2 files changed, 82 insertions, 0 deletions
diff --git a/src/test/regress/expected/brin.out b/src/test/regress/expected/brin.out
index abfc6746aa8..1f8a817ab24 100644
--- a/src/test/regress/expected/brin.out
+++ b/src/test/regress/expected/brin.out
@@ -418,3 +418,45 @@ SELECT brin_summarize_new_values('brinidx'); -- ok, no change expected
                          0
 (1 row)
 
+-- make sure data are properly de-toasted in BRIN index
+CREATE TABLE brintest_3 (a text, b text, c text, d text);
+-- long random strings (~2000 chars each, so ~6kB for min/max on two
+-- columns) to trigger toasting
+WITH rand_value AS (SELECT string_agg(md5(i::text),'') AS val FROM generate_series(1,60) s(i))
+INSERT INTO brintest_3
+SELECT val, val, val, val FROM rand_value;
+CREATE INDEX brin_test_toast_idx ON brintest_3 USING brin (b, c);
+DELETE FROM brintest_3;
+-- We need to wait a bit for all transactions to complete, so that the
+-- vacuum actually removes the TOAST rows. Creating an index concurrently
+-- is a one way to achieve that, because it does exactly such wait.
+CREATE INDEX CONCURRENTLY brin_test_temp_idx ON brintest_3(a);
+DROP INDEX brin_test_temp_idx;
+-- vacuum the table, to discard TOAST data
+VACUUM brintest_3;
+-- retry insert with a different random-looking (but deterministic) value
+-- the value is different, and so should replace either min or max in the
+-- brin summary
+WITH rand_value AS (SELECT string_agg(md5((-i)::text),'') AS val FROM generate_series(1,60) s(i))
+INSERT INTO brintest_3
+SELECT val, val, val, val FROM rand_value;
+-- now try some queries, accessing the brin index
+SET enable_seqscan = off;
+SET enable_bitmapscan = on;
+EXPLAIN (COSTS OFF)
+SELECT * FROM brintest_3 WHERE b < '0';
+                   QUERY PLAN                   
+------------------------------------------------
+ Bitmap Heap Scan on brintest_3
+   Recheck Cond: (b < '0'::text)
+   ->  Bitmap Index Scan on brin_test_toast_idx
+         Index Cond: (b < '0'::text)
+(4 rows)
+
+SELECT * FROM brintest_3 WHERE b < '0';
+ a | b | c | d 
+---+---+---+---
+(0 rows)
+
+DROP TABLE brintest_3;
+RESET enable_seqscan;
diff --git a/src/test/regress/sql/brin.sql b/src/test/regress/sql/brin.sql
index 7398d12fb74..fb344eb0df2 100644
--- a/src/test/regress/sql/brin.sql
+++ b/src/test/regress/sql/brin.sql
@@ -421,3 +421,43 @@ UPDATE brintest SET textcol = '' WHERE textcol IS NOT NULL;
 SELECT brin_summarize_new_values('brintest'); -- error, not an index
 SELECT brin_summarize_new_values('tenk1_unique1'); -- error, not a BRIN index
 SELECT brin_summarize_new_values('brinidx'); -- ok, no change expected
+
+-- make sure data are properly de-toasted in BRIN index
+CREATE TABLE brintest_3 (a text, b text, c text, d text);
+
+-- long random strings (~2000 chars each, so ~6kB for min/max on two
+-- columns) to trigger toasting
+WITH rand_value AS (SELECT string_agg(md5(i::text),'') AS val FROM generate_series(1,60) s(i))
+INSERT INTO brintest_3
+SELECT val, val, val, val FROM rand_value;
+
+CREATE INDEX brin_test_toast_idx ON brintest_3 USING brin (b, c);
+DELETE FROM brintest_3;
+
+-- We need to wait a bit for all transactions to complete, so that the
+-- vacuum actually removes the TOAST rows. Creating an index concurrently
+-- is a one way to achieve that, because it does exactly such wait.
+CREATE INDEX CONCURRENTLY brin_test_temp_idx ON brintest_3(a);
+DROP INDEX brin_test_temp_idx;
+
+-- vacuum the table, to discard TOAST data
+VACUUM brintest_3;
+
+-- retry insert with a different random-looking (but deterministic) value
+-- the value is different, and so should replace either min or max in the
+-- brin summary
+WITH rand_value AS (SELECT string_agg(md5((-i)::text),'') AS val FROM generate_series(1,60) s(i))
+INSERT INTO brintest_3
+SELECT val, val, val, val FROM rand_value;
+
+-- now try some queries, accessing the brin index
+SET enable_seqscan = off;
+SET enable_bitmapscan = on;
+
+EXPLAIN (COSTS OFF)
+SELECT * FROM brintest_3 WHERE b < '0';
+
+SELECT * FROM brintest_3 WHERE b < '0';
+
+DROP TABLE brintest_3;
+RESET enable_seqscan;