From 9619fdca106149d9e7bae5db3977435f8ce5f0c2 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 24 Oct 2012 14:54:07 -0400 Subject: [PATCH] Prevent parser from believing that views have system columns. Views should not have any pg_attribute entries for system columns. However, we forgot to remove such entries when converting a table to a view. This could lead to crashes later on, if someone attempted to reference such a column, as reported by Kohei KaiGai. This problem is corrected properly in HEAD (by removing the pg_attribute entries during conversion), but in the back branches we need to defend against existing mis-converted views. This fix costs us an extra syscache lookup per system column reference, which is annoying but probably not really measurable in the big scheme of things. --- src/backend/parser/parse_relation.c | 11 +++++++++-- src/test/regress/expected/rules.out | 22 ++++++++++++++++++++++ src/test/regress/sql/rules.sql | 15 +++++++++++++++ 3 files changed, 46 insertions(+), 2 deletions(-) diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c index 1d0fc82bba..101637cec6 100644 --- a/src/backend/parser/parse_relation.c +++ b/src/backend/parser/parse_relation.c @@ -501,10 +501,17 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte, char *colname, attnum = specialAttNum(colname); if (attnum != InvalidAttrNumber) { - /* now check to see if column actually is defined */ + /* + * Now check to see if column actually is defined. Because of + * an ancient oversight in DefineQueryRewrite, it's possible that + * pg_attribute contains entries for system columns for a view, + * even though views should not have such --- so we also check + * the relkind. This kluge will not be needed in 9.3 and later. + */ if (SearchSysCacheExists2(ATTNUM, ObjectIdGetDatum(rte->relid), - Int16GetDatum(attnum))) + Int16GetDatum(attnum)) && + get_rel_relkind(rte->relid) != RELKIND_VIEW) { var = make_var(pstate, rte, attnum, location); /* Require read access to the column */ diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 87f0e11360..b9610e539f 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1452,6 +1452,28 @@ ERROR: cannot drop rule _RETURN on view fooview because view fooview requires i HINT: You can drop view fooview instead. drop view fooview; -- +-- test conversion of table to view (needed to load some pg_dump files) +-- +create table fooview (x int, y text); +select xmin, * from fooview; + xmin | x | y +------+---+--- +(0 rows) + +create rule "_RETURN" as on select to fooview do instead + select 1 as x, 'aaa'::text as y; +select * from fooview; + x | y +---+----- + 1 | aaa +(1 row) + +select xmin, * from fooview; -- fail, views don't have such a column +ERROR: column "xmin" does not exist +LINE 1: select xmin, * from fooview; + ^ +drop view fooview; +-- -- check for planner problems with complex inherited UPDATES -- create table id (id serial primary key, name text); diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql index c7cf788b20..513fd68b62 100644 --- a/src/test/regress/sql/rules.sql +++ b/src/test/regress/sql/rules.sql @@ -859,6 +859,21 @@ create view fooview as select 'foo'::text; drop rule "_RETURN" on fooview; drop view fooview; +-- +-- test conversion of table to view (needed to load some pg_dump files) +-- + +create table fooview (x int, y text); +select xmin, * from fooview; + +create rule "_RETURN" as on select to fooview do instead + select 1 as x, 'aaa'::text as y; + +select * from fooview; +select xmin, * from fooview; -- fail, views don't have such a column + +drop view fooview; + -- -- check for planner problems with complex inherited UPDATES -- -- 2.40.0