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| author | Robert Haas <rhaas@postgresql.org> | 2017-03-21 09:48:04 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2017-03-21 09:48:04 -0400 |
| commit | d3cc37f1d801a6b5cad9bf179274a8d767f1ee50 (patch) | |
| tree | 88dd5a0133f46b2eb015b4fd2ce69f1b3c30bb56 /src/backend/executor/nodeModifyTable.c | |
| parent | d5286aa905c9173b3fc4f911682089149bd3caef (diff) | |
| download | postgresql-d3cc37f1d801a6b5cad9bf179274a8d767f1ee50.tar.gz postgresql-d3cc37f1d801a6b5cad9bf179274a8d767f1ee50.zip | |
Don't scan partitioned tables.
Partitioned tables do not contain any data; only their unpartitioned
descendents need to be scanned. However, the partitioned tables still
need to be locked, even though they're not scanned. To make that
work, Append and MergeAppend relations now need to carry a list of
(unscanned) partitioned relations that must be locked, and InitPlan
must lock all partitioned result relations.
Aside from the obvious advantage of avoiding some work at execution
time, this has two other advantages. First, it may improve the
planner's decision-making in some cases since the empty relation
might throw things off. Second, it paves the way to getting rid of
the storage for partitioned tables altogether.
Amit Langote, reviewed by me.
Discussion: http://postgr.es/m/6837c359-45c4-8044-34d1-736756335a15@lab.ntt.co.jp
Diffstat (limited to 'src/backend/executor/nodeModifyTable.c')
| -rw-r--r-- | src/backend/executor/nodeModifyTable.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c index 95e158970c3..29c6a6e1d8d 100644 --- a/src/backend/executor/nodeModifyTable.c +++ b/src/backend/executor/nodeModifyTable.c @@ -45,6 +45,7 @@ #include "foreign/fdwapi.h" #include "miscadmin.h" #include "nodes/nodeFuncs.h" +#include "parser/parsetree.h" #include "storage/bufmgr.h" #include "storage/lmgr.h" #include "utils/builtins.h" @@ -1725,8 +1726,20 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags) estate->es_result_relation_info = saved_resultRelInfo; + /* The root table RT index is at the head of the partitioned_rels list */ + if (node->partitioned_rels) + { + Index root_rti; + Oid root_oid; + + root_rti = linitial_int(node->partitioned_rels); + root_oid = getrelid(root_rti, estate->es_range_table); + rel = heap_open(root_oid, NoLock); /* locked by InitPlan */ + } + else + rel = mtstate->resultRelInfo->ri_RelationDesc; + /* Build state for INSERT tuple routing */ - rel = mtstate->resultRelInfo->ri_RelationDesc; if (operation == CMD_INSERT && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { @@ -1897,6 +1910,10 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags) mtstate->ps.ps_ExprContext = NULL; } + /* Close the root partitioned rel if we opened it above. */ + if (rel != mtstate->resultRelInfo->ri_RelationDesc) + heap_close(rel, NoLock); + /* * If needed, Initialize target list, projection and qual for ON CONFLICT * DO UPDATE. |