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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2018-10-04 15:48:17 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2018-10-04 15:48:17 -0400 |
| commit | d73f4c74dd34b19c19839f7ae09fb96442728509 (patch) | |
| tree | c90ec26d55c24bfca08d92cb6b43873cb64ae848 /src/backend/commands/copy.c | |
| parent | 9ddef36278a9f676c07d0b4d9f33fa22e48ce3b5 (diff) | |
| download | postgresql-d73f4c74dd34b19c19839f7ae09fb96442728509.tar.gz postgresql-d73f4c74dd34b19c19839f7ae09fb96442728509.zip | |
In the executor, use an array of pointers to access the rangetable.
Instead of doing a lot of list_nth() accesses to es_range_table,
create a flattened pointer array during executor startup and index
into that to get at individual RangeTblEntrys.
This eliminates one source of O(N^2) behavior with lots of partitions.
(I'm not exactly convinced that it's the most important source, but
it's an easy one to fix.)
Amit Langote and David Rowley
Discussion: https://postgr.es/m/468c85d9-540e-66a2-1dde-fec2b741e688@lab.ntt.co.jp
Diffstat (limited to 'src/backend/commands/copy.c')
| -rw-r--r-- | src/backend/commands/copy.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c index df98e4ac626..86b0fb300ff 100644 --- a/src/backend/commands/copy.c +++ b/src/backend/commands/copy.c @@ -2484,9 +2484,8 @@ CopyFrom(CopyState cstate) estate->es_result_relations = resultRelInfo; estate->es_num_result_relations = 1; estate->es_result_relation_info = resultRelInfo; - estate->es_range_table = cstate->range_table; - estate->es_relations = (Relation *) palloc0(list_length(cstate->range_table) * - sizeof(Relation)); + + ExecInitRangeTable(estate, cstate->range_table); /* Set up a tuple slot too */ myslot = ExecInitExtraTupleSlot(estate, tupDesc); |