * That also lets RelationClearRelation() drop the relcache entry.
-	 */
-	relation->rd_createSubid = InvalidSubTransactionId;
-	relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
-	relation->rd_firstRelfilenodeSubid = InvalidSubTransactionId;
-	relation->rd_droppedSubid = InvalidSubTransactionId;
-
-	if (clear_relcache)
 	{
-		if (RelationHasReferenceCountZero(relation))
+		if (isCommit)
+			relation->rd_createSubid = InvalidSubTransactionId;
+		else if (RelationHasReferenceCountZero(relation))
 		{
 			RelationClearRelation(relation, false);
 			return;
@@ -2896,11 +2762,17 @@ AtEOXact_cleanup(Relation relation, bool isCommit)
 			 * eventually.  This must be just a WARNING to avoid
 			 * error-during-error-recovery loops.
 			 */
+			relation->rd_createSubid = InvalidSubTransactionId;
 			elog(WARNING, "cannot remove relcache entry for \"%s\" because it has nonzero refcount",
 				 RelationGetRelationName(relation));
 		}
 	}
 
+	/*
+	 * Likewise, reset the hint about the relfilenode being new.
+	 */
+	relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
+
 	/*
 	 * Flush any temporary index list.
 	 */
@@ -2975,28 +2847,15 @@ AtEOSubXact_cleanup(Relation relation, bool isCommit,
 	/*
 	 * Is it a relation created in the current subtransaction?
 	 *
-	 * During subcommit, mark it as belonging to the parent, instead, as long
+	 * During subcommit, mark it as belonging to the parent, instead. During
-	 * as it has not been dropped. Otherwise simply delete the relcache entry.
+	 * subabort, simply delete the relcache entry.
-	 * --- it isn't interesting any longer.
 	 */
 	if (relation->rd_createSubid == mySubid)
 	{
-		/*
+		if (isCommit)
-		 * Valid rd_droppedSubid means the corresponding relation is dropped
-		 * but the relcache entry is preserved for at-commit pending sync. We
-		 * need to drop it explicitly here not to make the entry orphan.
-		 */
-		Assert(relation->rd_droppedSubid == mySubid ||
-			   relation->rd_droppedSubid == InvalidSubTransactionId);
-		if (isCommit && relation->rd_droppedSubid == InvalidSubTransactionId)
 			relation->rd_createSubid = parentSubid;
 		else if (RelationHasReferenceCountZero(relation))
 		{
-			/* allow the entry to be removed */
-			relation->rd_createSubid = InvalidSubTransactionId;
-			relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
-			relation->rd_firstRelfilenodeSubid = InvalidSubTransactionId;
-			relation->rd_droppedSubid = InvalidSubTransactionId;
 			RelationClearRelation(relation, false);
 			return;
 		}
@@ -3016,8 +2875,7 @@ AtEOSubXact_cleanup(Relation relation, bool isCommit,
 	}
 
 	/*
-	 * Likewise, update or drop any new-relfilenode-in-subtransaction record
+	 * Likewise, update or drop any new-relfilenode-in-subtransaction hint.
-	 * or drop record.
 	 */
 	if (relation->rd_newRelfilenodeSubid == mySubid)
 	{
@@ -3027,22 +2885,6 @@ AtEOSubXact_cleanup(Relation relation, bool isCommit,
 			relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
 	}
 
-	if (relation->rd_firstRelfilenodeSubid == mySubid)
-	{
-		if (isCommit)
-			relation->rd_firstRelfilenodeSubid = parentSubid;
-		else
-			relation->rd_firstRelfilenodeSubid = InvalidSubTransactionId;
-	}
-
-	if (relation->rd_droppedSubid == mySubid)
-	{
-		if (isCommit)
-			relation->rd_droppedSubid = parentSubid;
-		else
-			relation->rd_droppedSubid = InvalidSubTransactionId;
-	}
-
 	/*
 	 * Flush any temporary index list.
 	 */
@@ -3142,7 +2984,6 @@ RelationBuildLocalRelation(const char *relname,
 	/* it's being created in this transaction */
 	rel->rd_createSubid = GetCurrentSubTransactionId();
 	rel->rd_newRelfilenodeSubid = InvalidSubTransactionId;
-	rel->rd_firstRelfilenodeSubid = InvalidSubTransactionId;
 
 	/*
 	 * create a new tuple descriptor from the one passed in.  We do this
@@ -3413,29 +3254,14 @@ RelationSetNewRelfilenode(Relation relation, char persistence,
 	 */
 	CommandCounterIncrement();
 
-	RelationAssumeNewRelfilenode(relation);
-}
-
 	/*
- * RelationAssumeNewRelfilenode
+	 * Mark the rel as having been given a new relfilenode in the current
- *
+	 * (sub) transaction.  This is a hint that can be used to optimize later
- * Code that modifies pg_class.reltablespace or pg_class.relfilenode must call
+	 * operations on the rel in the same transaction.
- * this.  The call shall precede any code that might insert WAL records whose
- * replay would modify bytes in the new RelFileNode, and the call shall follow
- * any WAL modifying bytes in the prior RelFileNode.  See struct RelationData.
- * Ideally, call this as near as possible to the CommandCounterIncrement()
- * that makes the pg_class change visible (before it or after it); that
- * minimizes the chance of future development adding a forbidden WAL insertion
- * between RelationAssumeNewRelfilenode() and CommandCounterIncrement().
 	 */
-void
-RelationAssumeNewRelfilenode(Relation relation)
-{
 	relation->rd_newRelfilenodeSubid = GetCurrentSubTransactionId();
-	if (relation->rd_firstRelfilenodeSubid == InvalidSubTransactionId)
-		relation->rd_firstRelfilenodeSubid = relation->rd_newRelfilenodeSubid;
 
-	/* Flag relation as needing eoxact cleanup (to clear these fields) */
+	/* Flag relation as needing eoxact cleanup (to remove the hint) */
 	EOXactListAdd(relation);
 }
 
@@ -5434,8 +5260,6 @@ load_relcache_init_file(bool shared)
 		rel->rd_idattr = NULL;
 		rel->rd_createSubid = InvalidSubTransactionId;
 		rel->rd_newRelfilenodeSubid = InvalidSubTransactionId;
-		rel->rd_firstRelfilenodeSubid = InvalidSubTransactionId;
-		rel->rd_droppedSubid = InvalidSubTransactionId;
 		rel->rd_amcache = NULL;
 		MemSet(&rel->pgstat_info, 0, sizeof(rel->pgstat_info));
 

src/backend/utils/misc/guc.c

@@ -32,7 +32,6 @@
 #include "access/twophase.h"
 #include "access/xact.h"
 #include "catalog/namespace.h"
-#include "catalog/storage.h"
 #include "commands/async.h"
 #include "commands/prepare.h"
 #include "commands/vacuum.h"
@@ -2323,17 +2322,6 @@ static struct config_int ConfigureNamesInt[] =
 		NULL, NULL, NULL
 	},
 
-	{
-		{"wal_skip_threshold", PGC_USERSET, WAL_SETTINGS,
-			gettext_noop("Size of new file to fsync instead of writing WAL."),
-			NULL,
-			GUC_UNIT_KB
-		},
-		&wal_skip_threshold,
-		2048, 0, MAX_KILOBYTES,
-		NULL, NULL, NULL
-	},
-
 	{
 		/* see max_connections */
 		{"max_wal_senders", PGC_POSTMASTER, REPLICATION_SENDING,

src/backend/utils/misc/postgresql.conf.sample

@@ -197,7 +197,6 @@
 					# (change requires restart)
 #wal_writer_delay = 200ms		# 1-10000 milliseconds
 #wal_writer_flush_after = 1MB		# measured in pages, 0 disables
-#wal_skip_threshold = 2MB
 
 #commit_delay = 0			# range 0-100000, in microseconds
 #commit_siblings = 5			# range 1-1000

src/include/access/gist_private.h

@@ -189,7 +189,6 @@ typedef GISTScanOpaqueData *GISTScanOpaque;
  /* #define XLOG_GIST_INSERT_COMPLETE	 0x40 */	/* not used anymore */
 #define XLOG_GIST_CREATE_INDEX		0x50
  /* #define XLOG_GIST_PAGE_DELETE		 0x60 */	/* not used anymore */
-#define XLOG_GIST_ASSIGN_LSN		0x70	/* nop, assign new LSN */
 
 /*
  * Backup Blk 0: updated page.
@@ -478,8 +477,6 @@ extern XLogRecPtr gistXLogSplit(bool page_is_leaf,
 			  BlockNumber origrlink, GistNSN oldnsn,
 			  Buffer leftchild, bool markfollowright);
 
-extern XLogRecPtr gistXLogAssignLSN(void);
-
 /* gistget.c */
 extern bool gistgettuple(IndexScanDesc scan, ScanDirection dir);
 extern int64 gistgetbitmap(IndexScanDesc scan, TIDBitmap *tbm);

src/include/access/heapam.h

@@ -25,6 +25,7 @@
 
 
 /* "options" flag bits for heap_insert */
+#define HEAP_INSERT_SKIP_WAL	0x0001
 #define HEAP_INSERT_SKIP_FSM	0x0002
 #define HEAP_INSERT_FROZEN		0x0004
 #define HEAP_INSERT_SPECULATIVE 0x0008

src/include/access/rewriteheap.h

@@ -23,7 +23,7 @@ typedef struct RewriteStateData *RewriteState;
 
 extern RewriteState begin_heap_rewrite(Relation OldHeap, Relation NewHeap,
 				   TransactionId OldestXmin, TransactionId FreezeXid,
-				   MultiXactId MultiXactCutoff);
+				   MultiXactId MultiXactCutoff, bool use_wal);
 extern void end_heap_rewrite(RewriteState state);
 extern void rewrite_heap_tuple(RewriteState state, HeapTuple oldTuple,
 				   HeapTuple newTuple);

src/include/catalog/storage.h

@@ -18,22 +18,16 @@
 #include "storage/relfilenode.h"
 #include "utils/relcache.h"
 
-/* GUC variables */
-extern int	wal_skip_threshold;
-
 extern void RelationCreateStorage(RelFileNode rnode, char relpersistence);
 extern void RelationDropStorage(Relation rel);
 extern void RelationPreserveStorage(RelFileNode rnode, bool atCommit);
-extern void RelationPreTruncate(Relation rel);
 extern void RelationTruncate(Relation rel, BlockNumber nblocks);
-extern bool RelFileNodeSkippingWAL(RelFileNode rnode);
 
 /*
  * These functions used to be in storage/smgr/smgr.c, which explains the
  * naming
  */
 extern void smgrDoPendingDeletes(bool isCommit);
-extern void smgrDoPendingSyncs(bool isCommit);
 extern int	smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr);
 extern void AtSubCommit_smgr(void);
 extern void AtSubAbort_smgr(void);

src/include/nodes/parsenodes.h

@@ -2454,9 +2454,6 @@ typedef struct IndexStmt
 	bool		transformed;	/* true when transformIndexStmt is finished */
 	bool		concurrent;		/* should this be a concurrent index build? */
 	bool		if_not_exists;	/* just do nothing if index already exists? */
-	SubTransactionId oldCreateSubid;	/* rd_createSubid of oldNode */
-	SubTransactionId oldFirstRelfilenodeSubid;	/* rd_firstRelfilenodeSubid of
-												 * oldNode */
 } IndexStmt;
 
 /* ----------------------

src/include/storage/bufmgr.h

@@ -50,9 +50,6 @@ typedef enum
 /* forward declared, to avoid having to expose buf_internals.h here */
 struct WritebackContext;
 
-/* forward declared, to avoid including smgr.h here */
-struct SMgrRelationData;
-
 /* in globals.c ... this duplicates miscadmin.h */
 extern PGDLLIMPORT int NBuffers;
 
@@ -193,7 +190,6 @@ extern BlockNumber RelationGetNumberOfBlocksInFork(Relation relation,
 								ForkNumber forkNum);
 extern void FlushOneBuffer(Buffer buffer);
 extern void FlushRelationBuffers(Relation rel);
-extern void FlushRelationsAllBuffers(struct SMgrRelationData **smgrs, int nrels);
 extern void FlushDatabaseBuffers(Oid dbid);
 extern void DropRelFileNodeBuffers(RelFileNodeBackend rnode,
 					   ForkNumber forkNum, BlockNumber firstDelBlock);

src/include/storage/lock.h

@@ -541,9 +541,6 @@ extern void LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks);
 extern void LockReleaseSession(LOCKMETHODID lockmethodid);
 extern void LockReleaseCurrentOwner(LOCALLOCK **locallocks, int nlocks);
 extern void LockReassignCurrentOwner(LOCALLOCK **locallocks, int nlocks);
-#ifdef USE_ASSERT_CHECKING
-extern HTAB *GetLockMethodLocalHash(void);
-#endif
 extern bool LockHasWaiters(const LOCKTAG *locktag,
 			   LOCKMODE lockmode, bool sessionLock);
 extern VirtualTransactionId *GetLockConflicts(const LOCKTAG *locktag,

src/include/storage/smgr.h

@@ -87,7 +87,6 @@ extern void smgrcloseall(void);
 extern void smgrclosenode(RelFileNodeBackend rnode);
 extern void smgrcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo);
 extern void smgrdounlink(SMgrRelation reln, bool isRedo);
-extern void smgrdosyncall(SMgrRelation *rels, int nrels);
 extern void smgrdounlinkall(SMgrRelation *rels, int nrels, bool isRedo);
 extern void smgrdounlinkfork(SMgrRelation reln, ForkNumber forknum, bool isRedo);
 extern void smgrextend(SMgrRelation reln, ForkNumber forknum,

src/include/utils/rel.h

@@ -65,43 +65,25 @@ typedef struct RelationData
 
 	/*----------
 	 * rd_createSubid is the ID of the highest subtransaction the rel has
-	 * survived into or zero if the rel or its rd_node was created before the
+	 * survived into; or zero if the rel was not created in the current top
-	 * current top transaction.  (IndexStmt.oldNode leads to the case of a new
+	 * transaction.  This can be now be relied on, whereas previously it could
-	 * rel with an old rd_node.)  rd_firstRelfilenodeSubid is the ID of the
+	 * be "forgotten" in earlier releases. Likewise, rd_newRelfilenodeSubid is
-	 * highest subtransaction an rd_node change has survived into or zero if
+	 * the ID of the highest subtransaction the relfilenode change has
-	 * rd_node matches the value it had at the start of the current top
+	 * survived into, or zero if not changed in the current transaction (or we
-	 * transaction.  (Rolling back the subtransaction that
+	 * have forgotten changing it). rd_newRelfilenodeSubid can be forgotten
-	 * rd_firstRelfilenodeSubid denotes would restore rd_node to the value it
+	 * when a relation has multiple new relfilenodes within a single
-	 * had at the start of the current top transaction.  Rolling back any
+	 * transaction, with one of them occurring in a subsequently aborted
-	 * lower subtransaction would not.)  Their accuracy is critical to
+	 * subtransaction, e.g.
-	 * RelationNeedsWAL().
-	 *
-	 * rd_newRelfilenodeSubid is the ID of the highest subtransaction the
-	 * most-recent relfilenode change has survived into or zero if not changed
-	 * in the current transaction (or we have forgotten changing it).  This
-	 * field is accurate when non-zero, but it can be zero when a relation has
-	 * multiple new relfilenodes within a single transaction, with one of them
-	 * occurring in a subsequently aborted subtransaction, e.g.
 	 *		BEGIN;
 	 *		TRUNCATE t;
 	 *		SAVEPOINT save;
 	 *		TRUNCATE t;
 	 *		ROLLBACK TO save;
 	 *		-- rd_newRelfilenodeSubid is now forgotten
-	 *
-	 * If every rd_*Subid field is zero, they are read-only outside
-	 * relcache.c.  Files that trigger rd_node changes by updating
-	 * pg_class.reltablespace and/or pg_class.relfilenode call
-	 * RelationAssumeNewRelfilenode() to update rd_*Subid.
-	 *
-	 * rd_droppedSubid is the ID of the highest subtransaction that a drop of
-	 * the rel has survived into.  In entries visible outside relcache.c, this
-	 * is always zero.
 	 */
 	SubTransactionId rd_createSubid;	/* rel was created in current xact */
-	SubTransactionId rd_newRelfilenodeSubid;	/* highest subxact changing
+	SubTransactionId rd_newRelfilenodeSubid;	/* new relfilenode assigned in
-												 * rd_node to current value */
+												 * current xact */
-	/* see end for rd_firstRelfilenodeSubid and rd_droppedSubid */
 
 	Form_pg_class rd_rel;		/* RELATION tuple */
 	TupleDesc	rd_att;			/* tuple descriptor */
@@ -195,10 +177,6 @@ typedef struct RelationData
 
 	/* use "struct" here to avoid needing to include pgstat.h: */
 	struct PgStat_TableStatus *pgstat_info;		/* statistics collection area */
-
-	SubTransactionId rd_firstRelfilenodeSubid;	/* highest subxact changing
-												 * rd_node to any value */
-	SubTransactionId rd_droppedSubid;	/* dropped with another Subid set */
 } RelationData;
 
 
@@ -485,16 +463,9 @@ typedef struct ViewOptions
 /*
  * RelationNeedsWAL
  *		True if relation needs WAL.
- *
- * Returns false if wal_level = minimal and this relation is created or
- * truncated in the current transaction.  See "Skipping WAL for New
- * RelFileNode" in src/backend/access/transam/README.
  */
 #define RelationNeedsWAL(relation) \
-	((relation)->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT &&	\
+	((relation)->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT)
-	 (XLogIsNeeded() ||													\
-	  (relation->rd_createSubid == InvalidSubTransactionId &&			\
-	   relation->rd_firstRelfilenodeSubid == InvalidSubTransactionId)))
 
 /*
  * RelationUsesLocalBuffers

src/include/utils/relcache.h

@@ -95,11 +95,10 @@ extern Relation RelationBuildLocalRelation(const char *relname,
 						   char relkind);
 
 /*
- * Routines to manage assignment of new relfilenode to a relation
+ * Routine to manage assignment of new relfilenode to a relation
  */
 extern void RelationSetNewRelfilenode(Relation relation, char persistence,
 						  TransactionId freezeXid, MultiXactId minmulti);
-extern void RelationAssumeNewRelfilenode(Relation relation);
 
 /*
  * Routines for flushing/rebuilding relcache entries in various scenarios
@@ -112,11 +111,6 @@ extern void RelationCacheInvalidate(void);
 
 extern void RelationCloseSmgrByOid(Oid relationId);
 
-#ifdef USE_ASSERT_CHECKING
-extern void AssertPendingSyncs_RelationCache(void);
-#else
-#define AssertPendingSyncs_RelationCache() do {} while (0)
-#endif
 extern void AtEOXact_RelationCache(bool isCommit);
 extern void AtEOSubXact_RelationCache(bool isCommit, SubTransactionId mySubid,
 						  SubTransactionId parentSubid);

src/test/recovery/t/018_wal_optimize.pl

@@ -1,372 +0,0 @@
-# Test WAL replay when some operation has skipped WAL.
-#
-# These tests exercise code that once violated the mandate described in
-# src/backend/access/transam/README section "Skipping WAL for New
-# RelFileNode".  The tests work by committing some transactions, initiating an
-# immediate shutdown, and confirming that the expected data survives recovery.
-# For many years, individual commands made the decision to skip WAL, hence the
-# frequent appearance of COPY in these tests.
-use strict;
-use warnings;
-
-use PostgresNode;
-use TestLib;
-use Test::More tests => 34;
-
-sub check_orphan_relfilenodes
-{
-	my ($node, $test_name) = @_;
-
-	my $db_oid = $node->safe_psql('postgres',
-		"SELECT oid FROM pg_database WHERE datname = 'postgres'");
-	my $prefix               = "base/$db_oid/";
-	my $filepaths_referenced = $node->safe_psql(
-		'postgres', "
-	   SELECT pg_relation_filepath(oid) FROM pg_class
-	   WHERE reltablespace = 0 AND relpersistence <> 't' AND
-	   pg_relation_filepath(oid) IS NOT NULL;");
-	is_deeply(
-		[
-			sort(map { "$prefix$_" }
-				  grep(/^[0-9]+$/, slurp_dir($node->data_dir . "/$prefix")))
-		],
-		[ sort split /\n/, $filepaths_referenced ],
-		$test_name);
-	return;
-}
-
-# We run this same test suite for both wal_level=minimal and replica.
-sub run_wal_optimize
-{
-	my $wal_level = shift;
-
-	my $node = get_new_node("node_$wal_level");
-	$node->init;
-	$node->append_conf(
-		'postgresql.conf', qq(
-wal_level = $wal_level
-max_prepared_transactions = 1
-wal_log_hints = on
-wal_skip_threshold = 0
-#wal_debug = on
-));
-	$node->start;
-
-	# Setup
-	my $tablespace_dir = $node->basedir . '/tablespace_other';
-	mkdir($tablespace_dir);
-	$tablespace_dir = TestLib::perl2host($tablespace_dir);
-	$node->safe_psql('postgres',
-		"CREATE TABLESPACE other LOCATION '$tablespace_dir';");
-
-	# Test direct truncation optimization.  No tuples.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE trunc (id serial PRIMARY KEY);
-		TRUNCATE trunc;
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	my $result = $node->safe_psql('postgres', "SELECT count(*) FROM trunc;");
-	is($result, qq(0), "wal_level = $wal_level, TRUNCATE with empty table");
-
-	# Test truncation with inserted tuples within the same transaction.
-	# Tuples inserted after the truncation should be seen.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE trunc_ins (id serial PRIMARY KEY);
-		INSERT INTO trunc_ins VALUES (DEFAULT);
-		TRUNCATE trunc_ins;
-		INSERT INTO trunc_ins VALUES (DEFAULT);
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres',
-		"SELECT count(*), min(id) FROM trunc_ins;");
-	is($result, qq(1|2), "wal_level = $wal_level, TRUNCATE INSERT");
-
-	# Same for prepared transaction.
-	# Tuples inserted after the truncation should be seen.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE twophase (id serial PRIMARY KEY);
-		INSERT INTO twophase VALUES (DEFAULT);
-		TRUNCATE twophase;
-		INSERT INTO twophase VALUES (DEFAULT);
-		PREPARE TRANSACTION 't';
-		COMMIT PREPARED 't';");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres',
-		"SELECT count(*), min(id) FROM trunc_ins;");
-	is($result, qq(1|2), "wal_level = $wal_level, TRUNCATE INSERT PREPARE");
-
-	# Writing WAL at end of xact, instead of syncing.
-	$node->safe_psql(
-		'postgres', "
-		SET wal_skip_threshold = '1TB';
-		BEGIN;
-		CREATE TABLE noskip (id serial PRIMARY KEY);
-		INSERT INTO noskip (SELECT FROM generate_series(1, 20000) a) ;
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM noskip;");
-	is($result, qq(20000), "wal_level = $wal_level, end-of-xact WAL");
-
-	# Data file for COPY query in subsequent tests
-	my $basedir   = $node->basedir;
-	my $copy_file = "$basedir/copy_data.txt";
-	TestLib::append_to_file(
-		$copy_file, qq(20000,30000
-20001,30001
-20002,30002));
-
-	# Test truncation with inserted tuples using both INSERT and COPY.  Tuples
-	# inserted after the truncation should be seen.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE ins_trunc (id serial PRIMARY KEY, id2 int);
-		INSERT INTO ins_trunc VALUES (DEFAULT, generate_series(1,10000));
-		TRUNCATE ins_trunc;
-		INSERT INTO ins_trunc (id, id2) VALUES (DEFAULT, 10000);
-		COPY ins_trunc FROM '$copy_file' DELIMITER ',';
-		INSERT INTO ins_trunc (id, id2) VALUES (DEFAULT, 10000);
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM ins_trunc;");
-	is($result, qq(5), "wal_level = $wal_level, TRUNCATE COPY INSERT");
-
-	# Test truncation with inserted tuples using COPY.  Tuples copied after
-	# the truncation should be seen.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE trunc_copy (id serial PRIMARY KEY, id2 int);
-		INSERT INTO trunc_copy VALUES (DEFAULT, generate_series(1,3000));
-		TRUNCATE trunc_copy;
-		COPY trunc_copy FROM '$copy_file' DELIMITER ',';
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result =
-	  $node->safe_psql('postgres', "SELECT count(*) FROM trunc_copy;");
-	is($result, qq(3), "wal_level = $wal_level, TRUNCATE COPY");
-
-	# Like previous test, but rollback SET TABLESPACE in a subtransaction.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE spc_abort (id serial PRIMARY KEY, id2 int);
-		INSERT INTO spc_abort VALUES (DEFAULT, generate_series(1,3000));
-		TRUNCATE spc_abort;
-		SAVEPOINT s;
-		  ALTER TABLE spc_abort SET TABLESPACE other; ROLLBACK TO s;
-		COPY spc_abort FROM '$copy_file' DELIMITER ',';
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM spc_abort;");
-	is($result, qq(3),
-		"wal_level = $wal_level, SET TABLESPACE abort subtransaction");
-
-	# in different subtransaction patterns
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE spc_commit (id serial PRIMARY KEY, id2 int);
-		INSERT INTO spc_commit VALUES (DEFAULT, generate_series(1,3000));
-		TRUNCATE spc_commit;
-		SAVEPOINT s; ALTER TABLE spc_commit SET TABLESPACE other; RELEASE s;
-		COPY spc_commit FROM '$copy_file' DELIMITER ',';
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result =
-	  $node->safe_psql('postgres', "SELECT count(*) FROM spc_commit;");
-	is($result, qq(3),
-		"wal_level = $wal_level, SET TABLESPACE commit subtransaction");
-
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE spc_nest (id serial PRIMARY KEY, id2 int);
-		INSERT INTO spc_nest VALUES (DEFAULT, generate_series(1,3000));
-		TRUNCATE spc_nest;
-		SAVEPOINT s;
-			ALTER TABLE spc_nest SET TABLESPACE other;
-			SAVEPOINT s2;
-				ALTER TABLE spc_nest SET TABLESPACE pg_default;
-			ROLLBACK TO s2;
-			SAVEPOINT s2;
-				ALTER TABLE spc_nest SET TABLESPACE pg_default;
-			RELEASE s2;
-		ROLLBACK TO s;
-		COPY spc_nest FROM '$copy_file' DELIMITER ',';
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM spc_nest;");
-	is($result, qq(3),
-		"wal_level = $wal_level, SET TABLESPACE nested subtransaction");
-
-	$node->safe_psql(
-		'postgres', "
-		CREATE TABLE spc_hint (id int);
-		INSERT INTO spc_hint VALUES (1);
-		BEGIN;
-		ALTER TABLE spc_hint SET TABLESPACE other;
-		CHECKPOINT;
-		SELECT * FROM spc_hint;  -- set hint bit
-		INSERT INTO spc_hint VALUES (2);
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM spc_hint;");
-	is($result, qq(2), "wal_level = $wal_level, SET TABLESPACE, hint bit");
-
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE idx_hint (c int PRIMARY KEY);
-		SAVEPOINT q; INSERT INTO idx_hint VALUES (1); ROLLBACK TO q;
-		CHECKPOINT;
-		INSERT INTO idx_hint VALUES (1);  -- set index hint bit
-		INSERT INTO idx_hint VALUES (2);
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->psql('postgres',);
-	my ($ret, $stdout, $stderr) =
-	  $node->psql('postgres', "INSERT INTO idx_hint VALUES (2);");
-	is($ret, qq(3), "wal_level = $wal_level, unique index LP_DEAD");
-	like(
-		$stderr,
-		qr/violates unique/,
-		"wal_level = $wal_level, unique index LP_DEAD message");
-
-	# UPDATE touches two buffers for one row.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE upd (id serial PRIMARY KEY, id2 int);
-		INSERT INTO upd (id, id2) VALUES (DEFAULT, generate_series(1,10000));
-		COPY upd FROM '$copy_file' DELIMITER ',';
-		UPDATE upd SET id2 = id2 + 1;
-		DELETE FROM upd;
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM upd;");
-	is($result, qq(0),
-		"wal_level = $wal_level, UPDATE touches two buffers for one row");
-
-	# Test consistency of COPY with INSERT for table created in the same
-	# transaction.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE ins_copy (id serial PRIMARY KEY, id2 int);
-		INSERT INTO ins_copy VALUES (DEFAULT, 1);
-		COPY ins_copy FROM '$copy_file' DELIMITER ',';
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM ins_copy;");
-	is($result, qq(4), "wal_level = $wal_level, INSERT COPY");
-
-	# Test consistency of COPY that inserts more to the same table using
-	# triggers.  If the INSERTS from the trigger go to the same block data
-	# is copied to, and the INSERTs are WAL-logged, WAL replay will fail when
-	# it tries to replay the WAL record but the "before" image doesn't match,
-	# because not all changes were WAL-logged.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE ins_trig (id serial PRIMARY KEY, id2 text);
-		CREATE FUNCTION ins_trig_before_row_trig() RETURNS trigger
-		  LANGUAGE plpgsql as \$\$
-		  BEGIN
-			IF new.id2 NOT LIKE 'triggered%' THEN
-			  INSERT INTO ins_trig
-				VALUES (DEFAULT, 'triggered row before' || NEW.id2);
-			END IF;
-			RETURN NEW;
-		  END; \$\$;
-		CREATE FUNCTION ins_trig_after_row_trig() RETURNS trigger
-		  LANGUAGE plpgsql as \$\$
-		  BEGIN
-			IF new.id2 NOT LIKE 'triggered%' THEN
-			  INSERT INTO ins_trig
-				VALUES (DEFAULT, 'triggered row after' || NEW.id2);
-			END IF;
-			RETURN NEW;
-		  END; \$\$;
-		CREATE TRIGGER ins_trig_before_row_insert
-		  BEFORE INSERT ON ins_trig
-		  FOR EACH ROW EXECUTE PROCEDURE ins_trig_before_row_trig();
-		CREATE TRIGGER ins_trig_after_row_insert
-		  AFTER INSERT ON ins_trig
-		  FOR EACH ROW EXECUTE PROCEDURE ins_trig_after_row_trig();
-		COPY ins_trig FROM '$copy_file' DELIMITER ',';
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result = $node->safe_psql('postgres', "SELECT count(*) FROM ins_trig;");
-	is($result, qq(9), "wal_level = $wal_level, COPY with INSERT triggers");
-
-	# Test consistency of INSERT, COPY and TRUNCATE in same transaction block
-	# with TRUNCATE triggers.
-	$node->safe_psql(
-		'postgres', "
-		BEGIN;
-		CREATE TABLE trunc_trig (id serial PRIMARY KEY, id2 text);
-		CREATE FUNCTION trunc_trig_before_stat_trig() RETURNS trigger
-		  LANGUAGE plpgsql as \$\$
-		  BEGIN
-			INSERT INTO trunc_trig VALUES (DEFAULT, 'triggered stat before');
-			RETURN NULL;
-		  END; \$\$;
-		CREATE FUNCTION trunc_trig_after_stat_trig() RETURNS trigger
-		  LANGUAGE plpgsql as \$\$
-		  BEGIN
-			INSERT INTO trunc_trig VALUES (DEFAULT, 'triggered stat before');
-			RETURN NULL;
-		  END; \$\$;
-		CREATE TRIGGER trunc_trig_before_stat_truncate
-		  BEFORE TRUNCATE ON trunc_trig
-		  FOR EACH STATEMENT EXECUTE PROCEDURE trunc_trig_before_stat_trig();
-		CREATE TRIGGER trunc_trig_after_stat_truncate
-		  AFTER TRUNCATE ON trunc_trig
-		  FOR EACH STATEMENT EXECUTE PROCEDURE trunc_trig_after_stat_trig();
-		INSERT INTO trunc_trig VALUES (DEFAULT, 1);
-		TRUNCATE trunc_trig;
-		COPY trunc_trig FROM '$copy_file' DELIMITER ',';
-		COMMIT;");
-	$node->stop('immediate');
-	$node->start;
-	$result =
-	  $node->safe_psql('postgres', "SELECT count(*) FROM trunc_trig;");
-	is($result, qq(4),
-		"wal_level = $wal_level, TRUNCATE COPY with TRUNCATE triggers");
-
-	# Test redo of temp table creation.
-	$node->safe_psql(
-		'postgres', "
-		CREATE TEMP TABLE temp (id serial PRIMARY KEY, id2 text);");
-	$node->stop('immediate');
-	$node->start;
-	check_orphan_relfilenodes($node,
-		"wal_level = $wal_level, no orphan relfilenode remains");
-
-	return;
-}
-
-# Run same test suite for multiple wal_level values.
-run_wal_optimize("minimal");
-run_wal_optimize("replica");

src/test/regress/expected/alter_table.out

@@ -2016,12 +2016,6 @@ select * from another;
 (3 rows)
 
 drop table another;
--- Create an index that skips WAL, then perform a SET DATA TYPE that skips
--- rewriting the index.
-begin;
-create table skip_wal_skip_rewrite_index (c varchar(10) primary key);
-alter table skip_wal_skip_rewrite_index alter c type varchar(20);
-commit;
 -- table's row type
 create table tab1 (a int, b text);
 create table tab2 (x int, y tab1);

src/test/regress/expected/create_table.out

@@ -267,16 +267,3 @@ DEALLOCATE select1;
 -- check that the oid column is added before the primary key is checked
 CREATE TABLE oid_pk (f1 INT, PRIMARY KEY(oid)) WITH OIDS;
 DROP TABLE oid_pk;
--- Verify that subtransaction rollback restores rd_createSubid.
-BEGIN;
-CREATE TABLE remember_create_subid (c int);
-SAVEPOINT q; DROP TABLE remember_create_subid; ROLLBACK TO q;
-COMMIT;
-DROP TABLE remember_create_subid;
--- Verify that subtransaction rollback restores rd_firstRelfilenodeSubid.
-CREATE TABLE remember_node_subid (c int);
-BEGIN;
-ALTER TABLE remember_node_subid ALTER c TYPE bigint;
-SAVEPOINT q; DROP TABLE remember_node_subid; ROLLBACK TO q;
-COMMIT;
-DROP TABLE remember_node_subid;

src/test/regress/sql/alter_table.sql

@@ -1348,13 +1348,6 @@ select * from another;
 
 drop table another;
 
--- Create an index that skips WAL, then perform a SET DATA TYPE that skips
--- rewriting the index.
-begin;
-create table skip_wal_skip_rewrite_index (c varchar(10) primary key);
-alter table skip_wal_skip_rewrite_index alter c type varchar(20);
-commit;
-
 -- table's row type
 create table tab1 (a int, b text);
 create table tab2 (x int, y tab1);

src/test/regress/sql/create_table.sql

@@ -277,18 +277,3 @@ DEALLOCATE select1;
 -- check that the oid column is added before the primary key is checked
 CREATE TABLE oid_pk (f1 INT, PRIMARY KEY(oid)) WITH OIDS;
 DROP TABLE oid_pk;
-
--- Verify that subtransaction rollback restores rd_createSubid.
-BEGIN;
-CREATE TABLE remember_create_subid (c int);
-SAVEPOINT q; DROP TABLE remember_create_subid; ROLLBACK TO q;
-COMMIT;
-DROP TABLE remember_create_subid;
-
--- Verify that subtransaction rollback restores rd_firstRelfilenodeSubid.
-CREATE TABLE remember_node_subid (c int);
-BEGIN;
-ALTER TABLE remember_node_subid ALTER c TYPE bigint;
-SAVEPOINT q; DROP TABLE remember_node_subid; ROLLBACK TO q;
-COMMIT;
-DROP TABLE remember_node_subid;