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Change the bootstrap sequence so that toast tables for system catalogs are
created in the bootstrap phase proper, rather than added after-the-fact by initdb. This is cleaner than before because it allows us to retire the undocumented ALTER TABLE ... CREATE TOAST TABLE command, but the real reason I'm doing it is so that toast tables of shared catalogs will now have predetermined OIDs. This will allow a reasonably clean solution to the problem of locking tables before we load their relcache entries, to appear in a forthcoming patch.
This commit is contained in:
Tom Lane
@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.196 2006/07/14 14:52:18 momjian Exp $
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* $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.197 2006/07/31 01:16:37 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -17,7 +17,6 @@
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#include "access/genam.h"
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#include "access/heapam.h"
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#include "access/reloptions.h"
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#include "access/tuptoaster.h"
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#include "access/xact.h"
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#include "catalog/catalog.h"
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#include "catalog/dependency.h"
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@ -29,9 +28,9 @@
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#include "catalog/pg_depend.h"
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#include "catalog/pg_inherits.h"
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#include "catalog/pg_namespace.h"
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#include "catalog/pg_opclass.h"
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#include "catalog/pg_trigger.h"
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#include "catalog/pg_type.h"
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#include "catalog/toasting.h"
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#include "commands/cluster.h"
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#include "commands/defrem.h"
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#include "commands/tablecmds.h"
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@ -170,7 +169,6 @@ static void StoreCatalogInheritance1(Oid relationId, Oid parentOid,
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int16 seqNumber, Relation catalogRelation);
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static int findAttrByName(const char *attributeName, List *schema);
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static void setRelhassubclassInRelation(Oid relationId, bool relhassubclass);
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static bool needs_toast_table(Relation rel);
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static void AlterIndexNamespaces(Relation classRel, Relation rel,
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Oid oldNspOid, Oid newNspOid);
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static void AlterSeqNamespaces(Relation classRel, Relation rel,
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@ -2073,12 +2071,6 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
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ATPrepAlterColumnType(wqueue, tab, rel, recurse, recursing, cmd);
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pass = AT_PASS_ALTER_TYPE;
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break;
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case AT_ToastTable: /* CREATE TOAST TABLE */
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ATSimplePermissions(rel, false);
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/* This command never recurses */
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/* No command-specific prep needed */
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pass = AT_PASS_MISC;
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break;
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case AT_ChangeOwner: /* ALTER OWNER */
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/* This command never recurses */
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/* No command-specific prep needed */
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@ -2196,8 +2188,8 @@ ATRewriteCatalogs(List **wqueue)
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}
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/*
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* Do an implicit CREATE TOAST TABLE if we executed any subcommands that
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* might have added a column or changed column storage.
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* Check to see if a toast table must be added, if we executed any
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* subcommands that might have added a column or changed column storage.
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*/
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foreach(ltab, *wqueue)
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{
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@ -2207,7 +2199,7 @@ ATRewriteCatalogs(List **wqueue)
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(tab->subcmds[AT_PASS_ADD_COL] ||
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tab->subcmds[AT_PASS_ALTER_TYPE] ||
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tab->subcmds[AT_PASS_COL_ATTRS]))
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AlterTableCreateToastTable(tab->relid, true);
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AlterTableCreateToastTable(tab->relid);
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}
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}
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@ -2261,9 +2253,6 @@ ATExecCmd(AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd)
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case AT_AlterColumnType: /* ALTER COLUMN TYPE */
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ATExecAlterColumnType(tab, rel, cmd->name, (TypeName *) cmd->def);
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break;
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case AT_ToastTable: /* CREATE TOAST TABLE */
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AlterTableCreateToastTable(RelationGetRelid(rel), false);
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break;
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case AT_ChangeOwner: /* ALTER OWNER */
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ATExecChangeOwner(RelationGetRelid(rel),
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get_roleid_checked(cmd->name),
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@ -6541,275 +6530,6 @@ ATExecDropInherits(Relation rel, RangeVar *parent)
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}
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/*
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* ALTER TABLE CREATE TOAST TABLE
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*
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* Note: this is also invoked from outside this module; in such cases we
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* expect the caller to have verified that the relation is a table and we
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* have all the right permissions. Callers expect this function
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* to end with CommandCounterIncrement if it makes any changes.
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*/
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void
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AlterTableCreateToastTable(Oid relOid, bool silent)
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{
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Relation rel;
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HeapTuple reltup;
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TupleDesc tupdesc;
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bool shared_relation;
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Relation class_rel;
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Oid toast_relid;
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Oid toast_idxid;
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char toast_relname[NAMEDATALEN];
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char toast_idxname[NAMEDATALEN];
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IndexInfo *indexInfo;
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Oid classObjectId[2];
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ObjectAddress baseobject,
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toastobject;
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/*
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* Grab an exclusive lock on the target table, which we will NOT release
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* until end of transaction. (This is probably redundant in all present
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* uses...)
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*/
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rel = heap_open(relOid, AccessExclusiveLock);
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/*
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* Toast table is shared if and only if its parent is.
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*
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* We cannot allow toasting a shared relation after initdb (because
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* there's no way to mark it toasted in other databases' pg_class).
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* Unfortunately we can't distinguish initdb from a manually started
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* standalone backend (toasting happens after the bootstrap phase, so
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* checking IsBootstrapProcessingMode() won't work). However, we can at
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* least prevent this mistake under normal multi-user operation.
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*/
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shared_relation = rel->rd_rel->relisshared;
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if (shared_relation && IsUnderPostmaster)
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ereport(ERROR,
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("shared tables cannot be toasted after initdb")));
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/*
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* Is it already toasted?
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*/
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if (rel->rd_rel->reltoastrelid != InvalidOid)
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{
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if (silent)
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{
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heap_close(rel, NoLock);
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return;
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}
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ereport(ERROR,
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("table \"%s\" already has a TOAST table",
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RelationGetRelationName(rel))));
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}
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/*
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* Check to see whether the table actually needs a TOAST table.
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*/
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if (!needs_toast_table(rel))
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{
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if (silent)
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{
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heap_close(rel, NoLock);
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return;
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}
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ereport(ERROR,
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("table \"%s\" does not need a TOAST table",
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RelationGetRelationName(rel))));
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}
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/*
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* Create the toast table and its index
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*/
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snprintf(toast_relname, sizeof(toast_relname),
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"pg_toast_%u", relOid);
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snprintf(toast_idxname, sizeof(toast_idxname),
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"pg_toast_%u_index", relOid);
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/* this is pretty painful... need a tuple descriptor */
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tupdesc = CreateTemplateTupleDesc(3, false);
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TupleDescInitEntry(tupdesc, (AttrNumber) 1,
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"chunk_id",
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OIDOID,
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-1, 0);
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TupleDescInitEntry(tupdesc, (AttrNumber) 2,
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"chunk_seq",
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INT4OID,
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-1, 0);
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TupleDescInitEntry(tupdesc, (AttrNumber) 3,
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"chunk_data",
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BYTEAOID,
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-1, 0);
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/*
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* Ensure that the toast table doesn't itself get toasted, or we'll be
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* toast :-(. This is essential for chunk_data because type bytea is
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* toastable; hit the other two just to be sure.
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*/
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tupdesc->attrs[0]->attstorage = 'p';
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tupdesc->attrs[1]->attstorage = 'p';
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tupdesc->attrs[2]->attstorage = 'p';
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/*
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* Note: the toast relation is placed in the regular pg_toast namespace
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* even if its master relation is a temp table. There cannot be any
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* naming collision, and the toast rel will be destroyed when its master
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* is, so there's no need to handle the toast rel as temp.
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*
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* XXX would it make sense to apply the master's reloptions to the toast
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* table?
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*/
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toast_relid = heap_create_with_catalog(toast_relname,
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PG_TOAST_NAMESPACE,
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rel->rd_rel->reltablespace,
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InvalidOid,
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rel->rd_rel->relowner,
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tupdesc,
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RELKIND_TOASTVALUE,
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shared_relation,
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true,
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0,
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ONCOMMIT_NOOP,
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(Datum) 0,
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true);
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/* make the toast relation visible, else index creation will fail */
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CommandCounterIncrement();
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/*
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* Create unique index on chunk_id, chunk_seq.
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*
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* NOTE: the normal TOAST access routines could actually function with a
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* single-column index on chunk_id only. However, the slice access
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* routines use both columns for faster access to an individual chunk. In
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* addition, we want it to be unique as a check against the possibility of
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* duplicate TOAST chunk OIDs. The index might also be a little more
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* efficient this way, since btree isn't all that happy with large numbers
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* of equal keys.
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*/
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indexInfo = makeNode(IndexInfo);
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indexInfo->ii_NumIndexAttrs = 2;
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indexInfo->ii_KeyAttrNumbers[0] = 1;
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indexInfo->ii_KeyAttrNumbers[1] = 2;
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indexInfo->ii_Expressions = NIL;
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indexInfo->ii_ExpressionsState = NIL;
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indexInfo->ii_Predicate = NIL;
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indexInfo->ii_PredicateState = NIL;
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indexInfo->ii_Unique = true;
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classObjectId[0] = OID_BTREE_OPS_OID;
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classObjectId[1] = INT4_BTREE_OPS_OID;
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toast_idxid = index_create(toast_relid, toast_idxname, InvalidOid,
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indexInfo,
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BTREE_AM_OID,
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rel->rd_rel->reltablespace,
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classObjectId, (Datum) 0,
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true, true, false, true, false);
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/*
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* Store the toast table's OID in the parent relation's pg_class row
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*/
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class_rel = heap_open(RelationRelationId, RowExclusiveLock);
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reltup = SearchSysCacheCopy(RELOID,
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ObjectIdGetDatum(relOid),
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0, 0, 0);
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if (!HeapTupleIsValid(reltup))
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elog(ERROR, "cache lookup failed for relation %u", relOid);
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((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
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simple_heap_update(class_rel, &reltup->t_self, reltup);
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/* Keep catalog indexes current */
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CatalogUpdateIndexes(class_rel, reltup);
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heap_freetuple(reltup);
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heap_close(class_rel, RowExclusiveLock);
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/*
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* Register dependency from the toast table to the master, so that the
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* toast table will be deleted if the master is.
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*/
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baseobject.classId = RelationRelationId;
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baseobject.objectId = relOid;
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baseobject.objectSubId = 0;
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toastobject.classId = RelationRelationId;
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toastobject.objectId = toast_relid;
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toastobject.objectSubId = 0;
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recordDependencyOn(&toastobject, &baseobject, DEPENDENCY_INTERNAL);
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/*
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* Clean up and make changes visible
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*/
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heap_close(rel, NoLock);
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CommandCounterIncrement();
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}
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/*
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* Check to see whether the table needs a TOAST table. It does only if
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* (1) there are any toastable attributes, and (2) the maximum length
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* of a tuple could exceed TOAST_TUPLE_THRESHOLD. (We don't want to
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* create a toast table for something like "f1 varchar(20)".)
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*/
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static bool
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needs_toast_table(Relation rel)
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{
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int32 data_length = 0;
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bool maxlength_unknown = false;
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bool has_toastable_attrs = false;
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TupleDesc tupdesc;
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Form_pg_attribute *att;
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int32 tuple_length;
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int i;
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tupdesc = rel->rd_att;
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att = tupdesc->attrs;
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for (i = 0; i < tupdesc->natts; i++)
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{
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if (att[i]->attisdropped)
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continue;
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data_length = att_align(data_length, att[i]->attalign);
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if (att[i]->attlen > 0)
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{
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/* Fixed-length types are never toastable */
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data_length += att[i]->attlen;
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}
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else
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{
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int32 maxlen = type_maximum_size(att[i]->atttypid,
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att[i]->atttypmod);
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if (maxlen < 0)
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maxlength_unknown = true;
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else
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data_length += maxlen;
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if (att[i]->attstorage != 'p')
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has_toastable_attrs = true;
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}
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}
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if (!has_toastable_attrs)
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return false; /* nothing to toast? */
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if (maxlength_unknown)
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return true; /* any unlimited-length attrs? */
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tuple_length = MAXALIGN(offsetof(HeapTupleHeaderData, t_bits) +
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BITMAPLEN(tupdesc->natts)) +
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MAXALIGN(data_length);
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return (tuple_length > TOAST_TUPLE_THRESHOLD);
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}
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/*
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* Execute ALTER TABLE SET SCHEMA
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*
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