From 3419d51e1957855f527b94ae983fe8503aafe15c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 4 Aug 2022 14:16:26 -0400 Subject: [PATCH] Fix check_exclusion_or_unique_constraint for UNIQUE NULLS NOT DISTINCT. Adjusting this function was overlooked in commit 94aa7cc5f. The only visible symptom (so far) is that INSERT ... ON CONFLICT could go into an endless loop when inserting a null that has a conflict. Richard Guo and Tom Lane, per bug #17558 from Andrew Kesper Discussion: https://postgr.es/m/17558-3f6599ffcf52fd4a@postgresql.org --- src/backend/executor/execIndexing.c | 18 ++++++++++++------ src/test/regress/expected/constraints.out | 5 +++-- src/test/regress/sql/constraints.sql | 5 +++-- 3 files changed, 18 insertions(+), 10 deletions(-) diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c index 0cb0b8f1111..6a8735edf7f 100644 --- a/src/backend/executor/execIndexing.c +++ b/src/backend/executor/execIndexing.c @@ -699,13 +699,19 @@ check_exclusion_or_unique_constraint(Relation heap, Relation index, } /* - * If any of the input values are NULL, the constraint check is assumed to - * pass (i.e., we assume the operators are strict). + * If any of the input values are NULL, and the index uses the default + * nulls-are-distinct mode, the constraint check is assumed to pass (i.e., + * we assume the operators are strict). Otherwise, we interpret the + * constraint as specifying IS NULL for each column whose input value is + * NULL. */ - for (i = 0; i < indnkeyatts; i++) + if (!indexInfo->ii_NullsNotDistinct) { - if (isnull[i]) - return true; + for (i = 0; i < indnkeyatts; i++) + { + if (isnull[i]) + return true; + } } /* @@ -717,7 +723,7 @@ check_exclusion_or_unique_constraint(Relation heap, Relation index, for (i = 0; i < indnkeyatts; i++) { ScanKeyEntryInitialize(&scankeys[i], - 0, + isnull[i] ? SK_ISNULL | SK_SEARCHNULL : 0, i + 1, constr_strats[i], InvalidOid, diff --git a/src/test/regress/expected/constraints.out b/src/test/regress/expected/constraints.out index 36ccbb5f155..05b7244e4a7 100644 --- a/src/test/regress/expected/constraints.out +++ b/src/test/regress/expected/constraints.out @@ -449,15 +449,16 @@ DROP TABLE UNIQUE_TBL; CREATE TABLE UNIQUE_TBL (i int UNIQUE NULLS NOT DISTINCT, t text); INSERT INTO UNIQUE_TBL VALUES (1, 'one'); INSERT INTO UNIQUE_TBL VALUES (2, 'two'); -INSERT INTO UNIQUE_TBL VALUES (1, 'three'); +INSERT INTO UNIQUE_TBL VALUES (1, 'three'); -- fail ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(1) already exists. INSERT INTO UNIQUE_TBL VALUES (4, 'four'); INSERT INTO UNIQUE_TBL VALUES (5, 'one'); INSERT INTO UNIQUE_TBL (t) VALUES ('six'); -INSERT INTO UNIQUE_TBL (t) VALUES ('seven'); +INSERT INTO UNIQUE_TBL (t) VALUES ('seven'); -- fail ERROR: duplicate key value violates unique constraint "unique_tbl_i_key" DETAIL: Key (i)=(null) already exists. +INSERT INTO UNIQUE_TBL (t) VALUES ('eight') ON CONFLICT DO NOTHING; -- no-op SELECT * FROM UNIQUE_TBL; i | t ---+------ diff --git a/src/test/regress/sql/constraints.sql b/src/test/regress/sql/constraints.sql index 34de0c969ae..833819a32e2 100644 --- a/src/test/regress/sql/constraints.sql +++ b/src/test/regress/sql/constraints.sql @@ -310,11 +310,12 @@ CREATE TABLE UNIQUE_TBL (i int UNIQUE NULLS NOT DISTINCT, t text); INSERT INTO UNIQUE_TBL VALUES (1, 'one'); INSERT INTO UNIQUE_TBL VALUES (2, 'two'); -INSERT INTO UNIQUE_TBL VALUES (1, 'three'); +INSERT INTO UNIQUE_TBL VALUES (1, 'three'); -- fail INSERT INTO UNIQUE_TBL VALUES (4, 'four'); INSERT INTO UNIQUE_TBL VALUES (5, 'one'); INSERT INTO UNIQUE_TBL (t) VALUES ('six'); -INSERT INTO UNIQUE_TBL (t) VALUES ('seven'); +INSERT INTO UNIQUE_TBL (t) VALUES ('seven'); -- fail +INSERT INTO UNIQUE_TBL (t) VALUES ('eight') ON CONFLICT DO NOTHING; -- no-op SELECT * FROM UNIQUE_TBL;