database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-14 18:42:34 +03:00
Code Activity

Change the way ATExecMergePartitions() handles the name collision

Browse Source 
The name collision happens when the name of the new partition is the same as
the name of one of the merging partitions.  Currently, ATExecMergePartitions()
first gives the new partition a temporary name and then renames it when old
partitions are deleted.  That negatively influences the naming of related
objects like indexes and constrains, which could inherit a temporary name.

This commit changes the implementation in the following way.  A merging
partition gets renamed first, then the new partition is created with the
right name immediately.  This resolves the issue of the naming of related
objects.

Reported-by: Alexander Lakhin
Discussion: https://postgr.es/m/edfbd846-dcc1-42d1-ac26-715691b687d3%40postgrespro.ru
Author: Dmitry Koval, Alexander Korotkov
Reviewed-by: Robert Haas, Justin Pryzby, Pavel Borisov
This commit is contained in:
Alexander Korotkov
2024-04-30 11:54:42 +03:00
parent 5bcbe9813b
commit 885742b9f8
3 changed files with 73 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

63
src/backend/commands/tablecmds.c
View File

@ -21503,9 +21503,6 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
ListCell *listptr;
List *mergingPartitionsList = NIL;
Oid defaultPartOid;
char tmpRelName[NAMEDATALEN];
RangeVar *mergePartName = cmd->name;
bool isSameName = false;
/*
* Lock all merged partitions, check them and create list with partitions
@ -21527,8 +21524,28 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
* function transformPartitionCmdForMerge().
*/
if (equal(name, cmd->name))
{
/* One new partition can have the same name as merged partition. */
isSameName = true;
char tmpRelName[NAMEDATALEN];
/* Generate temporary name. */
sprintf(tmpRelName, "merge-%u-%X-tmp", RelationGetRelid(rel), MyProcPid);
/*
* Rename the existing partition with a temporary name, leaving it
* free for the new partition. We don't need to care about this
* in the future because we're going to eventually drop the
* existing partition anyway.
*/
RenameRelationInternal(RelationGetRelid(mergingPartition),
tmpRelName, false, false);
/*
* We must bump the command counter to make the new partition
* tuple visible for rename.
*/
CommandCounterIncrement();
}
/* Store a next merging partition into the list. */
mergingPartitionsList = lappend(mergingPartitionsList,
@ -21548,15 +21565,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
DetachPartitionFinalize(rel, mergingPartition, false, defaultPartOid);
}
/* Create table for new partition, use partitioned table as model. */
if (isSameName)
{
/* Create partition table with generated temporary name. */
sprintf(tmpRelName, "merge-%u-%X-tmp", RelationGetRelid(rel), MyProcPid);
mergePartName = makeRangeVar(get_namespace_name(RelationGetNamespace(rel)),
tmpRelName, -1);
}
createPartitionTable(mergePartName,
createPartitionTable(cmd->name,
makeRangeVar(get_namespace_name(RelationGetNamespace(rel)),
RelationGetRelationName(rel), -1),
context);
@ -21567,18 +21576,12 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
* excessive, but this is the way we make sure nobody is planning queries
* involving merging partitions.
*/
newPartRel = table_openrv(mergePartName, AccessExclusiveLock);
newPartRel = table_openrv(cmd->name, AccessExclusiveLock);
/* Copy data from merged partitions to new partition. */
moveMergedTablesRows(rel, mergingPartitionsList, newPartRel);
/*
* Attach a new partition to the partitioned table. wqueue = NULL:
* verification for each cloned constraint is not need.
*/
attachPartitionTable(NULL, rel, newPartRel, cmd->bound);
/* Unlock and drop merged partitions. */
/* Drop the current partitions before attaching the new one. */
foreach(listptr, mergingPartitionsList)
{
ObjectAddress object;
@ -21596,18 +21599,12 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
}
list_free(mergingPartitionsList);
/* Rename new partition if it is needed. */
if (isSameName)
{
/*
* We must bump the command counter to make the new partition tuple
* visible for rename.
*/
CommandCounterIncrement();
/* Rename partition. */
RenameRelationInternal(RelationGetRelid(newPartRel),
cmd->name->relname, false, false);
}
/*
* Attach a new partition to the partitioned table. wqueue = NULL:
* verification for each cloned constraint is not needed.
*/
attachPartitionTable(NULL, rel, newPartRel, cmd->bound);
/* Keep the lock until commit. */
table_close(newPartRel, NoLock);
}