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| author | David Rowley <drowley@postgresql.org> | 2024-05-01 13:23:05 +1200 |
|---|---|---|
| committer | David Rowley <drowley@postgresql.org> | 2024-05-01 13:23:05 +1200 |
| commit | 0a34bcd0c23e7f67daad7b026320a12c52d797ac (patch) | |
| tree | 2dc7670da55694fb9ebee35f225486c220861bdd /src/test | |
| parent | 1ee22d1e87b3c442928abe9535d6b2bf8460fc67 (diff) | |
Ensure we allocate NAMEDATALEN bytes for names in Index Only Scans
As an optimization, we store "name" columns as cstrings in btree
indexes.
Here we modify it so that Index Only Scans convert these cstrings back
to names with NAMEDATALEN bytes rather than storing the cstring in the
tuple slot, as was happening previously.
Bug: #17855
Reported-by: Alexander Lakhin
Reviewed-by: Alexander Lakhin, Tom Lane
Discussion: https://postgr.es/m/17855-5f523e0f9769a566@postgresql.org
Backpatch-through: 12, all supported versions
Diffstat (limited to 'src/test')
| -rw-r--r-- | src/test/regress/expected/index_including.out | 25 | ||||
| -rw-r--r-- | src/test/regress/sql/index_including.sql | 19 |
2 files changed, 44 insertions, 0 deletions
diff --git a/src/test/regress/expected/index_including.out b/src/test/regress/expected/index_including.out index 8e5d53e712a..4aacf355821 100644 --- a/src/test/regress/expected/index_including.out +++ b/src/test/regress/expected/index_including.out @@ -399,3 +399,28 @@ Indexes: "tbl_c1_c2_c3_c4_key" UNIQUE CONSTRAINT, btree (c1, c2) INCLUDE (c3, c4) DROP TABLE tbl; +/* + * 10. Test coverage for names stored as cstrings in indexes + */ +CREATE TABLE nametbl (c1 int, c2 name, c3 float); +CREATE INDEX nametbl_c1_c2_idx ON nametbl (c2, c1) INCLUDE (c3); +INSERT INTO nametbl VALUES(1, 'two', 3.0); +VACUUM nametbl; +SET enable_seqscan = 0; +-- Ensure we get an index only scan plan +EXPLAIN (COSTS OFF) SELECT c2, c1, c3 FROM nametbl WHERE c2 = 'two' AND c1 = 1; + QUERY PLAN +---------------------------------------------------- + Index Only Scan using nametbl_c1_c2_idx on nametbl + Index Cond: ((c2 = 'two'::name) AND (c1 = 1)) +(2 rows) + +-- Validate the results look sane +SELECT c2, c1, c3 FROM nametbl WHERE c2 = 'two' AND c1 = 1; + c2 | c1 | c3 +-----+----+---- + two | 1 | 3 +(1 row) + +RESET enable_seqscan; +DROP TABLE nametbl; diff --git a/src/test/regress/sql/index_including.sql b/src/test/regress/sql/index_including.sql index 7e517483adf..880f4bbc421 100644 --- a/src/test/regress/sql/index_including.sql +++ b/src/test/regress/sql/index_including.sql @@ -217,3 +217,22 @@ ALTER TABLE tbl ALTER c1 TYPE bigint; ALTER TABLE tbl ALTER c3 TYPE bigint; \d tbl DROP TABLE tbl; + +/* + * 10. Test coverage for names stored as cstrings in indexes + */ +CREATE TABLE nametbl (c1 int, c2 name, c3 float); +CREATE INDEX nametbl_c1_c2_idx ON nametbl (c2, c1) INCLUDE (c3); +INSERT INTO nametbl VALUES(1, 'two', 3.0); +VACUUM nametbl; +SET enable_seqscan = 0; + +-- Ensure we get an index only scan plan +EXPLAIN (COSTS OFF) SELECT c2, c1, c3 FROM nametbl WHERE c2 = 'two' AND c1 = 1; + +-- Validate the results look sane +SELECT c2, c1, c3 FROM nametbl WHERE c2 = 'two' AND c1 = 1; + +RESET enable_seqscan; + +DROP TABLE nametbl;
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