mirror of
https://github.com/postgres/postgres.git
synced 2025-06-20 15:22:23 +03:00
Code review for CLUSTER ALL patch. Fix bogus locking, incorrect transaction
stop/start nesting, other infelicities.
This commit is contained in:
Tom Lane
@ -11,7 +11,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.102 2002/12/06 05:00:10 momjian Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.103 2002/12/30 18:42:13 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -36,6 +36,7 @@
|
||||
#include "utils/syscache.h"
|
||||
#include "utils/relcache.h"
|
||||
|
||||
|
||||
/*
|
||||
* We need one of these structs for each index in the relation to be
|
||||
* clustered. It's basically the data needed by index_create() so
|
||||
@ -51,7 +52,8 @@ typedef struct
|
||||
bool isclustered;
|
||||
} IndexAttrs;
|
||||
|
||||
/* This struct is used to pass around the information on tables to be
|
||||
/*
|
||||
* This struct is used to pass around the information on tables to be
|
||||
* clustered. We need this so we can make a list of them when invoked without
|
||||
* a specific table/index pair.
|
||||
*/
|
||||
@ -59,21 +61,174 @@ typedef struct
|
||||
{
|
||||
Oid tableOid;
|
||||
Oid indexOid;
|
||||
bool isPrevious;
|
||||
} relToCluster;
|
||||
} RelToCluster;
|
||||
|
||||
|
||||
static void cluster_rel(RelToCluster *rv, bool recheck);
|
||||
static Oid make_new_heap(Oid OIDOldHeap, const char *NewName);
|
||||
static void copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex);
|
||||
static void recreate_indexattr(Oid OIDOldHeap, List *indexes);
|
||||
static List *get_indexattr_list(Relation OldHeap, Oid OldIndex);
|
||||
static void rebuild_indexes(Oid OIDOldHeap, List *indexes);
|
||||
static void swap_relfilenodes(Oid r1, Oid r2);
|
||||
static void cluster_rel(relToCluster *rv);
|
||||
static bool check_cluster_ownership(Oid relOid);
|
||||
static List *get_tables_to_cluster(AclId owner);
|
||||
static bool check_cluster_permitted(Oid relOid);
|
||||
static List *get_tables_to_cluster(MemoryContext cluster_context);
|
||||
|
||||
static MemoryContext cluster_context = NULL;
|
||||
|
||||
|
||||
/*---------------------------------------------------------------------------
|
||||
* This cluster code allows for clustering multiple tables at once. Because
|
||||
* of this, we cannot just run everything on a single transaction, or we
|
||||
* would be forced to acquire exclusive locks on all the tables being
|
||||
* clustered, simultaneously --- very likely leading to deadlock.
|
||||
*
|
||||
* To solve this we follow a similar strategy to VACUUM code,
|
||||
* clustering each relation in a separate transaction. For this to work,
|
||||
* we need to:
|
||||
* - provide a separate memory context so that we can pass information in
|
||||
* a way that survives across transactions
|
||||
* - start a new transaction every time a new relation is clustered
|
||||
* - check for validity of the information on to-be-clustered relations,
|
||||
* as someone might have deleted a relation behind our back, or
|
||||
* clustered one on a different index
|
||||
* - end the transaction
|
||||
*
|
||||
* The single-relation case does not have any such overhead.
|
||||
*
|
||||
* We also allow a relation being specified without index. In that case,
|
||||
* the indisclustered bit will be looked up, and an ERROR will be thrown
|
||||
* if there is no index with the bit set.
|
||||
*---------------------------------------------------------------------------
|
||||
*/
|
||||
void
|
||||
cluster(ClusterStmt *stmt)
|
||||
{
|
||||
if (stmt->relation != NULL)
|
||||
{
|
||||
/* This is the single-relation case. */
|
||||
Oid tableOid,
|
||||
indexOid = InvalidOid;
|
||||
Relation rel;
|
||||
RelToCluster rvtc;
|
||||
|
||||
/* Find and lock the table */
|
||||
tableOid = RangeVarGetRelid(stmt->relation, false);
|
||||
|
||||
rel = heap_open(tableOid, AccessExclusiveLock);
|
||||
|
||||
/* Check permissions */
|
||||
if (!check_cluster_permitted(tableOid))
|
||||
elog(ERROR, "CLUSTER: You do not own relation %s",
|
||||
stmt->relation->relname);
|
||||
|
||||
if (stmt->indexname == NULL)
|
||||
{
|
||||
List *index;
|
||||
|
||||
/* We need to find the index that has indisclustered set. */
|
||||
foreach (index, RelationGetIndexList(rel))
|
||||
{
|
||||
HeapTuple idxtuple;
|
||||
Form_pg_index indexForm;
|
||||
|
||||
indexOid = lfirsti(index);
|
||||
idxtuple = SearchSysCache(INDEXRELID,
|
||||
ObjectIdGetDatum(indexOid),
|
||||
0, 0, 0);
|
||||
if (!HeapTupleIsValid(idxtuple))
|
||||
elog(ERROR, "Cache lookup failed for index %u",
|
||||
indexOid);
|
||||
indexForm = (Form_pg_index) GETSTRUCT(idxtuple);
|
||||
if (indexForm->indisclustered)
|
||||
{
|
||||
ReleaseSysCache(idxtuple);
|
||||
break;
|
||||
}
|
||||
ReleaseSysCache(idxtuple);
|
||||
indexOid = InvalidOid;
|
||||
}
|
||||
|
||||
if (!OidIsValid(indexOid))
|
||||
elog(ERROR, "CLUSTER: No previously clustered index found on table \"%s\"",
|
||||
stmt->relation->relname);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* The index is expected to be in the same namespace as the relation. */
|
||||
indexOid = get_relname_relid(stmt->indexname,
|
||||
rel->rd_rel->relnamespace);
|
||||
if (!OidIsValid(indexOid))
|
||||
elog(ERROR, "CLUSTER: cannot find index \"%s\" for table \"%s\"",
|
||||
stmt->indexname, stmt->relation->relname);
|
||||
}
|
||||
|
||||
rvtc.tableOid = tableOid;
|
||||
rvtc.indexOid = indexOid;
|
||||
|
||||
/* close relation, keep lock till commit */
|
||||
heap_close(rel, NoLock);
|
||||
|
||||
/* Do the job */
|
||||
cluster_rel(&rvtc, false);
|
||||
}
|
||||
else
|
||||
{
|
||||
/*
|
||||
* This is the "multi relation" case. We need to cluster all tables
|
||||
* that have some index with indisclustered set.
|
||||
*/
|
||||
MemoryContext cluster_context;
|
||||
List *rv,
|
||||
*rvs;
|
||||
|
||||
/*
|
||||
* We cannot run this form of CLUSTER inside a user transaction block;
|
||||
* we'd be holding locks way too long.
|
||||
*/
|
||||
PreventTransactionChain((void *) stmt, "CLUSTER");
|
||||
|
||||
/*
|
||||
* Create special memory context for cross-transaction storage.
|
||||
*
|
||||
* Since it is a child of QueryContext, it will go away even in case
|
||||
* of error.
|
||||
*/
|
||||
cluster_context = AllocSetContextCreate(QueryContext,
|
||||
"Cluster",
|
||||
ALLOCSET_DEFAULT_MINSIZE,
|
||||
ALLOCSET_DEFAULT_INITSIZE,
|
||||
ALLOCSET_DEFAULT_MAXSIZE);
|
||||
|
||||
/*
|
||||
* Build the list of relations to cluster. Note that this lives in
|
||||
* cluster_context.
|
||||
*/
|
||||
rvs = get_tables_to_cluster(cluster_context);
|
||||
|
||||
/* Commit to get out of starting transaction */
|
||||
CommitTransactionCommand(true);
|
||||
|
||||
/* Ok, now that we've got them all, cluster them one by one */
|
||||
foreach (rv, rvs)
|
||||
{
|
||||
RelToCluster *rvtc = (RelToCluster *) lfirst(rv);
|
||||
|
||||
/* Start a new transaction for each relation. */
|
||||
StartTransactionCommand(true);
|
||||
SetQuerySnapshot(); /* might be needed for functional index */
|
||||
cluster_rel(rvtc, true);
|
||||
CommitTransactionCommand(true);
|
||||
}
|
||||
|
||||
/* Start a new transaction for the cleanup work. */
|
||||
StartTransactionCommand(true);
|
||||
|
||||
/* Clean up working storage */
|
||||
MemoryContextDelete(cluster_context);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* cluster
|
||||
* cluster_rel
|
||||
*
|
||||
* This clusters the table by creating a new, clustered table and
|
||||
* swapping the relfilenodes of the new table and the old table, so
|
||||
@ -85,45 +240,52 @@ static MemoryContext cluster_context = NULL;
|
||||
* same way we do for the relation. Since we are effectively bulk-loading
|
||||
* the new table, it's better to create the indexes afterwards than to fill
|
||||
* them incrementally while we load the table.
|
||||
*
|
||||
* Since we may open a new transaction for each relation, we have to
|
||||
* check that the relation still is what we think it is.
|
||||
*/
|
||||
void
|
||||
cluster_rel(relToCluster *rvtc)
|
||||
static void
|
||||
cluster_rel(RelToCluster *rvtc, bool recheck)
|
||||
{
|
||||
Relation OldHeap,
|
||||
OldIndex;
|
||||
List *indexes;
|
||||
|
||||
/* Check for user-requested abort. */
|
||||
CHECK_FOR_INTERRUPTS();
|
||||
|
||||
/* Check if the relation and index still exist before opening them
|
||||
/*
|
||||
* Since we may open a new transaction for each relation, we have to
|
||||
* check that the relation still is what we think it is.
|
||||
*
|
||||
* If this is a single-transaction CLUSTER, we can skip these tests.
|
||||
* We *must* skip the one on indisclustered since it would reject an
|
||||
* attempt to cluster a not-previously-clustered index.
|
||||
*/
|
||||
if (!SearchSysCacheExists(RELOID,
|
||||
ObjectIdGetDatum(rvtc->tableOid),
|
||||
0, 0, 0) ||
|
||||
!SearchSysCacheExists(RELOID,
|
||||
ObjectIdGetDatum(rvtc->indexOid),
|
||||
0, 0, 0))
|
||||
return;
|
||||
|
||||
/* Check that the user still owns the relation */
|
||||
if (!check_cluster_ownership(rvtc->tableOid))
|
||||
return;
|
||||
|
||||
/* Check that the index is still the one with indisclustered set.
|
||||
* If this is a standalone cluster, skip this test.
|
||||
*/
|
||||
if (rvtc->isPrevious)
|
||||
if (recheck)
|
||||
{
|
||||
HeapTuple tuple;
|
||||
Form_pg_index indexForm;
|
||||
|
||||
/*
|
||||
* Check if the relation and index still exist before opening them
|
||||
*/
|
||||
if (!SearchSysCacheExists(RELOID,
|
||||
ObjectIdGetDatum(rvtc->tableOid),
|
||||
0, 0, 0) ||
|
||||
!SearchSysCacheExists(RELOID,
|
||||
ObjectIdGetDatum(rvtc->indexOid),
|
||||
0, 0, 0))
|
||||
return;
|
||||
|
||||
/* Check that the user still owns the relation */
|
||||
if (!check_cluster_permitted(rvtc->tableOid))
|
||||
return;
|
||||
|
||||
/*
|
||||
* Check that the index is still the one with indisclustered set.
|
||||
*/
|
||||
tuple = SearchSysCache(INDEXRELID,
|
||||
ObjectIdGetDatum(rvtc->indexOid),
|
||||
0, 0, 0);
|
||||
if (!HeapTupleIsValid(tuple))
|
||||
return; /* could have gone away... */
|
||||
indexForm = (Form_pg_index) GETSTRUCT(tuple);
|
||||
if (!indexForm->indisclustered)
|
||||
{
|
||||
@ -135,7 +297,8 @@ cluster_rel(relToCluster *rvtc)
|
||||
|
||||
/*
|
||||
* We grab exclusive access to the target rel and index for the
|
||||
* duration of the transaction.
|
||||
* duration of the transaction. (This is redundant for the single-
|
||||
* transaction case, since cluster() already did it.)
|
||||
*/
|
||||
OldHeap = heap_open(rvtc->tableOid, AccessExclusiveLock);
|
||||
|
||||
@ -162,29 +325,43 @@ cluster_rel(relToCluster *rvtc)
|
||||
elog(ERROR, "CLUSTER: cannot cluster system relation \"%s\"",
|
||||
RelationGetRelationName(OldHeap));
|
||||
|
||||
/* Save the information of all indexes on the relation. */
|
||||
indexes = get_indexattr_list(OldHeap, rvtc->indexOid);
|
||||
|
||||
/* Drop relcache refcnts, but do NOT give up the locks */
|
||||
/* Drop relcache refcnt on OldIndex, but keep lock */
|
||||
index_close(OldIndex);
|
||||
heap_close(OldHeap, NoLock);
|
||||
|
||||
/* rebuild_rel does all the dirty work */
|
||||
rebuild_rel(rvtc->tableOid, rvtc->indexOid, indexes, true);
|
||||
/* rebuild_relation does all the dirty work */
|
||||
rebuild_relation(OldHeap, rvtc->indexOid);
|
||||
|
||||
/* NB: rebuild_relation does heap_close() on OldHeap */
|
||||
}
|
||||
|
||||
/*
|
||||
* rebuild_relation: rebuild an existing relation
|
||||
*
|
||||
* This is shared code between CLUSTER and TRUNCATE. In the TRUNCATE
|
||||
* case, the new relation is built and left empty. In the CLUSTER case,
|
||||
* it is filled with data read from the old relation in the order specified
|
||||
* by the index.
|
||||
*
|
||||
* OldHeap: table to rebuild --- must be opened and exclusive-locked!
|
||||
* indexOid: index to cluster by, or InvalidOid in TRUNCATE case
|
||||
*
|
||||
* NB: this routine closes OldHeap at the right time; caller should not.
|
||||
*/
|
||||
void
|
||||
rebuild_rel(Oid tableOid, Oid indexOid, List *indexes, bool dataCopy)
|
||||
rebuild_relation(Relation OldHeap, Oid indexOid)
|
||||
{
|
||||
Oid tableOid = RelationGetRelid(OldHeap);
|
||||
List *indexes;
|
||||
Oid OIDNewHeap;
|
||||
char NewHeapName[NAMEDATALEN];
|
||||
ObjectAddress object;
|
||||
|
||||
/*
|
||||
* If dataCopy is true, we assume that we will be basing the
|
||||
* copy off an index for cluster operations.
|
||||
*/
|
||||
Assert(!dataCopy || OidIsValid(indexOid));
|
||||
/* Save the information about all indexes on the relation. */
|
||||
indexes = get_indexattr_list(OldHeap, indexOid);
|
||||
|
||||
/* Close relcache entry, but keep lock until transaction commit */
|
||||
heap_close(OldHeap, NoLock);
|
||||
|
||||
/*
|
||||
* Create the new heap, using a temporary name in the same namespace
|
||||
* as the existing table. NOTE: there is some risk of collision with
|
||||
@ -204,7 +381,7 @@ rebuild_rel(Oid tableOid, Oid indexOid, List *indexes, bool dataCopy)
|
||||
/*
|
||||
* Copy the heap data into the new table in the desired order.
|
||||
*/
|
||||
if (dataCopy)
|
||||
if (OidIsValid(indexOid))
|
||||
copy_heap_data(OIDNewHeap, tableOid, indexOid);
|
||||
|
||||
/* To make the new heap's data visible (probably not needed?). */
|
||||
@ -230,9 +407,9 @@ rebuild_rel(Oid tableOid, Oid indexOid, List *indexes, bool dataCopy)
|
||||
|
||||
/*
|
||||
* Recreate each index on the relation. We do not need
|
||||
* CommandCounterIncrement() because recreate_indexattr does it.
|
||||
* CommandCounterIncrement() because rebuild_indexes does it.
|
||||
*/
|
||||
recreate_indexattr(tableOid, indexes);
|
||||
rebuild_indexes(tableOid, indexes);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -335,7 +512,7 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex)
|
||||
* Get the necessary info about the indexes of the relation and
|
||||
* return a list of IndexAttrs structures.
|
||||
*/
|
||||
List *
|
||||
static List *
|
||||
get_indexattr_list(Relation OldHeap, Oid OldIndex)
|
||||
{
|
||||
List *indexes = NIL;
|
||||
@ -366,7 +543,8 @@ get_indexattr_list(Relation OldHeap, Oid OldIndex)
|
||||
palloc(sizeof(Oid) * attrs->indexInfo->ii_NumIndexAttrs);
|
||||
memcpy(attrs->classOID, indexForm->indclass,
|
||||
sizeof(Oid) * attrs->indexInfo->ii_NumIndexAttrs);
|
||||
attrs->isclustered = (OldIndex == indexOID);
|
||||
/* We adjust the isclustered attribute to correct new state */
|
||||
attrs->isclustered = (indexOID == OldIndex);
|
||||
|
||||
/* Name and access method of each index come from pg_class */
|
||||
classTuple = SearchSysCache(RELOID,
|
||||
@ -397,7 +575,7 @@ get_indexattr_list(Relation OldHeap, Oid OldIndex)
|
||||
* the new index (carrying the old index filenode along).
|
||||
*/
|
||||
static void
|
||||
recreate_indexattr(Oid OIDOldHeap, List *indexes)
|
||||
rebuild_indexes(Oid OIDOldHeap, List *indexes)
|
||||
{
|
||||
List *elem;
|
||||
|
||||
@ -629,235 +807,69 @@ swap_relfilenodes(Oid r1, Oid r2)
|
||||
heap_close(relRelation, RowExclusiveLock);
|
||||
}
|
||||
|
||||
/*---------------------------------------------------------------------------
|
||||
* This cluster code allows for clustering multiple tables at once. Because
|
||||
* of this, we cannot just run everything on a single transaction, or we
|
||||
* would be forced to acquire exclusive locks on all the tables being
|
||||
* clustered. To solve this we follow a similar strategy to VACUUM code,
|
||||
* clustering each relation in a separate transaction. For this to work,
|
||||
* we need to:
|
||||
* - provide a separate memory context so that we can pass information in
|
||||
* a way that trascends transactions
|
||||
* - start a new transaction every time a new relation is clustered
|
||||
* - check for validity of the information on to-be-clustered relations,
|
||||
* as someone might have deleted a relation behind our back, or
|
||||
* clustered one on a different index
|
||||
* - end the transaction
|
||||
*
|
||||
* The single relation code does not have any overhead.
|
||||
*
|
||||
* We also allow a relation being specified without index. In that case,
|
||||
* the indisclustered bit will be looked up, and an ERROR will be thrown
|
||||
* if there is no index with the bit set.
|
||||
*---------------------------------------------------------------------------
|
||||
/*
|
||||
* Checks if the user is allowed to cluster (ie, owns) the relation.
|
||||
* Superusers are allowed to cluster any table.
|
||||
*/
|
||||
void
|
||||
cluster(ClusterStmt *stmt)
|
||||
{
|
||||
|
||||
/* This is the single relation case. */
|
||||
if (stmt->relation != NULL)
|
||||
{
|
||||
Oid indexOid = InvalidOid,
|
||||
tableOid;
|
||||
relToCluster rvtc;
|
||||
HeapTuple tuple;
|
||||
Form_pg_class classForm;
|
||||
|
||||
tableOid = RangeVarGetRelid(stmt->relation, false);
|
||||
if (!check_cluster_ownership(tableOid))
|
||||
elog(ERROR, "CLUSTER: You do not own relation %s",
|
||||
stmt->relation->relname);
|
||||
|
||||
tuple = SearchSysCache(RELOID,
|
||||
ObjectIdGetDatum(tableOid),
|
||||
0, 0, 0);
|
||||
if (!HeapTupleIsValid(tuple))
|
||||
elog(ERROR, "Cache lookup failed for relation %u", tableOid);
|
||||
classForm = (Form_pg_class) GETSTRUCT(tuple);
|
||||
|
||||
if (stmt->indexname == NULL)
|
||||
{
|
||||
List *index;
|
||||
Relation rel = RelationIdGetRelation(tableOid);
|
||||
HeapTuple ituple = NULL,
|
||||
idxtuple = NULL;
|
||||
|
||||
/* We need to fetch the index that has indisclustered set. */
|
||||
foreach (index, RelationGetIndexList(rel))
|
||||
{
|
||||
Form_pg_index indexForm;
|
||||
|
||||
indexOid = lfirsti(index);
|
||||
ituple = SearchSysCache(RELOID,
|
||||
ObjectIdGetDatum(indexOid),
|
||||
0, 0, 0);
|
||||
if (!HeapTupleIsValid(ituple))
|
||||
elog(ERROR, "Cache lookup failed for relation %u", indexOid);
|
||||
idxtuple = SearchSysCache(INDEXRELID,
|
||||
ObjectIdGetDatum(HeapTupleGetOid(ituple)),
|
||||
0, 0, 0);
|
||||
if (!HeapTupleIsValid(idxtuple))
|
||||
elog(ERROR, "Cache lookup failed for index %u", HeapTupleGetOid(ituple));
|
||||
indexForm = (Form_pg_index) GETSTRUCT(idxtuple);
|
||||
if (indexForm->indisclustered)
|
||||
break;
|
||||
indexOid = InvalidOid;
|
||||
}
|
||||
if (indexOid == InvalidOid)
|
||||
elog(ERROR, "CLUSTER: No previously clustered index found on table %s",
|
||||
stmt->relation->relname);
|
||||
RelationClose(rel);
|
||||
ReleaseSysCache(ituple);
|
||||
ReleaseSysCache(idxtuple);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* The index is expected to be in the same namespace as the relation. */
|
||||
indexOid = get_relname_relid(stmt->indexname, classForm->relnamespace);
|
||||
}
|
||||
ReleaseSysCache(tuple);
|
||||
|
||||
/* XXX Maybe the namespace should be reported as well */
|
||||
if (!OidIsValid(indexOid))
|
||||
elog(ERROR, "CLUSTER: cannot find index \"%s\" for table \"%s\"",
|
||||
stmt->indexname, stmt->relation->relname);
|
||||
rvtc.tableOid = tableOid;
|
||||
rvtc.indexOid = indexOid;
|
||||
rvtc.isPrevious = false;
|
||||
|
||||
/* Do the job */
|
||||
cluster_rel(&rvtc);
|
||||
}
|
||||
else
|
||||
{
|
||||
/*
|
||||
* This is the "no relation" case. We need to cluster all tables
|
||||
* that have some index with indisclustered set.
|
||||
*/
|
||||
|
||||
relToCluster *rvtc;
|
||||
List *rv,
|
||||
*rvs;
|
||||
|
||||
/*
|
||||
* We cannot run CLUSTER inside a user transaction block; if we were inside
|
||||
* a transaction, then our commit- and start-transaction-command calls
|
||||
* would not have the intended effect!
|
||||
*/
|
||||
if (IsTransactionBlock())
|
||||
elog(ERROR, "CLUSTER cannot run inside a BEGIN/END block");
|
||||
|
||||
/* Running CLUSTER from a function would free the function context */
|
||||
if (!MemoryContextContains(QueryContext, stmt))
|
||||
elog(ERROR, "CLUSTER cannot be called from a function");
|
||||
/*
|
||||
* Create special memory context for cross-transaction storage.
|
||||
*
|
||||
* Since it is a child of QueryContext, it will go away even in case
|
||||
* of error.
|
||||
*/
|
||||
cluster_context = AllocSetContextCreate(QueryContext,
|
||||
"Cluster",
|
||||
ALLOCSET_DEFAULT_MINSIZE,
|
||||
ALLOCSET_DEFAULT_INITSIZE,
|
||||
ALLOCSET_DEFAULT_MAXSIZE);
|
||||
|
||||
/*
|
||||
* Build the list of relations to cluster. Note that this lives in
|
||||
* cluster_context.
|
||||
*/
|
||||
rvs = get_tables_to_cluster(GetUserId());
|
||||
|
||||
/* Ok, now that we've got them all, cluster them one by one */
|
||||
foreach (rv, rvs)
|
||||
{
|
||||
rvtc = (relToCluster *)lfirst(rv);
|
||||
|
||||
/* Start a new transaction for this relation. */
|
||||
StartTransactionCommand(true);
|
||||
cluster_rel(rvtc);
|
||||
CommitTransactionCommand(true);
|
||||
}
|
||||
}
|
||||
|
||||
/* Start a new transaction for the cleanup work. */
|
||||
StartTransactionCommand(true);
|
||||
|
||||
/* Clean up working storage */
|
||||
if (stmt->relation == NULL)
|
||||
{
|
||||
MemoryContextDelete(cluster_context);
|
||||
cluster_context = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
/* Checks if the user owns the relation. Superusers
|
||||
* are allowed to cluster any table.
|
||||
*/
|
||||
bool
|
||||
check_cluster_ownership(Oid relOid)
|
||||
static bool
|
||||
check_cluster_permitted(Oid relOid)
|
||||
{
|
||||
/* Superusers bypass this check */
|
||||
return pg_class_ownercheck(relOid, GetUserId());
|
||||
}
|
||||
|
||||
/* Get a list of tables that the current user owns and
|
||||
/*
|
||||
* Get a list of tables that the current user owns and
|
||||
* have indisclustered set. Return the list in a List * of rvsToCluster
|
||||
* with the tableOid and the indexOid on which the table is already
|
||||
* clustered.
|
||||
*/
|
||||
List *
|
||||
get_tables_to_cluster(AclId owner)
|
||||
static List *
|
||||
get_tables_to_cluster(MemoryContext cluster_context)
|
||||
{
|
||||
Relation indRelation;
|
||||
HeapScanDesc scan;
|
||||
ScanKeyData entry;
|
||||
HeapTuple indexTuple;
|
||||
Form_pg_index index;
|
||||
relToCluster *rvtc;
|
||||
MemoryContext old_context;
|
||||
RelToCluster *rvtc;
|
||||
List *rvs = NIL;
|
||||
|
||||
/*
|
||||
* Get all indexes that have indisclustered set. System
|
||||
* relations or nailed-in relations cannot ever have
|
||||
* indisclustered set, because CLUSTER will refuse to
|
||||
* set it when called with one of them as argument.
|
||||
* Get all indexes that have indisclustered set and are owned by
|
||||
* appropriate user. System relations or nailed-in relations cannot ever
|
||||
* have indisclustered set, because CLUSTER will refuse to set it when
|
||||
* called with one of them as argument.
|
||||
*/
|
||||
indRelation = relation_openr(IndexRelationName, RowExclusiveLock);
|
||||
ScanKeyEntryInitialize(&entry, 0, Anum_pg_index_indisclustered,
|
||||
F_BOOLEQ, true);
|
||||
indRelation = relation_openr(IndexRelationName, AccessShareLock);
|
||||
ScanKeyEntryInitialize(&entry, 0,
|
||||
Anum_pg_index_indisclustered,
|
||||
F_BOOLEQ,
|
||||
BoolGetDatum(true));
|
||||
scan = heap_beginscan(indRelation, SnapshotNow, 1, &entry);
|
||||
while ((indexTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
|
||||
{
|
||||
MemoryContext old_context = NULL;
|
||||
|
||||
index = (Form_pg_index) GETSTRUCT(indexTuple);
|
||||
if (!check_cluster_ownership(index->indrelid))
|
||||
if (!check_cluster_permitted(index->indrelid))
|
||||
continue;
|
||||
|
||||
/*
|
||||
* We have to build the struct in a different memory context so
|
||||
* We have to build the list in a different memory context so
|
||||
* it will survive the cross-transaction processing
|
||||
*/
|
||||
|
||||
old_context = MemoryContextSwitchTo(cluster_context);
|
||||
|
||||
rvtc = (relToCluster *)palloc(sizeof(relToCluster));
|
||||
rvtc->indexOid = index->indexrelid;
|
||||
rvtc = (RelToCluster *) palloc(sizeof(RelToCluster));
|
||||
rvtc->tableOid = index->indrelid;
|
||||
rvtc->isPrevious = true;
|
||||
rvs = lcons((void *)rvtc, rvs);
|
||||
rvtc->indexOid = index->indexrelid;
|
||||
rvs = lcons(rvtc, rvs);
|
||||
|
||||
MemoryContextSwitchTo(old_context);
|
||||
}
|
||||
heap_endscan(scan);
|
||||
|
||||
/*
|
||||
* Release the lock on pg_index. We will check the indexes
|
||||
* later again.
|
||||
*
|
||||
*/
|
||||
relation_close(indRelation, RowExclusiveLock);
|
||||
relation_close(indRelation, AccessShareLock);
|
||||
|
||||
return rvs;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user