From c7b7311f6177b90fe5033b8ed2c10dfcbb863eb6 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 6 Jul 2021 12:36:12 -0400 Subject: Avoid doing catalog lookups in postgres_fdw's conversion_error_callback. As in 50371df26, this is a bad idea since the callback can't really know what error is being thrown and thus whether or not it is safe to attempt catalog accesses. Rather than pushing said accesses into the mainline code where they'd usually be a waste of cycles, we can look at the query's rangetable instead. This change does mean that we'll be printing query aliases (if any were used) rather than the table or column's true name. But that doesn't seem like a bad thing: it's certainly a more useful definition in self-join cases, for instance. In any case, it seems unlikely that any applications would be depending on this detail, so it seems safe to change. Patch by me. Original complaint by Andres Freund; Bharath Rupireddy noted the connection to conversion_error_callback. Discussion: https://postgr.es/m/20210106020229.ne5xnuu6wlondjpe@alap3.anarazel.de --- contrib/postgres_fdw/sql/postgres_fdw.sql | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'contrib/postgres_fdw/sql/postgres_fdw.sql') diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql index 286dd99573e..95862e38ed9 100644 --- a/contrib/postgres_fdw/sql/postgres_fdw.sql +++ b/contrib/postgres_fdw/sql/postgres_fdw.sql @@ -1129,9 +1129,11 @@ DROP TABLE reind_fdw_parent; -- conversion error -- =================================================================== ALTER FOREIGN TABLE ft1 ALTER COLUMN c8 TYPE int; -SELECT * FROM ft1 WHERE c1 = 1; -- ERROR -SELECT ft1.c1, ft2.c2, ft1.c8 FROM ft1, ft2 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = 1; -- ERROR -SELECT ft1.c1, ft2.c2, ft1 FROM ft1, ft2 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = 1; -- ERROR +SELECT * FROM ft1 ftx(x1,x2,x3,x4,x5,x6,x7,x8) WHERE x1 = 1; -- ERROR +SELECT ftx.x1, ft2.c2, ftx.x8 FROM ft1 ftx(x1,x2,x3,x4,x5,x6,x7,x8), ft2 + WHERE ftx.x1 = ft2.c1 AND ftx.x1 = 1; -- ERROR +SELECT ftx.x1, ft2.c2, ftx FROM ft1 ftx(x1,x2,x3,x4,x5,x6,x7,x8), ft2 + WHERE ftx.x1 = ft2.c1 AND ftx.x1 = 1; -- ERROR SELECT sum(c2), array_agg(c8) FROM ft1 GROUP BY c8; -- ERROR ALTER FOREIGN TABLE ft1 ALTER COLUMN c8 TYPE user_enum; -- cgit v1.2.3