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Speed up planning when partitions can be pruned at plan time.

Browse Source 
Previously, the planner created RangeTblEntry and RelOptInfo structs
for every partition of a partitioned table, even though many of them
might later be deemed uninteresting thanks to partition pruning logic.
This incurred significant overhead when there are many partitions.
Arrange to postpone creation of these data structures until after
we've processed the query enough to identify restriction quals for
the partitioned table, and then apply partition pruning before not
after creation of each partition's data structures.  In this way
we need not open the partition relations at all for partitions that
the planner has no real interest in.

For queries that can be proven at plan time to access only a small
number of partitions, this patch improves the practical maximum
number of partitions from under 100 to perhaps a few thousand.

Amit Langote, reviewed at various times by Dilip Kumar, Jesper Pedersen,
Yoshikazu Imai, and David Rowley

Discussion: https://postgr.es/m/9d7c5112-cb99-6a47-d3be-cf1ee6862a1d@lab.ntt.co.jp
This commit is contained in:
Tom Lane
2019-03-30 18:58:55 -04:00
parent ad3107b973
commit 428b260f87
16 changed files with 888 additions and 622 deletions
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42
contrib/postgres_fdw/expected/postgres_fdw.out
View File

@ -7141,9 +7141,9 @@ select * from bar where f1 in (select f1 from foo) for update;
QUERY PLAN
----------------------------------------------------------------------------------------------
LockRows
Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
-> Hash Join
Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
Inner Unique: true
Hash Cond: (bar.f1 = foo.f1)
-> Append
@ -7153,15 +7153,15 @@ select * from bar where f1 in (select f1 from foo) for update;
Output: bar2.f1, bar2.f2, bar2.ctid, bar2.*, bar2.tableoid
Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct2 FOR UPDATE
-> Hash
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> HashAggregate
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
Group Key: foo.f1
-> Append
-> Seq Scan on public.foo
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> Foreign Scan on public.foo2
Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
(23 rows)
@ -7179,9 +7179,9 @@ select * from bar where f1 in (select f1 from foo) for share;
QUERY PLAN
----------------------------------------------------------------------------------------------
LockRows
Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
-> Hash Join
Output: bar.f1, bar.f2, bar.ctid, bar.*, bar.tableoid, foo.ctid, foo.*, foo.tableoid
Output: bar.f1, bar.f2, bar.ctid, foo.ctid, bar.*, bar.tableoid, foo.*, foo.tableoid
Inner Unique: true
Hash Cond: (bar.f1 = foo.f1)
-> Append
@ -7191,15 +7191,15 @@ select * from bar where f1 in (select f1 from foo) for share;
Output: bar2.f1, bar2.f2, bar2.ctid, bar2.*, bar2.tableoid
Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct2 FOR SHARE
-> Hash
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> HashAggregate
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
Group Key: foo.f1
-> Append
-> Seq Scan on public.foo
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> Foreign Scan on public.foo2
Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
(23 rows)
@ -7228,15 +7228,15 @@ update bar set f2 = f2 + 100 where f1 in (select f1 from foo);
-> Seq Scan on public.bar
Output: bar.f1, bar.f2, bar.ctid
-> Hash
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> HashAggregate
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
Group Key: foo.f1
-> Append
-> Seq Scan on public.foo
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> Foreign Scan on public.foo2
Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
-> Hash Join
Output: bar2.f1, (bar2.f2 + 100), bar2.f3, bar2.ctid, foo.ctid, foo.*, foo.tableoid
@ -7246,15 +7246,15 @@ update bar set f2 = f2 + 100 where f1 in (select f1 from foo);
Output: bar2.f1, bar2.f2, bar2.f3, bar2.ctid
Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct2 FOR UPDATE
-> Hash
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> HashAggregate
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
Group Key: foo.f1
-> Append
-> Seq Scan on public.foo
Output: foo.ctid, foo.*, foo.tableoid, foo.f1
Output: foo.ctid, foo.f1, foo.*, foo.tableoid
-> Foreign Scan on public.foo2
Output: foo2.ctid, foo2.*, foo2.tableoid, foo2.f1
Output: foo2.ctid, foo2.f1, foo2.*, foo2.tableoid
Remote SQL: SELECT f1, f2, f3, ctid FROM public.loct1
(39 rows)
@ -8460,7 +8460,7 @@ SELECT t1.a,t2.b,t2.c FROM fprt1 t1 LEFT JOIN (SELECT * FROM fprt2 WHERE a < 10)
Foreign Scan
Output: t1.a, ftprt2_p1.b, ftprt2_p1.c
Relations: (public.ftprt1_p1 t1) LEFT JOIN (public.ftprt2_p1 fprt2)
Remote SQL: SELECT r5.a, r7.b, r7.c FROM (public.fprt1_p1 r5 LEFT JOIN public.fprt2_p1 r7 ON (((r5.a = r7.b)) AND ((r5.b = r7.a)) AND ((r7.a < 10)))) WHERE ((r5.a < 10)) ORDER BY r5.a ASC NULLS LAST, r7.b ASC NULLS LAST, r7.c ASC NULLS LAST
Remote SQL: SELECT r5.a, r6.b, r6.c FROM (public.fprt1_p1 r5 LEFT JOIN public.fprt2_p1 r6 ON (((r5.a = r6.b)) AND ((r5.b = r6.a)) AND ((r6.a < 10)))) WHERE ((r5.a < 10)) ORDER BY r5.a ASC NULLS LAST, r6.b ASC NULLS LAST, r6.c ASC NULLS LAST
(4 rows)
SELECT t1.a,t2.b,t2.c FROM fprt1 t1 LEFT JOIN (SELECT * FROM fprt2 WHERE a < 10) t2 ON (t1.a = t2.b and t1.b = t2.a) WHERE t1.a < 10 ORDER BY 1,2,3;