From 9d713d2e99017f8e3c17d3f41eaf08c4daa9aeec Mon Sep 17 00:00:00 2001 From: Tomas Vondra Date: Fri, 30 Oct 2026 16:27:05 +0100 Subject: [PATCH vmaster 3/4] Fix BRIN minmax-multi distance calculation for OID The oid_minmax_multi_ops opclass simply calculated the distance using brin_minmax_multi_distance_int4. That however interprets the values as int32, so OIDs above PG_INT32_MAX were treated as negative values, and ranges crossing the boundary ended with a negative distance. With assert-enabled guild, this tripped the (a1 <= a2) check. Without asserts, the index was less efficient. Fix by introducing brin_minmax_multi_distance_oid, correctly treating the OID values as unsigned. This required a catalog change (and catversion bump), so it can't be backpatched. It'd be possible to adjust brin_minmax_multi_distance_int4 to handle the (a1 > a2) case differently. But that'd lose the assert, and it does not seem worth it (indexes on OIDs don't seem very common). Author: Tomas Vondra Discussion: https://postgr.es/m/CALdSSPgBvXz-VSF0p-5k%3D_uFfN38cWrERmm_AC4K67N6MWQhmg%40mail.gmail.com --- src/backend/access/brin/brin_minmax_multi.c | 21 +++++++++++++++++++++ src/include/catalog/pg_amproc.dat | 2 +- src/include/catalog/pg_proc.dat | 4 ++++ src/test/regress/expected/brin_multi.out | 5 +++++ src/test/regress/sql/brin_multi.sql | 8 ++++++++ 5 files changed, 39 insertions(+), 1 deletion(-) diff --git a/src/backend/access/brin/brin_minmax_multi.c b/src/backend/access/brin/brin_minmax_multi.c index 08e68cb48f4..89b78d726e9 100644 --- a/src/backend/access/brin/brin_minmax_multi.c +++ b/src/backend/access/brin/brin_minmax_multi.c @@ -1982,6 +1982,27 @@ brin_minmax_multi_distance_int8(PG_FUNCTION_ARGS) PG_RETURN_FLOAT8((double) a2 - (double) a1); } +/* + * Compute the distance between two oid values (plain subtraction). + * + * OIDs are unsigned, so we can't use the int4 function - values above + * PG_INT32_MAX would be interpreted as negative, breaking the ordering. + */ +Datum +brin_minmax_multi_distance_oid(PG_FUNCTION_ARGS) +{ + Oid a1 = PG_GETARG_OID(0); + Oid a2 = PG_GETARG_OID(1); + + /* + * We know the values are range boundaries, but the range may be collapsed + * (i.e. single points), with equal values. + */ + Assert(a1 <= a2); + + PG_RETURN_FLOAT8((double) a2 - (double) a1); +} + /* * Compute the distance between two tid values (by mapping them to float8 and * then subtracting them). diff --git a/src/include/catalog/pg_amproc.dat b/src/include/catalog/pg_amproc.dat index 27fb8cd2d35..4b83b6eccd8 100644 --- a/src/include/catalog/pg_amproc.dat +++ b/src/include/catalog/pg_amproc.dat @@ -1129,7 +1129,7 @@ amproc => 'brin_minmax_multi_options' }, { amprocfamily => 'brin/oid_minmax_multi_ops', amproclefttype => 'oid', amprocrighttype => 'oid', amprocnum => '11', - amproc => 'brin_minmax_multi_distance_int4' }, + amproc => 'brin_minmax_multi_distance_oid' }, # bloom oid { amprocfamily => 'brin/oid_bloom_ops', amproclefttype => 'oid', diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 1f21a8eb6d4..e9c0e3937cb 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -9157,6 +9157,10 @@ proname => 'brin_minmax_multi_distance_numeric', prorettype => 'float8', proargtypes => 'internal internal', prosrc => 'brin_minmax_multi_distance_numeric' }, +{ oid => '9126', descr => 'BRIN multi minmax oid distance', + proname => 'brin_minmax_multi_distance_oid', prorettype => 'float8', + proargtypes => 'internal internal', + prosrc => 'brin_minmax_multi_distance_oid' }, { oid => '4627', descr => 'BRIN multi minmax tid distance', proname => 'brin_minmax_multi_distance_tid', prorettype => 'float8', proargtypes => 'internal internal', diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out index 300abc2e1ab..ff9f0c39774 100644 --- a/src/test/regress/expected/brin_multi.out +++ b/src/test/regress/expected/brin_multi.out @@ -991,3 +991,8 @@ TRUNCATE brin_overflow_test; INSERT INTO brin_overflow_test VALUES (1), (1e500); CREATE INDEX ON brin_overflow_test USING brin (n numeric_minmax_multi_ops); DROP TABLE brin_overflow_test; +-- OID values should not be treated as negative int4 values +CREATE TABLE brin_oid_overflow_test (o oid); +INSERT INTO brin_oid_overflow_test VALUES (1), (3000000000); +CREATE INDEX ON brin_oid_overflow_test USING brin (o oid_minmax_multi_ops); +DROP TABLE brin_oid_overflow_test; diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql index 2cbdff00047..445ba1d718a 100644 --- a/src/test/regress/sql/brin_multi.sql +++ b/src/test/regress/sql/brin_multi.sql @@ -718,3 +718,11 @@ INSERT INTO brin_overflow_test VALUES (1), (1e500); CREATE INDEX ON brin_overflow_test USING brin (n numeric_minmax_multi_ops); DROP TABLE brin_overflow_test; + +-- OID values should not be treated as negative int4 values +CREATE TABLE brin_oid_overflow_test (o oid); + +INSERT INTO brin_oid_overflow_test VALUES (1), (3000000000); +CREATE INDEX ON brin_oid_overflow_test USING brin (o oid_minmax_multi_ops); + +DROP TABLE brin_oid_overflow_test; -- 2.55.0