From 82593b9a3d5f1c58157f6e8fd7d69ef0d6f6eeb3 Mon Sep 17 00:00:00 2001 From: Etsuro Fujita Date: Fri, 5 Aug 2022 17:15:00 +0900 Subject: [PATCH] postgres_fdw: Disable batch insertion when there are WCO constraints. When inserting a view referencing a foreign table that has WITH CHECK OPTION constraints, in single-insert mode postgres_fdw retrieves the data that was actually inserted on the remote side so that the WITH CHECK OPTION constraints are enforced with the data locally, but in batch-insert mode it cannot currently retrieve the data (except for the row first inserted through the view), resulting in enforcing the WITH CHECK OPTION constraints with the data passed from the core (except for the first-inserted row), which led to incorrect results when inserting into a view referencing a foreign table in which a remote BEFORE ROW INSERT trigger changes the rows inserted through the view so that they violate the view's WITH CHECK OPTION constraint. Also, the query inserting into the view caused an assertion failure in assert-enabled builds. Fix these by disabling batch insertion when inserting into such a view. Back-patch to v14 where batch insertion was added. Discussion: https://postgr.es/m/CAPmGK17LpbTZs4m4a_6THP54UBeK9fHvX8aVVA%2BC6yEZDZwQcg%40mail.gmail.com --- .../postgres_fdw/expected/postgres_fdw.out | 44 +++++++++++++++++++ contrib/postgres_fdw/postgres_fdw.c | 6 ++- contrib/postgres_fdw/sql/postgres_fdw.sql | 16 +++++++ 3 files changed, 64 insertions(+), 2 deletions(-) diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out index 52d0c3f3ed..7bf35602b0 100644 --- a/contrib/postgres_fdw/expected/postgres_fdw.out +++ b/contrib/postgres_fdw/expected/postgres_fdw.out @@ -6544,6 +6544,29 @@ SELECT * FROM foreign_tbl; 20 | 30 (1 row) +-- We don't allow batch insert when there are any WCO constraints +ALTER SERVER loopback OPTIONS (ADD batch_size '10'); +EXPLAIN (VERBOSE, COSTS OFF) +INSERT INTO rw_view VALUES (0, 15), (0, 5); + QUERY PLAN +-------------------------------------------------------------------------------- + Insert on public.foreign_tbl + Remote SQL: INSERT INTO public.base_tbl(a, b) VALUES ($1, $2) RETURNING a, b + Batch Size: 1 + -> Values Scan on "*VALUES*" + Output: "*VALUES*".column1, "*VALUES*".column2 +(5 rows) + +INSERT INTO rw_view VALUES (0, 15), (0, 5); -- should fail +ERROR: new row violates check option for view "rw_view" +DETAIL: Failing row contains (10, 5). +SELECT * FROM foreign_tbl; + a | b +----+---- + 20 | 30 +(1 row) + +ALTER SERVER loopback OPTIONS (DROP batch_size); DROP FOREIGN TABLE foreign_tbl CASCADE; NOTICE: drop cascades to view rw_view DROP TRIGGER row_before_insupd_trigger ON base_tbl; @@ -6636,6 +6659,27 @@ SELECT * FROM foreign_tbl; 20 | 30 (1 row) +-- We don't allow batch insert when there are any WCO constraints +ALTER SERVER loopback OPTIONS (ADD batch_size '10'); +EXPLAIN (VERBOSE, COSTS OFF) +INSERT INTO rw_view VALUES (0, 15), (0, 5); + QUERY PLAN +-------------------------------------------------------- + Insert on public.parent_tbl + -> Values Scan on "*VALUES*" + Output: "*VALUES*".column1, "*VALUES*".column2 +(3 rows) + +INSERT INTO rw_view VALUES (0, 15), (0, 5); -- should fail +ERROR: new row violates check option for view "rw_view" +DETAIL: Failing row contains (10, 5). +SELECT * FROM foreign_tbl; + a | b +----+---- + 20 | 30 +(1 row) + +ALTER SERVER loopback OPTIONS (DROP batch_size); DROP FOREIGN TABLE foreign_tbl CASCADE; DROP TRIGGER row_before_insupd_trigger ON child_tbl; DROP TABLE parent_tbl CASCADE; diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 048db542d3..16320170ce 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -2043,8 +2043,9 @@ postgresGetForeignModifyBatchSize(ResultRelInfo *resultRelInfo) batch_size = get_batch_size_option(resultRelInfo->ri_RelationDesc); /* - * Disable batching when we have to use RETURNING or there are any - * BEFORE/AFTER ROW INSERT triggers on the foreign table. + * Disable batching when we have to use RETURNING, there are any + * BEFORE/AFTER ROW INSERT triggers on the foreign table, or there are any + * WITH CHECK OPTION constraints from parent views. * * When there are any BEFORE ROW INSERT triggers on the table, we can't * support it, because such triggers might query the table we're inserting @@ -2052,6 +2053,7 @@ postgresGetForeignModifyBatchSize(ResultRelInfo *resultRelInfo) * and prepared for insertion are not there. */ if (resultRelInfo->ri_projectReturning != NULL || + resultRelInfo->ri_WithCheckOptions != NIL || (resultRelInfo->ri_TrigDesc && (resultRelInfo->ri_TrigDesc->trig_insert_before_row || resultRelInfo->ri_TrigDesc->trig_insert_after_row))) diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql index 2a250ee632..42735ae78a 100644 --- a/contrib/postgres_fdw/sql/postgres_fdw.sql +++ b/contrib/postgres_fdw/sql/postgres_fdw.sql @@ -1505,6 +1505,14 @@ UPDATE rw_view SET b = b + 15; UPDATE rw_view SET b = b + 15; -- ok SELECT * FROM foreign_tbl; +-- We don't allow batch insert when there are any WCO constraints +ALTER SERVER loopback OPTIONS (ADD batch_size '10'); +EXPLAIN (VERBOSE, COSTS OFF) +INSERT INTO rw_view VALUES (0, 15), (0, 5); +INSERT INTO rw_view VALUES (0, 15), (0, 5); -- should fail +SELECT * FROM foreign_tbl; +ALTER SERVER loopback OPTIONS (DROP batch_size); + DROP FOREIGN TABLE foreign_tbl CASCADE; DROP TRIGGER row_before_insupd_trigger ON base_tbl; DROP TABLE base_tbl; @@ -1543,6 +1551,14 @@ UPDATE rw_view SET b = b + 15; UPDATE rw_view SET b = b + 15; -- ok SELECT * FROM foreign_tbl; +-- We don't allow batch insert when there are any WCO constraints +ALTER SERVER loopback OPTIONS (ADD batch_size '10'); +EXPLAIN (VERBOSE, COSTS OFF) +INSERT INTO rw_view VALUES (0, 15), (0, 5); +INSERT INTO rw_view VALUES (0, 15), (0, 5); -- should fail +SELECT * FROM foreign_tbl; +ALTER SERVER loopback OPTIONS (DROP batch_size); + DROP FOREIGN TABLE foreign_tbl CASCADE; DROP TRIGGER row_before_insupd_trigger ON child_tbl; DROP TABLE parent_tbl CASCADE;