From 9d4ca01314ba0c571139c5560a40ef764ad0feee Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 26 Jan 2017 12:17:47 -0500 Subject: [PATCH] Ensure that a tsquery like '!foo' matches empty tsvectors. !foo means "the tsvector does not contain foo", and therefore it should match an empty tsvector. ts_match_vq() overenthusiastically supposed that an empty tsvector could never match any query, so it forcibly returned FALSE, the wrong answer. Remove the premature optimization. Our behavior on this point was inconsistent, because while seqscans and GIST index searches both failed to match empty tsvectors, GIN index searches would find them, since GIN scans don't rely on ts_match_vq(). That makes this certainly a bug, not a debatable definition disagreement, so back-patch to all supported branches. Report and diagnosis by Tom Dunstan (bug #14515); added test cases by me. Discussion: https://postgr.es/m/20170126025524.1434.97828@wrigleys.postgresql.org --- src/backend/utils/adt/tsvector_op.c | 3 +- src/test/regress/expected/tsearch.out | 137 ++++++++++++++++++++++++++ src/test/regress/expected/tstypes.out | 12 +++ src/test/regress/sql/tsearch.sql | 33 +++++++ src/test/regress/sql/tstypes.sql | 2 + 5 files changed, 186 insertions(+), 1 deletion(-) diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c index f05f913cff..b0f0ce05c5 100644 --- a/src/backend/utils/adt/tsvector_op.c +++ b/src/backend/utils/adt/tsvector_op.c @@ -1927,7 +1927,8 @@ ts_match_vq(PG_FUNCTION_ARGS) CHKVAL chkval; bool result; - if (!val->size || !query->size) + /* empty query matches nothing */ + if (!query->size) { PG_FREE_IF_COPY(val, 0); PG_FREE_IF_COPY(query, 1); diff --git a/src/test/regress/expected/tsearch.out b/src/test/regress/expected/tsearch.out index 0681d43358..b2fc9e207e 100644 --- a/src/test/regress/expected/tsearch.out +++ b/src/test/regress/expected/tsearch.out @@ -98,8 +98,36 @@ SELECT count(*) FROM test_tsvector WHERE a @@ 'w:*|q:*'; 494 (1 row) +SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); + count +------- + 158 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; + count +------- + 0 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; + count +------- + 508 +(1 row) + create index wowidx on test_tsvector using gist (a); SET enable_seqscan=OFF; +SET enable_indexscan=ON; +SET enable_bitmapscan=OFF; +explain (costs off) SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; + QUERY PLAN +------------------------------------------------------- + Aggregate + -> Index Scan using wowidx on test_tsvector + Index Cond: (a @@ '''wr'' | ''qh'''::tsquery) +(3 rows) + SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; count ------- @@ -148,10 +176,107 @@ SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); 158 (1 row) +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; + count +------- + 0 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; + count +------- + 508 +(1 row) + +SET enable_indexscan=OFF; +SET enable_bitmapscan=ON; +explain (costs off) SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; + QUERY PLAN +------------------------------------------------------------- + Aggregate + -> Bitmap Heap Scan on test_tsvector + Recheck Cond: (a @@ '''wr'' | ''qh'''::tsquery) + -> Bitmap Index Scan on wowidx + Index Cond: (a @@ '''wr'' | ''qh'''::tsquery) +(5 rows) + +SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; + count +------- + 158 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ 'wr&qh'; + count +------- + 17 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ 'eq&yt'; + count +------- + 6 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ 'eq|yt'; + count +------- + 98 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ '(eq&yt)|(wr&qh)'; + count +------- + 23 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ '(eq|yt)&(wr|qh)'; + count +------- + 39 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ 'w:*|q:*'; + count +------- + 494 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); + count +------- + 158 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; + count +------- + 0 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; + count +------- + 508 +(1 row) + RESET enable_seqscan; +RESET enable_indexscan; +RESET enable_bitmapscan; DROP INDEX wowidx; CREATE INDEX wowidx ON test_tsvector USING gin (a); SET enable_seqscan=OFF; +-- GIN only supports bitmapscan, so no need to test plain indexscan +explain (costs off) SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; + QUERY PLAN +------------------------------------------------------------- + Aggregate + -> Bitmap Heap Scan on test_tsvector + Recheck Cond: (a @@ '''wr'' | ''qh'''::tsquery) + -> Bitmap Index Scan on wowidx + Index Cond: (a @@ '''wr'' | ''qh'''::tsquery) +(5 rows) + SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; count ------- @@ -200,6 +325,18 @@ SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); 158 (1 row) +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; + count +------- + 0 +(1 row) + +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; + count +------- + 508 +(1 row) + RESET enable_seqscan; INSERT INTO test_tsvector VALUES ('???', 'DFG:1A,2B,6C,10 FGH'); SELECT * FROM ts_stat('SELECT a FROM test_tsvector') ORDER BY ndoc DESC, nentry DESC, word LIMIT 10; diff --git a/src/test/regress/expected/tstypes.out b/src/test/regress/expected/tstypes.out index dcce82fdc4..6272e70e09 100644 --- a/src/test/regress/expected/tstypes.out +++ b/src/test/regress/expected/tstypes.out @@ -773,6 +773,18 @@ select to_tsvector('simple', 'x y q y') @@ '!x <-> y' AS "true"; t (1 row) +select to_tsvector('simple', 'x y q y') @@ '!foo' AS "true"; + true +------ + t +(1 row) + +select to_tsvector('simple', '') @@ '!foo' AS "true"; + true +------ + t +(1 row) + --ranking SELECT ts_rank(' a:1 s:2C d g'::tsvector, 'a | s'); ts_rank diff --git a/src/test/regress/sql/tsearch.sql b/src/test/regress/sql/tsearch.sql index 1255f6954d..e4b21f8f18 100644 --- a/src/test/regress/sql/tsearch.sql +++ b/src/test/regress/sql/tsearch.sql @@ -48,10 +48,17 @@ SELECT count(*) FROM test_tsvector WHERE a @@ 'eq|yt'; SELECT count(*) FROM test_tsvector WHERE a @@ '(eq&yt)|(wr&qh)'; SELECT count(*) FROM test_tsvector WHERE a @@ '(eq|yt)&(wr|qh)'; SELECT count(*) FROM test_tsvector WHERE a @@ 'w:*|q:*'; +SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; create index wowidx on test_tsvector using gist (a); SET enable_seqscan=OFF; +SET enable_indexscan=ON; +SET enable_bitmapscan=OFF; + +explain (costs off) SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; SELECT count(*) FROM test_tsvector WHERE a @@ 'wr&qh'; @@ -61,14 +68,37 @@ SELECT count(*) FROM test_tsvector WHERE a @@ '(eq&yt)|(wr&qh)'; SELECT count(*) FROM test_tsvector WHERE a @@ '(eq|yt)&(wr|qh)'; SELECT count(*) FROM test_tsvector WHERE a @@ 'w:*|q:*'; SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; + +SET enable_indexscan=OFF; +SET enable_bitmapscan=ON; + +explain (costs off) SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; + +SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; +SELECT count(*) FROM test_tsvector WHERE a @@ 'wr&qh'; +SELECT count(*) FROM test_tsvector WHERE a @@ 'eq&yt'; +SELECT count(*) FROM test_tsvector WHERE a @@ 'eq|yt'; +SELECT count(*) FROM test_tsvector WHERE a @@ '(eq&yt)|(wr&qh)'; +SELECT count(*) FROM test_tsvector WHERE a @@ '(eq|yt)&(wr|qh)'; +SELECT count(*) FROM test_tsvector WHERE a @@ 'w:*|q:*'; +SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; RESET enable_seqscan; +RESET enable_indexscan; +RESET enable_bitmapscan; DROP INDEX wowidx; CREATE INDEX wowidx ON test_tsvector USING gin (a); SET enable_seqscan=OFF; +-- GIN only supports bitmapscan, so no need to test plain indexscan + +explain (costs off) SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; SELECT count(*) FROM test_tsvector WHERE a @@ 'wr|qh'; SELECT count(*) FROM test_tsvector WHERE a @@ 'wr&qh'; @@ -78,8 +108,11 @@ SELECT count(*) FROM test_tsvector WHERE a @@ '(eq&yt)|(wr&qh)'; SELECT count(*) FROM test_tsvector WHERE a @@ '(eq|yt)&(wr|qh)'; SELECT count(*) FROM test_tsvector WHERE a @@ 'w:*|q:*'; SELECT count(*) FROM test_tsvector WHERE a @@ any ('{wr,qh}'); +SELECT count(*) FROM test_tsvector WHERE a @@ 'no_such_lexeme'; +SELECT count(*) FROM test_tsvector WHERE a @@ '!no_such_lexeme'; RESET enable_seqscan; + INSERT INTO test_tsvector VALUES ('???', 'DFG:1A,2B,6C,10 FGH'); SELECT * FROM ts_stat('SELECT a FROM test_tsvector') ORDER BY ndoc DESC, nentry DESC, word LIMIT 10; SELECT * FROM ts_stat('SELECT a FROM test_tsvector', 'AB') ORDER BY ndoc DESC, nentry DESC, word; diff --git a/src/test/regress/sql/tstypes.sql b/src/test/regress/sql/tstypes.sql index 77436ce04e..0a40ec9350 100644 --- a/src/test/regress/sql/tstypes.sql +++ b/src/test/regress/sql/tstypes.sql @@ -145,6 +145,8 @@ select to_tsvector('simple', 'x q') @@ '(x | y <-> !z) <-> q' AS "true"; select to_tsvector('simple', 'x q') @@ '(!x | y <-> z) <-> q' AS "false"; select to_tsvector('simple', 'z q') @@ '(!x | y <-> z) <-> q' AS "true"; select to_tsvector('simple', 'x y q y') @@ '!x <-> y' AS "true"; +select to_tsvector('simple', 'x y q y') @@ '!foo' AS "true"; +select to_tsvector('simple', '') @@ '!foo' AS "true"; --ranking SELECT ts_rank(' a:1 s:2C d g'::tsvector, 'a | s');