Speed up match_eclasses_to_foreign_key_col() when there are many ECs.
Check ec_relids before bothering to iterate through the EC members.
On a perhaps extreme, but still real-world, query in which
match_eclasses_to_foreign_key_col() accounts for the bulk of the
planner's runtime, this saves nearly 40% of the runtime. It's a bit
of a stopgap fix, but it's simple enough to be back-patched to 9.6
where this code came in; so let's do that.
David Rowley
Discussion: https://postgr.es/m/6970.1545327857@sss.pgh.pa.us
Branch
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REL_10_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/affee8b14c68d8ac8815406be39a68403c4a815e
Modified Files
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src/backend/optimizer/path/equivclass.c | 8 ++++++++
1 file changed, 8 insertions(+)
