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Use optimized bitmap set function for membership test in postgres_fdw

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Deparsing logic in postgres_fdw for locking, FROM clause (alias) and Var
(column qualification) does not need to know the exact number of members
involved, which can be calculated with bms_num_members(), but just if
there is more than one relation involved, which is what bms_membership()
does.  The latter is more performant than the former so this shaves a
couple of cycles.

Author: Daniel Gustafsson
Reviewed-by: Ashutosh Bapat, Nathan Bossart
Discussion: https://postgr.es/m/C73594E0-2B67-4E10-BB35-CDE0E41CC384@yesql.se
This commit is contained in:
Michael Paquier 2018-07-01 15:10:10 +09:00
parent feced1387f
commit 65782346a4
1 changed files with 3 additions and 3 deletions
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6
contrib/postgres_fdw/deparse.c
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@ -1076,7 +1076,7 @@ deparseFromExpr(List *quals, deparse_expr_cxt *context)
/* Construct FROM clause */
appendStringInfoString(buf, " FROM ");
deparseFromExprForRel(buf, context->root, scanrel,
(bms_num_members(scanrel->relids) > 1),
(bms_membership(scanrel->relids) == BMS_MULTIPLE),
(Index) 0, NULL, context->params_list);
/* Construct WHERE clause */
@ -1262,7 +1262,7 @@ deparseLockingClause(deparse_expr_cxt *context)
}
/* Add the relation alias if we are here for a join relation */
if (bms_num_members(rel->relids) > 1 &&
if (bms_membership(rel->relids) == BMS_MULTIPLE &&
rc->strength != LCS_NONE)
appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
}
@ -2328,7 +2328,7 @@ deparseVar(Var *node, deparse_expr_cxt *context)
int colno;
/* Qualify columns when multiple relations are involved. */
bool qualify_col = (bms_num_members(relids) > 1);
bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
/*
* If the Var belongs to the foreign relation that is deparsed as a