From: Andrew Gierth Date: Thu, 17 Jan 2019 05:33:01 +0000 (+0000) Subject: Postpone aggregate checks until after collation is assigned. X-Git-Tag: REL9_6_12~35 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=624046abe23f3da003b8db07d7028c70f1c672bd;p=postgresql Postpone aggregate checks until after collation is assigned. Previously, parseCheckAggregates was run before assign_query_collations, but this causes problems if any expression has already had a collation assigned by some transform function (e.g. transformCaseExpr) before parseCheckAggregates runs. The differing collations would cause expressions not to be recognized as equal to the ones in the GROUP BY clause, leading to spurious errors about unaggregated column references. The result was that CASE expr WHEN val ... would fail when "expr" contained a GROUPING() expression or matched one of the group by expressions, and where collatable types were involved; whereas the supposedly identical CASE WHEN expr = val ... would succeed. Backpatch all the way; this appears to have been wrong ever since collations were introduced. Per report from Guillaume Lelarge, analysis and patch by me. Discussion: https://postgr.es/m/CAECtzeVSO_US8C2Khgfv54ZMUOBR4sWq+6_bLrETnWExHT=rFg@mail.gmail.com Discussion: https://postgr.es/m/87muo0k0c7.fsf@news-spur.riddles.org.uk --- diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index cf1c123b72..502b103685 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -418,11 +418,13 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt) qry->hasSubLinks = pstate->p_hasSubLinks; qry->hasWindowFuncs = pstate->p_hasWindowFuncs; qry->hasAggs = pstate->p_hasAggs; - if (pstate->p_hasAggs) - parseCheckAggregates(pstate, qry); assign_query_collations(pstate, qry); + /* this must be done after collations, for reliable comparison of exprs */ + if (pstate->p_hasAggs) + parseCheckAggregates(pstate, qry); + return qry; } @@ -1255,8 +1257,6 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt) qry->hasSubLinks = pstate->p_hasSubLinks; qry->hasWindowFuncs = pstate->p_hasWindowFuncs; qry->hasAggs = pstate->p_hasAggs; - if (pstate->p_hasAggs || qry->groupClause || qry->groupingSets || qry->havingQual) - parseCheckAggregates(pstate, qry); foreach(l, stmt->lockingClause) { @@ -1266,6 +1266,10 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt) assign_query_collations(pstate, qry); + /* this must be done after collations, for reliable comparison of exprs */ + if (pstate->p_hasAggs || qry->groupClause || qry->groupingSets || qry->havingQual) + parseCheckAggregates(pstate, qry); + return qry; } @@ -1715,8 +1719,6 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt) qry->hasSubLinks = pstate->p_hasSubLinks; qry->hasWindowFuncs = pstate->p_hasWindowFuncs; qry->hasAggs = pstate->p_hasAggs; - if (pstate->p_hasAggs || qry->groupClause || qry->groupingSets || qry->havingQual) - parseCheckAggregates(pstate, qry); foreach(l, lockingClause) { @@ -1726,6 +1728,10 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt) assign_query_collations(pstate, qry); + /* this must be done after collations, for reliable comparison of exprs */ + if (pstate->p_hasAggs || qry->groupClause || qry->groupingSets || qry->havingQual) + parseCheckAggregates(pstate, qry); + return qry; } diff --git a/src/test/regress/expected/aggregates.out b/src/test/regress/expected/aggregates.out index e768b1fe6d..a1663f08c2 100644 --- a/src/test/regress/expected/aggregates.out +++ b/src/test/regress/expected/aggregates.out @@ -2047,3 +2047,22 @@ SELECT balk(hundred) FROM tenk1; (1 row) ROLLBACK; +-- check collation-sensitive matching between grouping expressions +select v||'a', case v||'a' when 'aa' then 1 else 0 end, count(*) + from unnest(array['a','b']) u(v) + group by v||'a' order by 1; + ?column? | case | count +----------+------+------- + aa | 1 | 1 + ba | 0 | 1 +(2 rows) + +select v||'a', case when v||'a' = 'aa' then 1 else 0 end, count(*) + from unnest(array['a','b']) u(v) + group by v||'a' order by 1; + ?column? | case | count +----------+------+------- + aa | 1 | 1 + ba | 0 | 1 +(2 rows) + diff --git a/src/test/regress/expected/groupingsets.out b/src/test/regress/expected/groupingsets.out index 976050c2d0..44fe5afcdc 100644 --- a/src/test/regress/expected/groupingsets.out +++ b/src/test/regress/expected/groupingsets.out @@ -921,4 +921,29 @@ select sum(ten) from onek group by rollup(four::text), two order by 1; 2500 (6 rows) +-- check collation-sensitive matching between grouping expressions +-- (similar to a check for aggregates, but there are additional code +-- paths for GROUPING, so check again here) +select v||'a', case grouping(v||'a') when 1 then 1 else 0 end, count(*) + from unnest(array[1,1], array['a','b']) u(i,v) + group by rollup(i, v||'a') order by 1,3; + ?column? | case | count +----------+------+------- + aa | 0 | 1 + ba | 0 | 1 + | 1 | 2 + | 1 | 2 +(4 rows) + +select v||'a', case when grouping(v||'a') = 1 then 1 else 0 end, count(*) + from unnest(array[1,1], array['a','b']) u(i,v) + group by rollup(i, v||'a') order by 1,3; + ?column? | case | count +----------+------+------- + aa | 0 | 1 + ba | 0 | 1 + | 1 | 2 + | 1 | 2 +(4 rows) + -- end diff --git a/src/test/regress/sql/aggregates.sql b/src/test/regress/sql/aggregates.sql index cb28f4cffe..7e129f74bc 100644 --- a/src/test/regress/sql/aggregates.sql +++ b/src/test/regress/sql/aggregates.sql @@ -900,3 +900,11 @@ EXPLAIN (COSTS OFF) SELECT balk(hundred) FROM tenk1; SELECT balk(hundred) FROM tenk1; ROLLBACK; + +-- check collation-sensitive matching between grouping expressions +select v||'a', case v||'a' when 'aa' then 1 else 0 end, count(*) + from unnest(array['a','b']) u(v) + group by v||'a' order by 1; +select v||'a', case when v||'a' = 'aa' then 1 else 0 end, count(*) + from unnest(array['a','b']) u(v) + group by v||'a' order by 1; diff --git a/src/test/regress/sql/groupingsets.sql b/src/test/regress/sql/groupingsets.sql index 77cdb5acba..85830e92d2 100644 --- a/src/test/regress/sql/groupingsets.sql +++ b/src/test/regress/sql/groupingsets.sql @@ -255,4 +255,15 @@ select array(select row(v.a,s1.*) from (select two,four, count(*) from onek grou select sum(ten) from onek group by two, rollup(four::text) order by 1; select sum(ten) from onek group by rollup(four::text), two order by 1; +-- check collation-sensitive matching between grouping expressions +-- (similar to a check for aggregates, but there are additional code +-- paths for GROUPING, so check again here) + +select v||'a', case grouping(v||'a') when 1 then 1 else 0 end, count(*) + from unnest(array[1,1], array['a','b']) u(i,v) + group by rollup(i, v||'a') order by 1,3; +select v||'a', case when grouping(v||'a') = 1 then 1 else 0 end, count(*) + from unnest(array[1,1], array['a','b']) u(i,v) + group by rollup(i, v||'a') order by 1,3; + -- end