From 5dbdb2f799232cb1b6df7d7a85d59ade3234d30c Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 24 Feb 2017 12:21:46 +0530 Subject: [PATCH] Make tablesample work with partitioned tables. This was an oversight in the original partitioning commit. Amit Langote, reviewed by David Fetter Discussion: http://postgr.es/m/59af6590-8ace-04c4-c36c-ea35d435c60e@lab.ntt.co.jp --- src/backend/parser/parse_clause.c | 3 ++- src/test/regress/expected/tablesample.out | 18 ++++++++++++++++++ src/test/regress/sql/tablesample.sql | 8 ++++++++ 3 files changed, 28 insertions(+), 1 deletion(-) diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index fecc1d6598..b5eae56006 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -907,7 +907,8 @@ transformFromClauseItem(ParseState *pstate, Node *n, rte = rt_fetch(rtr->rtindex, pstate->p_rtable); /* We only support this on plain relations and matviews */ if (rte->relkind != RELKIND_RELATION && - rte->relkind != RELKIND_MATVIEW) + rte->relkind != RELKIND_MATVIEW && + rte->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("TABLESAMPLE clause can only be applied to tables and materialized views"), diff --git a/src/test/regress/expected/tablesample.out b/src/test/regress/expected/tablesample.out index 7e91b958ae..b18e420e9b 100644 --- a/src/test/regress/expected/tablesample.out +++ b/src/test/regress/expected/tablesample.out @@ -313,3 +313,21 @@ SELECT q.* FROM (SELECT * FROM test_tablesample) as q TABLESAMPLE BERNOULLI (5); ERROR: syntax error at or near "TABLESAMPLE" LINE 1: ...CT q.* FROM (SELECT * FROM test_tablesample) as q TABLESAMPL... ^ +-- check partitioned tables support tablesample +create table parted_sample (a int) partition by list (a); +create table parted_sample_1 partition of parted_sample for values in (1); +create table parted_sample_2 partition of parted_sample for values in (2); +explain (costs off) + select * from parted_sample tablesample bernoulli (100); + QUERY PLAN +------------------------------------------- + Append + -> Sample Scan on parted_sample + Sampling: bernoulli ('100'::real) + -> Sample Scan on parted_sample_1 + Sampling: bernoulli ('100'::real) + -> Sample Scan on parted_sample_2 + Sampling: bernoulli ('100'::real) +(7 rows) + +drop table parted_sample, parted_sample_1, parted_sample_2; diff --git a/src/test/regress/sql/tablesample.sql b/src/test/regress/sql/tablesample.sql index eec9793496..c39fe4b750 100644 --- a/src/test/regress/sql/tablesample.sql +++ b/src/test/regress/sql/tablesample.sql @@ -100,3 +100,11 @@ WITH query_select AS (SELECT * FROM test_tablesample) SELECT * FROM query_select TABLESAMPLE BERNOULLI (5.5) REPEATABLE (1); SELECT q.* FROM (SELECT * FROM test_tablesample) as q TABLESAMPLE BERNOULLI (5); + +-- check partitioned tables support tablesample +create table parted_sample (a int) partition by list (a); +create table parted_sample_1 partition of parted_sample for values in (1); +create table parted_sample_2 partition of parted_sample for values in (2); +explain (costs off) + select * from parted_sample tablesample bernoulli (100); +drop table parted_sample, parted_sample_1, parted_sample_2;