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[PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops 110+ messages / 5 participants [nested] [flat]
* [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops @ 2019-03-07 20:49 Nikita Glukhov <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Nikita Glukhov @ 2019-03-07 20:49 UTC (permalink / raw) --- doc/src/sgml/spgist.sgml | 1 + src/include/catalog/pg_amop.dat | 4 ++ src/test/regress/expected/box.out | 82 +++++++++++++++++++++++++----- src/test/regress/expected/sanity_check.out | 2 + src/test/regress/sql/box.sql | 70 ++++++++++++++++++++----- 5 files changed, 135 insertions(+), 24 deletions(-) diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml index 7cf9d0e..9070914 100644 --- a/doc/src/sgml/spgist.sgml +++ b/doc/src/sgml/spgist.sgml @@ -139,6 +139,7 @@ <literal>|&></literal> </entry> <entry> + <literal><-></literal> </entry> </row> <row> diff --git a/src/include/catalog/pg_amop.dat b/src/include/catalog/pg_amop.dat index ebc38ae..232557e 100644 --- a/src/include/catalog/pg_amop.dat +++ b/src/include/catalog/pg_amop.dat @@ -1546,6 +1546,10 @@ amopstrategy => '11', amopopr => '|>>(box,box)', amopmethod => 'spgist' }, { amopfamily => 'spgist/box_ops', amoplefttype => 'box', amoprighttype => 'box', amopstrategy => '12', amopopr => '|&>(box,box)', amopmethod => 'spgist' }, +{ amopfamily => 'spgist/box_ops', amoplefttype => 'box', + amoprighttype => 'point', amopstrategy => '15', amoppurpose => 'o', + amopopr => '<->(box,point)', amopmethod => 'spgist', + amopsortfamily => 'btree/float_ops' }, # SP-GiST poly_ops (supports polygons) { amopfamily => 'spgist/poly_ops', amoplefttype => 'polygon', diff --git a/src/test/regress/expected/box.out b/src/test/regress/expected/box.out index 998b522..4d0f169 100644 --- a/src/test/regress/expected/box.out +++ b/src/test/regress/expected/box.out @@ -480,23 +480,33 @@ DROP INDEX box_spgist; -- -- Test the SP-GiST index on the larger volume of data -- -CREATE TABLE quad_box_tbl (b box); +CREATE TABLE quad_box_tbl (id int, b box); INSERT INTO quad_box_tbl - SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) - FROM generate_series(1, 100) x, - generate_series(1, 100) y; + SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) + FROM generate_series(1, 100) x, + generate_series(1, 100) y; -- insert repeating data to test allTheSame INSERT INTO quad_box_tbl - SELECT '((200, 300),(210, 310))' - FROM generate_series(1, 1000); + SELECT i, '((200, 300),(210, 310))' + FROM generate_series(10001, 11000) AS i; INSERT INTO quad_box_tbl - VALUES - (NULL), - (NULL), - ('((-infinity,-infinity),(infinity,infinity))'), - ('((-infinity,100),(-infinity,500))'), - ('((-infinity,-infinity),(700,infinity))'); +VALUES + (11001, NULL), + (11002, NULL), + (11003, '((-infinity,-infinity),(infinity,infinity))'), + (11004, '((-infinity,100),(-infinity,500))'), + (11005, '((-infinity,-infinity),(700,infinity))'); CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b); +-- get reference results for ORDER BY distance from seq scan +SET enable_seqscan = ON; +SET enable_indexscan = OFF; +SET enable_bitmapscan = OFF; +CREATE TABLE quad_box_tbl_ord_seq1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; +CREATE TABLE quad_box_tbl_ord_seq2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; SET enable_seqscan = OFF; SET enable_indexscan = ON; SET enable_bitmapscan = ON; @@ -578,6 +588,54 @@ SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))'; 1 (1 row) +-- test ORDER BY distance +SET enable_indexscan = ON; +SET enable_bitmapscan = OFF; +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + QUERY PLAN +--------------------------------------------------------- + WindowAgg + -> Index Scan using quad_box_tbl_idx on quad_box_tbl + Order By: (b <-> '(123,456)'::point) +(3 rows) + +CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; +SELECT * +FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + n | dist | id | n | dist | id +---+------+----+---+------+---- +(0 rows) + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + QUERY PLAN +--------------------------------------------------------- + WindowAgg + -> Index Scan using quad_box_tbl_idx on quad_box_tbl + Index Cond: (b <@ '(500,600),(200,300)'::box) + Order By: (b <-> '(123,456)'::point) +(4 rows) + +CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; +SELECT * +FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + n | dist | id | n | dist | id +---+------+----+---+------+---- +(0 rows) + RESET enable_seqscan; RESET enable_indexscan; RESET enable_bitmapscan; diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out index 8ff0da1..d6e75ff 100644 --- a/src/test/regress/expected/sanity_check.out +++ b/src/test/regress/expected/sanity_check.out @@ -165,6 +165,8 @@ pg_user_mapping|t point_tbl|t polygon_tbl|t quad_box_tbl|t +quad_box_tbl_ord_seq1|f +quad_box_tbl_ord_seq2|f quad_point_tbl|t quad_poly_tbl|t radix_text_tbl|t diff --git a/src/test/regress/sql/box.sql b/src/test/regress/sql/box.sql index 6710fc9..cd3e002 100644 --- a/src/test/regress/sql/box.sql +++ b/src/test/regress/sql/box.sql @@ -192,28 +192,41 @@ DROP INDEX box_spgist; -- -- Test the SP-GiST index on the larger volume of data -- -CREATE TABLE quad_box_tbl (b box); +CREATE TABLE quad_box_tbl (id int, b box); INSERT INTO quad_box_tbl - SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) - FROM generate_series(1, 100) x, - generate_series(1, 100) y; + SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) + FROM generate_series(1, 100) x, + generate_series(1, 100) y; -- insert repeating data to test allTheSame INSERT INTO quad_box_tbl - SELECT '((200, 300),(210, 310))' - FROM generate_series(1, 1000); + SELECT i, '((200, 300),(210, 310))' + FROM generate_series(10001, 11000) AS i; INSERT INTO quad_box_tbl - VALUES - (NULL), - (NULL), - ('((-infinity,-infinity),(infinity,infinity))'), - ('((-infinity,100),(-infinity,500))'), - ('((-infinity,-infinity),(700,infinity))'); +VALUES + (11001, NULL), + (11002, NULL), + (11003, '((-infinity,-infinity),(infinity,infinity))'), + (11004, '((-infinity,100),(-infinity,500))'), + (11005, '((-infinity,-infinity),(700,infinity))'); CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b); +-- get reference results for ORDER BY distance from seq scan +SET enable_seqscan = ON; +SET enable_indexscan = OFF; +SET enable_bitmapscan = OFF; + +CREATE TABLE quad_box_tbl_ord_seq1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +CREATE TABLE quad_box_tbl_ord_seq2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + SET enable_seqscan = OFF; SET enable_indexscan = ON; SET enable_bitmapscan = ON; @@ -232,6 +245,39 @@ SELECT count(*) FROM quad_box_tbl WHERE b @> box '((201,301),(202,303))'; SELECT count(*) FROM quad_box_tbl WHERE b <@ box '((100,200),(300,500))'; SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))'; +-- test ORDER BY distance +SET enable_indexscan = ON; +SET enable_bitmapscan = OFF; + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +SELECT * +FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + +CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + +SELECT * +FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + RESET enable_seqscan; RESET enable_indexscan; RESET enable_bitmapscan; -- 2.7.4 --------------07EE9595454874974EAD75E7-- ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops @ 2019-03-07 20:49 Nikita Glukhov <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Nikita Glukhov @ 2019-03-07 20:49 UTC (permalink / raw) --- doc/src/sgml/spgist.sgml | 1 + src/include/catalog/pg_amop.dat | 4 ++ src/test/regress/expected/box.out | 82 +++++++++++++++++++++++++----- src/test/regress/expected/sanity_check.out | 2 + src/test/regress/sql/box.sql | 70 ++++++++++++++++++++----- 5 files changed, 135 insertions(+), 24 deletions(-) diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml index 126d1f6..8bc8ad7 100644 --- a/doc/src/sgml/spgist.sgml +++ b/doc/src/sgml/spgist.sgml @@ -139,6 +139,7 @@ <literal>|&></literal> </entry> <entry> + <literal><-></literal> </entry> </row> <row> diff --git a/src/include/catalog/pg_amop.dat b/src/include/catalog/pg_amop.dat index 8e74f86..797223d 100644 --- a/src/include/catalog/pg_amop.dat +++ b/src/include/catalog/pg_amop.dat @@ -1534,6 +1534,10 @@ amopstrategy => '11', amopopr => '|>>(box,box)', amopmethod => 'spgist' }, { amopfamily => 'spgist/box_ops', amoplefttype => 'box', amoprighttype => 'box', amopstrategy => '12', amopopr => '|&>(box,box)', amopmethod => 'spgist' }, +{ amopfamily => 'spgist/box_ops', amoplefttype => 'box', + amoprighttype => 'point', amopstrategy => '15', amoppurpose => 'o', + amopopr => '<->(box,point)', amopmethod => 'spgist', + amopsortfamily => 'btree/float_ops' }, # SP-GiST poly_ops (supports polygons) { amopfamily => 'spgist/poly_ops', amoplefttype => 'polygon', diff --git a/src/test/regress/expected/box.out b/src/test/regress/expected/box.out index 998b522..4d0f169 100644 --- a/src/test/regress/expected/box.out +++ b/src/test/regress/expected/box.out @@ -480,23 +480,33 @@ DROP INDEX box_spgist; -- -- Test the SP-GiST index on the larger volume of data -- -CREATE TABLE quad_box_tbl (b box); +CREATE TABLE quad_box_tbl (id int, b box); INSERT INTO quad_box_tbl - SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) - FROM generate_series(1, 100) x, - generate_series(1, 100) y; + SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) + FROM generate_series(1, 100) x, + generate_series(1, 100) y; -- insert repeating data to test allTheSame INSERT INTO quad_box_tbl - SELECT '((200, 300),(210, 310))' - FROM generate_series(1, 1000); + SELECT i, '((200, 300),(210, 310))' + FROM generate_series(10001, 11000) AS i; INSERT INTO quad_box_tbl - VALUES - (NULL), - (NULL), - ('((-infinity,-infinity),(infinity,infinity))'), - ('((-infinity,100),(-infinity,500))'), - ('((-infinity,-infinity),(700,infinity))'); +VALUES + (11001, NULL), + (11002, NULL), + (11003, '((-infinity,-infinity),(infinity,infinity))'), + (11004, '((-infinity,100),(-infinity,500))'), + (11005, '((-infinity,-infinity),(700,infinity))'); CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b); +-- get reference results for ORDER BY distance from seq scan +SET enable_seqscan = ON; +SET enable_indexscan = OFF; +SET enable_bitmapscan = OFF; +CREATE TABLE quad_box_tbl_ord_seq1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; +CREATE TABLE quad_box_tbl_ord_seq2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; SET enable_seqscan = OFF; SET enable_indexscan = ON; SET enable_bitmapscan = ON; @@ -578,6 +588,54 @@ SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))'; 1 (1 row) +-- test ORDER BY distance +SET enable_indexscan = ON; +SET enable_bitmapscan = OFF; +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + QUERY PLAN +--------------------------------------------------------- + WindowAgg + -> Index Scan using quad_box_tbl_idx on quad_box_tbl + Order By: (b <-> '(123,456)'::point) +(3 rows) + +CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; +SELECT * +FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + n | dist | id | n | dist | id +---+------+----+---+------+---- +(0 rows) + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + QUERY PLAN +--------------------------------------------------------- + WindowAgg + -> Index Scan using quad_box_tbl_idx on quad_box_tbl + Index Cond: (b <@ '(500,600),(200,300)'::box) + Order By: (b <-> '(123,456)'::point) +(4 rows) + +CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; +SELECT * +FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + n | dist | id | n | dist | id +---+------+----+---+------+---- +(0 rows) + RESET enable_seqscan; RESET enable_indexscan; RESET enable_bitmapscan; diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out index aaaa488..850de0c 100644 --- a/src/test/regress/expected/sanity_check.out +++ b/src/test/regress/expected/sanity_check.out @@ -167,6 +167,8 @@ pg_user_mapping|t point_tbl|t polygon_tbl|t quad_box_tbl|t +quad_box_tbl_ord_seq1|f +quad_box_tbl_ord_seq2|f quad_point_tbl|t quad_poly_tbl|t quad_poly_tbl_ord_seq1|f diff --git a/src/test/regress/sql/box.sql b/src/test/regress/sql/box.sql index 6710fc9..cd3e002 100644 --- a/src/test/regress/sql/box.sql +++ b/src/test/regress/sql/box.sql @@ -192,28 +192,41 @@ DROP INDEX box_spgist; -- -- Test the SP-GiST index on the larger volume of data -- -CREATE TABLE quad_box_tbl (b box); +CREATE TABLE quad_box_tbl (id int, b box); INSERT INTO quad_box_tbl - SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) - FROM generate_series(1, 100) x, - generate_series(1, 100) y; + SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) + FROM generate_series(1, 100) x, + generate_series(1, 100) y; -- insert repeating data to test allTheSame INSERT INTO quad_box_tbl - SELECT '((200, 300),(210, 310))' - FROM generate_series(1, 1000); + SELECT i, '((200, 300),(210, 310))' + FROM generate_series(10001, 11000) AS i; INSERT INTO quad_box_tbl - VALUES - (NULL), - (NULL), - ('((-infinity,-infinity),(infinity,infinity))'), - ('((-infinity,100),(-infinity,500))'), - ('((-infinity,-infinity),(700,infinity))'); +VALUES + (11001, NULL), + (11002, NULL), + (11003, '((-infinity,-infinity),(infinity,infinity))'), + (11004, '((-infinity,100),(-infinity,500))'), + (11005, '((-infinity,-infinity),(700,infinity))'); CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b); +-- get reference results for ORDER BY distance from seq scan +SET enable_seqscan = ON; +SET enable_indexscan = OFF; +SET enable_bitmapscan = OFF; + +CREATE TABLE quad_box_tbl_ord_seq1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +CREATE TABLE quad_box_tbl_ord_seq2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + SET enable_seqscan = OFF; SET enable_indexscan = ON; SET enable_bitmapscan = ON; @@ -232,6 +245,39 @@ SELECT count(*) FROM quad_box_tbl WHERE b @> box '((201,301),(202,303))'; SELECT count(*) FROM quad_box_tbl WHERE b <@ box '((100,200),(300,500))'; SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))'; +-- test ORDER BY distance +SET enable_indexscan = ON; +SET enable_bitmapscan = OFF; + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +SELECT * +FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + +CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + +SELECT * +FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + RESET enable_seqscan; RESET enable_indexscan; RESET enable_bitmapscan; -- 2.7.4 --------------B01ADF66983FA504E371CA13-- ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops @ 2019-03-07 20:49 Nikita Glukhov <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Nikita Glukhov @ 2019-03-07 20:49 UTC (permalink / raw) --- doc/src/sgml/spgist.sgml | 1 + src/include/catalog/pg_amop.dat | 4 ++ src/test/regress/expected/box.out | 82 +++++++++++++++++++++++++----- src/test/regress/expected/sanity_check.out | 2 + src/test/regress/sql/box.sql | 70 ++++++++++++++++++++----- 5 files changed, 135 insertions(+), 24 deletions(-) diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml index a816856..81ddf5d 100644 --- a/doc/src/sgml/spgist.sgml +++ b/doc/src/sgml/spgist.sgml @@ -139,6 +139,7 @@ <literal>|&></literal> </entry> <entry> + <literal><-></literal> </entry> </row> <row> diff --git a/src/include/catalog/pg_amop.dat b/src/include/catalog/pg_amop.dat index ebc38ae..232557e 100644 --- a/src/include/catalog/pg_amop.dat +++ b/src/include/catalog/pg_amop.dat @@ -1546,6 +1546,10 @@ amopstrategy => '11', amopopr => '|>>(box,box)', amopmethod => 'spgist' }, { amopfamily => 'spgist/box_ops', amoplefttype => 'box', amoprighttype => 'box', amopstrategy => '12', amopopr => '|&>(box,box)', amopmethod => 'spgist' }, +{ amopfamily => 'spgist/box_ops', amoplefttype => 'box', + amoprighttype => 'point', amopstrategy => '15', amoppurpose => 'o', + amopopr => '<->(box,point)', amopmethod => 'spgist', + amopsortfamily => 'btree/float_ops' }, # SP-GiST poly_ops (supports polygons) { amopfamily => 'spgist/poly_ops', amoplefttype => 'polygon', diff --git a/src/test/regress/expected/box.out b/src/test/regress/expected/box.out index 998b522..4d0f169 100644 --- a/src/test/regress/expected/box.out +++ b/src/test/regress/expected/box.out @@ -480,23 +480,33 @@ DROP INDEX box_spgist; -- -- Test the SP-GiST index on the larger volume of data -- -CREATE TABLE quad_box_tbl (b box); +CREATE TABLE quad_box_tbl (id int, b box); INSERT INTO quad_box_tbl - SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) - FROM generate_series(1, 100) x, - generate_series(1, 100) y; + SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) + FROM generate_series(1, 100) x, + generate_series(1, 100) y; -- insert repeating data to test allTheSame INSERT INTO quad_box_tbl - SELECT '((200, 300),(210, 310))' - FROM generate_series(1, 1000); + SELECT i, '((200, 300),(210, 310))' + FROM generate_series(10001, 11000) AS i; INSERT INTO quad_box_tbl - VALUES - (NULL), - (NULL), - ('((-infinity,-infinity),(infinity,infinity))'), - ('((-infinity,100),(-infinity,500))'), - ('((-infinity,-infinity),(700,infinity))'); +VALUES + (11001, NULL), + (11002, NULL), + (11003, '((-infinity,-infinity),(infinity,infinity))'), + (11004, '((-infinity,100),(-infinity,500))'), + (11005, '((-infinity,-infinity),(700,infinity))'); CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b); +-- get reference results for ORDER BY distance from seq scan +SET enable_seqscan = ON; +SET enable_indexscan = OFF; +SET enable_bitmapscan = OFF; +CREATE TABLE quad_box_tbl_ord_seq1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; +CREATE TABLE quad_box_tbl_ord_seq2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; SET enable_seqscan = OFF; SET enable_indexscan = ON; SET enable_bitmapscan = ON; @@ -578,6 +588,54 @@ SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))'; 1 (1 row) +-- test ORDER BY distance +SET enable_indexscan = ON; +SET enable_bitmapscan = OFF; +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + QUERY PLAN +--------------------------------------------------------- + WindowAgg + -> Index Scan using quad_box_tbl_idx on quad_box_tbl + Order By: (b <-> '(123,456)'::point) +(3 rows) + +CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; +SELECT * +FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + n | dist | id | n | dist | id +---+------+----+---+------+---- +(0 rows) + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + QUERY PLAN +--------------------------------------------------------- + WindowAgg + -> Index Scan using quad_box_tbl_idx on quad_box_tbl + Index Cond: (b <@ '(500,600),(200,300)'::box) + Order By: (b <-> '(123,456)'::point) +(4 rows) + +CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; +SELECT * +FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + n | dist | id | n | dist | id +---+------+----+---+------+---- +(0 rows) + RESET enable_seqscan; RESET enable_indexscan; RESET enable_bitmapscan; diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out index 8ff0da1..d6e75ff 100644 --- a/src/test/regress/expected/sanity_check.out +++ b/src/test/regress/expected/sanity_check.out @@ -165,6 +165,8 @@ pg_user_mapping|t point_tbl|t polygon_tbl|t quad_box_tbl|t +quad_box_tbl_ord_seq1|f +quad_box_tbl_ord_seq2|f quad_point_tbl|t quad_poly_tbl|t radix_text_tbl|t diff --git a/src/test/regress/sql/box.sql b/src/test/regress/sql/box.sql index 6710fc9..cd3e002 100644 --- a/src/test/regress/sql/box.sql +++ b/src/test/regress/sql/box.sql @@ -192,28 +192,41 @@ DROP INDEX box_spgist; -- -- Test the SP-GiST index on the larger volume of data -- -CREATE TABLE quad_box_tbl (b box); +CREATE TABLE quad_box_tbl (id int, b box); INSERT INTO quad_box_tbl - SELECT box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) - FROM generate_series(1, 100) x, - generate_series(1, 100) y; + SELECT (x - 1) * 100 + y, box(point(x * 10, y * 10), point(x * 10 + 5, y * 10 + 5)) + FROM generate_series(1, 100) x, + generate_series(1, 100) y; -- insert repeating data to test allTheSame INSERT INTO quad_box_tbl - SELECT '((200, 300),(210, 310))' - FROM generate_series(1, 1000); + SELECT i, '((200, 300),(210, 310))' + FROM generate_series(10001, 11000) AS i; INSERT INTO quad_box_tbl - VALUES - (NULL), - (NULL), - ('((-infinity,-infinity),(infinity,infinity))'), - ('((-infinity,100),(-infinity,500))'), - ('((-infinity,-infinity),(700,infinity))'); +VALUES + (11001, NULL), + (11002, NULL), + (11003, '((-infinity,-infinity),(infinity,infinity))'), + (11004, '((-infinity,100),(-infinity,500))'), + (11005, '((-infinity,-infinity),(700,infinity))'); CREATE INDEX quad_box_tbl_idx ON quad_box_tbl USING spgist(b); +-- get reference results for ORDER BY distance from seq scan +SET enable_seqscan = ON; +SET enable_indexscan = OFF; +SET enable_bitmapscan = OFF; + +CREATE TABLE quad_box_tbl_ord_seq1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +CREATE TABLE quad_box_tbl_ord_seq2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + SET enable_seqscan = OFF; SET enable_indexscan = ON; SET enable_bitmapscan = ON; @@ -232,6 +245,39 @@ SELECT count(*) FROM quad_box_tbl WHERE b @> box '((201,301),(202,303))'; SELECT count(*) FROM quad_box_tbl WHERE b <@ box '((100,200),(300,500))'; SELECT count(*) FROM quad_box_tbl WHERE b ~= box '((200,300),(205,305))'; +-- test ORDER BY distance +SET enable_indexscan = ON; +SET enable_bitmapscan = OFF; + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +CREATE TEMP TABLE quad_box_tbl_ord_idx1 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl; + +SELECT * +FROM quad_box_tbl_ord_seq1 seq FULL JOIN quad_box_tbl_ord_idx1 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + + +EXPLAIN (COSTS OFF) +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + +CREATE TEMP TABLE quad_box_tbl_ord_idx2 AS +SELECT rank() OVER (ORDER BY b <-> point '123,456') n, b <-> point '123,456' dist, id +FROM quad_box_tbl WHERE b <@ box '((200,300),(500,600))'; + +SELECT * +FROM quad_box_tbl_ord_seq2 seq FULL JOIN quad_box_tbl_ord_idx2 idx + ON seq.n = idx.n AND seq.id = idx.id AND + (seq.dist = idx.dist OR seq.dist IS NULL AND idx.dist IS NULL) +WHERE seq.id IS NULL OR idx.id IS NULL; + RESET enable_seqscan; RESET enable_indexscan; RESET enable_bitmapscan; -- 2.7.4 --------------C466D744B1EAB9FA85D22553-- ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v5 03/12] Add comma for readability @ 2019-03-30 00:37 Justin Pryzby <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Justin Pryzby @ 2019-03-30 00:37 UTC (permalink / raw) --- doc/src/sgml/backup.sgml | 2 +- doc/src/sgml/bki.sgml | 2 +- doc/src/sgml/client-auth.sgml | 4 ++-- doc/src/sgml/config.sgml | 4 ++-- doc/src/sgml/ddl.sgml | 2 +- doc/src/sgml/indices.sgml | 2 +- doc/src/sgml/installation.sgml | 2 +- doc/src/sgml/logical-replication.sgml | 2 +- doc/src/sgml/monitoring.sgml | 8 ++++---- doc/src/sgml/protocol.sgml | 6 +++--- doc/src/sgml/ref/create_table.sgml | 2 +- doc/src/sgml/ref/create_table_as.sgml | 2 +- doc/src/sgml/ref/pgupgrade.sgml | 2 +- doc/src/sgml/ref/psql-ref.sgml | 2 +- doc/src/sgml/sources.sgml | 20 ++++++++++---------- doc/src/sgml/wal.sgml | 2 +- doc/src/sgml/xoper.sgml | 2 +- 17 files changed, 33 insertions(+), 33 deletions(-) diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml index 9d4c000..aba0414 100644 --- a/doc/src/sgml/backup.sgml +++ b/doc/src/sgml/backup.sgml @@ -1024,7 +1024,7 @@ SELECT pg_start_backup('label', true); consider during this backup. </para> <para> - As noted above, if the server crashes during the backup it may not be + As noted above, if the server crashes during the backup, it may not be possible to restart until the <literal>backup_label</literal> file has been manually deleted from the <envar>PGDATA</envar> directory. Note that it is very important to never remove the diff --git a/doc/src/sgml/bki.sgml b/doc/src/sgml/bki.sgml index aa3d6f8..e27fa76 100644 --- a/doc/src/sgml/bki.sgml +++ b/doc/src/sgml/bki.sgml @@ -403,7 +403,7 @@ 8000—9999. This minimizes the risk of OID collisions with other patches being developed concurrently. To keep the 8000—9999 range free for development purposes, after a patch has been committed - to the master git repository its OIDs should be renumbered into + to the master git repository, its OIDs should be renumbered into available space below that range. Typically, this will be done near the end of each development cycle, moving all OIDs consumed by patches committed in that cycle at the same time. The script diff --git a/doc/src/sgml/client-auth.sgml b/doc/src/sgml/client-auth.sgml index 3ed74d8..4a01b1b 100644 --- a/doc/src/sgml/client-auth.sgml +++ b/doc/src/sgml/client-auth.sgml @@ -157,7 +157,7 @@ hostnogssenc <replaceable>database</replaceable> <replaceable>user</replaceable </para> <para> - To make use of this option the server must be built with + To make use of this option, the server must be built with <acronym>SSL</acronym> support. Furthermore, <acronym>SSL</acronym> must be enabled by setting the <xref linkend="guc-ssl"/> configuration parameter (see @@ -189,7 +189,7 @@ hostnogssenc <replaceable>database</replaceable> <replaceable>user</replaceable </para> <para> - To make use of this option the server must be built with + To make use of this option, the server must be built with <acronym>GSSAPI</acronym> support. Otherwise, the <literal>hostgssenc</literal> record is ignored except for logging a warning that it cannot match any connections. diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index ff60875..b898214 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -3458,7 +3458,7 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows reached. The default is <literal>pause</literal>, which means recovery will be paused. <literal>promote</literal> means the recovery process will finish and the server will start to accept connections. - Finally <literal>shutdown</literal> will stop the server after reaching the + Finally, <literal>shutdown</literal> will stop the server after reaching the recovery target. </para> <para> @@ -4188,7 +4188,7 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class=" </para> <para> The delay occurs once the database in recovery has reached a consistent - state, until the standby is promoted or triggered. After that the standby + state, until the standby is promoted or triggered. After that, the standby will end recovery without further waiting. </para> <para> diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index 98cb89f..093ef05 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -3867,7 +3867,7 @@ CREATE INDEX ON measurement (logdate); <title>Partition Maintenance</title> <para> - Normally the set of partitions established when initially defining the + Normally, the set of partitions established when initially defining the table are not intended to remain static. It is common to remove partitions of old data and add partitions for new data. One of the most important advantages of partitioning is diff --git a/doc/src/sgml/indices.sgml b/doc/src/sgml/indices.sgml index 95c0a19..e940ddb 100644 --- a/doc/src/sgml/indices.sgml +++ b/doc/src/sgml/indices.sgml @@ -1081,7 +1081,7 @@ SELECT x FROM tab WHERE x = 'key' AND z < 42; scan. Even in the successful case, this approach trades visibility map accesses for heap accesses; but since the visibility map is four orders of magnitude smaller than the heap it describes, far less physical I/O is - needed to access it. In most situations the visibility map remains + needed to access it. In most situations, the visibility map remains cached in memory all the time. </para> diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml index 4493862..847e028 100644 --- a/doc/src/sgml/installation.sgml +++ b/doc/src/sgml/installation.sgml @@ -2527,7 +2527,7 @@ xcodebuild -version -sdk macosx Path </programlisting> Note that building an extension using a different sysroot version than was used to build the core server is not really recommended; in the - worst case it could result in hard-to-debug ABI inconsistencies. + worst case, it could result in hard-to-debug ABI inconsistencies. </para> <para> diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml index f657d1d..a27ff0b 100644 --- a/doc/src/sgml/logical-replication.sgml +++ b/doc/src/sgml/logical-replication.sgml @@ -201,7 +201,7 @@ <para> Subscriptions are dumped by <command>pg_dump</command> if the current user - is a superuser. Otherwise a warning is written and subscriptions are + is a superuser. Otherwise, a warning is written and subscriptions are skipped, because non-superusers cannot read all subscription information from the <structname>pg_subscription</structname> catalog. </para> diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 728db6b..cba36c0 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -2841,7 +2841,7 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <structname>pg_stat_user_tables</structname> and <structname>pg_stat_sys_tables</structname> views contain the same information, - but filtered to only show user and system tables respectively. + but filtered to only show user and system tables, respectively. </para> <table id="pg-stat-all-indexes-view" xreflabel="pg_stat_all_indexes"> @@ -2908,7 +2908,7 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <structname>pg_stat_user_indexes</structname> and <structname>pg_stat_sys_indexes</structname> views contain the same information, - but filtered to only show user and system indexes respectively. + but filtered to only show user and system indexes, respectively. </para> <para> @@ -3018,7 +3018,7 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <structname>pg_statio_user_tables</structname> and <structname>pg_statio_sys_tables</structname> views contain the same information, - but filtered to only show user and system tables respectively. + but filtered to only show user and system tables, respectively. </para> <table id="pg-statio-all-indexes-view" xreflabel="pg_statio_all_indexes"> @@ -3079,7 +3079,7 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <structname>pg_statio_user_indexes</structname> and <structname>pg_statio_sys_indexes</structname> views contain the same information, - but filtered to only show user and system indexes respectively. + but filtered to only show user and system indexes, respectively. </para> <table id="pg-statio-all-sequences-view" xreflabel="pg_statio_all_sequences"> diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml index 70f7286..3f907f6 100644 --- a/doc/src/sgml/protocol.sgml +++ b/doc/src/sgml/protocol.sgml @@ -1449,7 +1449,7 @@ SELECT 1/0; <literal>S</literal>, perform an <acronym>SSL</acronym> startup handshake (not described here, part of the <acronym>SSL</acronym> specification) with the server. If this is successful, continue - with sending the usual StartupMessage. In this case the + with sending the usual StartupMessage. In this case, the StartupMessage and all subsequent data will be <acronym>SSL</acronym>-encrypted. To continue after <literal>N</literal>, send the usual StartupMessage and proceed without @@ -1462,7 +1462,7 @@ SELECT 1/0; the server predates the addition of <acronym>SSL</acronym> support to <productname>PostgreSQL</productname>. (Such servers are now very ancient, and likely do not exist in the wild anymore.) - In this case the connection must + In this case, the connection must be closed, but the frontend might choose to open a fresh connection and proceed without requesting <acronym>SSL</acronym>. </para> @@ -1528,7 +1528,7 @@ SELECT 1/0; The frontend should also be prepared to handle an ErrorMessage response to GSSENCRequest from the server. This would only occur if the server predates the addition of <acronym>GSSAPI</acronym> encryption - support to <productname>PostgreSQL</productname>. In this case the + support to <productname>PostgreSQL</productname>. In this case, the connection must be closed, but the frontend might choose to open a fresh connection and proceed without requesting <acronym>GSSAPI</acronym> encryption. Given the length limits specified above, the ErrorMessage diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index 9009add..4f3ff1d 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -1189,7 +1189,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM This clause specifies optional storage parameters for a table or index; see <xref linkend="sql-createtable-storage-parameters" endterm="sql-createtable-storage-parameters-title"/> for more - information. For backward-compatibility the <literal>WITH</literal> + information. For backward-compatibility, the <literal>WITH</literal> clause for a table can also include <literal>OIDS=FALSE</literal> to specify that rows of the new table should not contain OIDs (object identifiers), <literal>OIDS=TRUE</literal> is not supported anymore. diff --git a/doc/src/sgml/ref/create_table_as.sgml b/doc/src/sgml/ref/create_table_as.sgml index b5c4ce6..0880459 100644 --- a/doc/src/sgml/ref/create_table_as.sgml +++ b/doc/src/sgml/ref/create_table_as.sgml @@ -142,7 +142,7 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI This clause specifies optional storage parameters for the new table; see <xref linkend="sql-createtable-storage-parameters" endterm="sql-createtable-storage-parameters-title"/> for more - information. For backward-compatibility the <literal>WITH</literal> + information. For backward-compatibility, the <literal>WITH</literal> clause for a table can also include <literal>OIDS=FALSE</literal> to specify that rows of the new table should contain no OIDs (object identifiers), <literal>OIDS=TRUE</literal> is not supported anymore. diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml index 8288676..6a898d9 100644 --- a/doc/src/sgml/ref/pgupgrade.sgml +++ b/doc/src/sgml/ref/pgupgrade.sgml @@ -746,7 +746,7 @@ psql --username=postgres --file=script.sql postgres <application>pg_upgrade</application> launches short-lived postmasters in the old and new data directories. Temporary Unix socket files for communication with these postmasters are, by default, made in the current - working directory. In some situations the path name for the current + working directory. In some situations, the path name for the current directory might be too long to be a valid socket name. In that case you can use the <option>-s</option> option to put the socket files in some directory with a shorter path name. For security, be sure that that diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index 7789fc6..8076495 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -1056,7 +1056,7 @@ testdb=> These operations are not as efficient as the <acronym>SQL</acronym> <command>COPY</command> command with a file or program data source or destination, because all data must pass through the client/server - connection. For large amounts of data the <acronym>SQL</acronym> + connection. For large amounts of data, the <acronym>SQL</acronym> command might be preferable. </para> </tip> diff --git a/doc/src/sgml/sources.sgml b/doc/src/sgml/sources.sgml index b94e7f7..c57f51d 100644 --- a/doc/src/sgml/sources.sgml +++ b/doc/src/sgml/sources.sgml @@ -100,7 +100,7 @@ less -x4 <para> There are two required elements for every message: a severity level (ranging from <literal>DEBUG</literal> to <literal>PANIC</literal>) and a primary - message text. In addition there are optional elements, the most + message text. In addition, there are optional elements, the most common of which is an error identifier code that follows the SQL spec's SQLSTATE conventions. <function>ereport</function> itself is just a shell function that exists @@ -473,7 +473,7 @@ Hint: the addendum <para> Rationale: Messages are not necessarily displayed on terminal-type - displays. In GUI displays or browsers these formatting instructions are + displays. In GUI displays or browsers, these formatting instructions are at best ignored. </para> @@ -884,7 +884,7 @@ BETTER: unrecognized node type: 42 features can be used, if a fallback is provided. </para> <para> - For example <literal>_StaticAssert()</literal> and + For example, <literal>_StaticAssert()</literal> and <literal>__builtin_constant_p</literal> are currently used, even though they are from a newer revision of the C standard and a <productname>GCC</productname> extension, respectively. If not available, in the first case, @@ -897,14 +897,14 @@ BETTER: unrecognized node type: 42 <simplesect> <title>Function-Like Macros and Inline Functions</title> <para> - Both, macros with arguments and <literal>static inline</literal> - functions, may be used. The latter are preferable if there are + Both macros with arguments and <literal>static inline</literal> + functions may be used. The latter are preferable if there are multiple-evaluation hazards when written as a macro, as e.g. the case with <programlisting> #define Max(x, y) ((x) > (y) ? (x) : (y)) </programlisting> - or when the macro would be very long. In other cases it's only + or when the macro would be very long. In other cases, it's only possible to use macros, or at least easier. For example because expressions of various types need to be passed to the macro. </para> @@ -936,16 +936,16 @@ MemoryContextSwitchTo(MemoryContext context) <simplesect> <title>Writing Signal Handlers</title> <para> - To be suitable to run inside a signal handler code has to be + To be suitable to run inside a signal handler, code has to be written very carefully. The fundamental problem is that, unless blocked, a signal handler can interrupt code at any time. If code - inside the signal handler uses the same state as code outside - chaos may ensue. As an example consider what happens if a signal + inside the signal handler uses the same state as code outside, + chaos may ensue. As an example, consider what happens if a signal handler tries to acquire a lock that's already held in the interrupted code. </para> <para> - Barring special arrangements code in signal handlers may only + Barring special arrangements, code in signal handlers may only call async-signal safe functions (as defined in POSIX) and access variables of type <literal>volatile sig_atomic_t</literal>. A few functions in <command>postgres</command> are also deemed signal safe; specifically, diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml index 4eb8feb..30bde24 100644 --- a/doc/src/sgml/wal.sgml +++ b/doc/src/sgml/wal.sgml @@ -326,7 +326,7 @@ before returning a success indication to the client. The client is therefore guaranteed that a transaction reported to be committed will be preserved, even in the event of a server crash immediately after. - However, for short transactions this delay is a major component of the + However, for short transactions, this delay is a major component of the total transaction time. Selecting asynchronous commit mode means that the server returns success as soon as the transaction is logically completed, before the <acronym>WAL</acronym> records it generated have diff --git a/doc/src/sgml/xoper.sgml b/doc/src/sgml/xoper.sgml index 260e43c..55cd3b1 100644 --- a/doc/src/sgml/xoper.sgml +++ b/doc/src/sgml/xoper.sgml @@ -375,7 +375,7 @@ table1.column1 OP table2.column2 Another example is that on machines that meet the <acronym>IEEE</acronym> floating-point standard, negative zero and positive zero are different values (different bit patterns) but they are defined to compare equal. - If a float value might contain negative zero then extra steps are needed + If a float value might contain negative zero, then extra steps are needed to ensure it generates the same hash value as positive zero. </para> -- 2.7.4 --FkmkrVfFsRoUs1wW Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0004-Consistent-language-must-be-superuser.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs). @ 2023-06-25 11:48 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 18 ++++++++-- 3 files changed, 136 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..23ee285b40 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,57 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..c0fc16d773 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. + +<synopsis> +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Jun_25_21_05_09_2023_126)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v1-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs). @ 2023-06-25 11:48 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 18 ++++++++-- 3 files changed, 136 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..23ee285b40 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,57 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..c0fc16d773 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. + +<synopsis> +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Jun_25_21_05_09_2023_126)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v1-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs). @ 2023-06-25 11:48 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 18 ++++++++-- 3 files changed, 136 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..23ee285b40 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,57 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..c0fc16d773 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. + +<synopsis> +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Jun_25_21_05_09_2023_126)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v1-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v1 5/7] Row pattern recognition patch (docs). @ 2023-06-25 11:48 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-25 11:48 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 51 ++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 18 ++++++++-- 3 files changed, 136 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..23ee285b40 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,57 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..c0fc16d773 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,20 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. + +<synopsis> +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Jun_25_21_05_09_2023_126)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v1-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs). @ 2023-06-26 08:05 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++-- 3 files changed, 148 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..e9bbd5bc7c 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jun_26_17_45_07_2023_724)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v2-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs). @ 2023-06-26 08:05 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++-- 3 files changed, 148 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..e9bbd5bc7c 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jun_26_17_45_07_2023_724)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v2-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs). @ 2023-06-26 08:05 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++-- 3 files changed, 148 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..e9bbd5bc7c 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jun_26_17_45_07_2023_724)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v2-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs). @ 2023-06-26 08:05 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++-- 3 files changed, 148 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..e9bbd5bc7c 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jun_26_17_45_07_2023_724)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v2-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v2 5/7] Row pattern recognition patch (docs). @ 2023-06-26 08:05 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-06-26 08:05 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 +++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 69 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++-- 3 files changed, 148 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..e9bbd5bc7c 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Window function <function>rpr</function> can be used with row pattern + common syntax to perform row pattern recognition in a query. Row pattern + common syntax includes two sub clauses. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An + example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, rpr(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5a47ce4343..8069c58ca5 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21648,6 +21648,22 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>rpr</primary> + </indexterm> + <function>rpr</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Perform row pattern recognition using column specified + by <parameter>value</parameter> and returns the value of the column if + current row is the first matching row; + returns <literal>NULL</literal> otherwise. + </para></entry> + </row> </tbody> </tgroup> </table> @@ -21687,6 +21703,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jun_26_17_45_07_2023_724)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v2-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs). @ 2023-07-26 10:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++-- 3 files changed, 133 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index dcc9d6f59d..b333d62410 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Jul_26_21_21_34_2023_317)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v3-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs). @ 2023-07-26 10:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++-- 3 files changed, 133 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index dcc9d6f59d..b333d62410 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Jul_26_21_21_34_2023_317)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v3-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs). @ 2023-07-26 10:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++-- 3 files changed, 133 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index dcc9d6f59d..b333d62410 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Jul_26_21_21_34_2023_317)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v3-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs). @ 2023-07-26 10:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++-- 3 files changed, 133 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index dcc9d6f59d..b333d62410 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Jul_26_21_21_34_2023_317)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v3-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs). @ 2023-07-26 10:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++-- 3 files changed, 133 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index dcc9d6f59d..b333d62410 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Jul_26_21_21_34_2023_317)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v3-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs). @ 2023-08-09 07:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be2f54c914..6cda164522 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Aug__9_17_41_12_2023_134)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v4-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs). @ 2023-08-09 07:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be2f54c914..6cda164522 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Aug__9_17_41_12_2023_134)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v4-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs). @ 2023-08-09 07:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be2f54c914..6cda164522 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Aug__9_17_41_12_2023_134)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v4-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs). @ 2023-08-09 07:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be2f54c914..6cda164522 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Aug__9_17_41_12_2023_134)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v4-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs). @ 2023-08-09 07:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be2f54c914..6cda164522 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Aug__9_17_41_12_2023_134)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v4-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v4 5/7] Row pattern recognition patch (docs). @ 2023-08-09 07:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-08-09 07:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be2f54c914..6cda164522 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21715,6 +21715,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21754,6 +21755,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Aug__9_17_41_12_2023_134)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v4-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs). @ 2023-09-02 06:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0d4b9134..b7bfc9271e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Sep__2_15_52_35_2023_273)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs). @ 2023-09-02 06:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0d4b9134..b7bfc9271e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Sep__2_15_52_35_2023_273)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs). @ 2023-09-02 06:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0d4b9134..b7bfc9271e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Sep__2_15_52_35_2023_273)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs). @ 2023-09-02 06:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0d4b9134..b7bfc9271e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Sep__2_15_52_35_2023_273)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs). @ 2023-09-02 06:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0d4b9134..b7bfc9271e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Sep__2_15_52_35_2023_273)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs). @ 2023-09-02 06:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0d4b9134..b7bfc9271e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Sep__2_15_52_35_2023_273)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs). @ 2023-09-12 05:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Sep_12_15_18_43_2023_359)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs). @ 2023-09-12 05:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Sep_12_15_18_43_2023_359)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs). @ 2023-09-12 05:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Sep_12_15_18_43_2023_359)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs). @ 2023-09-12 05:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Sep_12_15_18_43_2023_359)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs). @ 2023-09-12 05:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Sep_12_15_18_43_2023_359)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v6 5/7] Row pattern recognition patch (docs). @ 2023-09-12 05:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-12 05:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Sep_12_15_18_43_2023_359)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v6-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs). @ 2023-09-22 04:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Sep_22_14_16_40_2023_530)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs). @ 2023-09-22 04:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Sep_22_14_16_40_2023_530)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs). @ 2023-09-22 04:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Sep_22_14_16_40_2023_530)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs). @ 2023-09-22 04:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Sep_22_14_16_40_2023_530)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v7 5/7] Row pattern recognition patch (docs). @ 2023-09-22 04:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-22 04:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Sep_22_14_16_40_2023_530)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs). @ 2023-09-25 05:01 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Sep_25_14_26_30_2023_752)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v8-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs). @ 2023-09-25 05:01 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Sep_25_14_26_30_2023_752)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v8-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs). @ 2023-09-25 05:01 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Sep_25_14_26_30_2023_752)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v8-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs). @ 2023-09-25 05:01 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Sep_25_14_26_30_2023_752)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v8-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v8 5/7] Row pattern recognition patch (docs). @ 2023-09-25 05:01 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 24ad87f910..9c99dda4ae 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..056768b330 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Sep_25_14_26_30_2023_752)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v8-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs). @ 2023-10-04 05:51 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index f1ad64c3d6..6c46ea4355 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Oct__4_15_03_28_2023_821)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v9-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs). @ 2023-10-04 05:51 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index f1ad64c3d6..6c46ea4355 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Oct__4_15_03_28_2023_821)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v9-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs). @ 2023-10-04 05:51 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index f1ad64c3d6..6c46ea4355 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Oct__4_15_03_28_2023_821)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v9-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v9 5/7] Row pattern recognition patch (docs). @ 2023-10-04 05:51 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-04 05:51 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..f39ec8f2d5 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index f1ad64c3d6..6c46ea4355 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21780,6 +21780,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21819,6 +21820,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Oct__4_15_03_28_2023_821)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v9-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs). @ 2023-10-22 02:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7c3e940afe..1d835af15a 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Oct_22_11_39_20_2023_140)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v10-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs). @ 2023-10-22 02:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7c3e940afe..1d835af15a 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Oct_22_11_39_20_2023_140)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v10-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs). @ 2023-10-22 02:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7c3e940afe..1d835af15a 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Oct_22_11_39_20_2023_140)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v10-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v10 5/7] Row pattern recognition patch (docs). @ 2023-10-22 02:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7c3e940afe..1d835af15a 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Oct_22_11_39_20_2023_140)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v10-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v11 5/7] Row pattern recognition patch (docs). @ 2023-11-08 06:57 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-11-08 06:57 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index d963f0a0a0..c3a8167c8e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21933,6 +21933,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21972,6 +21973,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Nov__8_16_37_05_2023_872)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v11-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v11 5/7] Row pattern recognition patch (docs). @ 2023-11-08 06:57 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-11-08 06:57 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index d963f0a0a0..c3a8167c8e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21933,6 +21933,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21972,6 +21973,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Nov__8_16_37_05_2023_872)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v11-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v11 5/7] Row pattern recognition patch (docs). @ 2023-11-08 06:57 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-11-08 06:57 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index d963f0a0a0..c3a8167c8e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21933,6 +21933,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21972,6 +21973,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Nov__8_16_37_05_2023_872)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v11-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v12 5/7] Row pattern recognition patch (docs). @ 2023-12-04 11:23 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-12-04 11:23 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 20da3ed033..8a18e0ee23 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21935,6 +21935,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21974,6 +21975,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 227ba1993b..dabaca9127 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Dec__8_10_16_13_2023_489)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v12-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v12 5/7] Row pattern recognition patch (docs). @ 2023-12-04 11:23 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-12-04 11:23 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 20da3ed033..8a18e0ee23 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21935,6 +21935,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21974,6 +21975,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 227ba1993b..dabaca9127 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Dec__8_10_16_13_2023_489)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v12-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v12 5/7] Row pattern recognition patch (docs). @ 2023-12-04 11:23 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2023-12-04 11:23 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 20da3ed033..8a18e0ee23 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21935,6 +21935,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21974,6 +21975,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 227ba1993b..dabaca9127 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Dec__8_10_16_13_2023_489)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v12-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v13 6/8] Row pattern recognition patch (docs). @ 2024-01-22 09:45 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-01-22 09:45 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 210c7c0b02..8422aa6b93 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21941,6 +21941,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21980,6 +21981,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9917df7839..1575fc2167 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jan_22_19_26_18_2024_011)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v13-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v13 6/8] Row pattern recognition patch (docs). @ 2024-01-22 09:45 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-01-22 09:45 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 210c7c0b02..8422aa6b93 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21941,6 +21941,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21980,6 +21981,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9917df7839..1575fc2167 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jan_22_19_26_18_2024_011)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v13-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v13 6/8] Row pattern recognition patch (docs). @ 2024-01-22 09:45 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-01-22 09:45 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 210c7c0b02..8422aa6b93 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21941,6 +21941,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21980,6 +21981,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9917df7839..1575fc2167 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Jan_22_19_26_18_2024_011)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v13-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v14 6/8] Row pattern recognition patch (docs). @ 2024-02-28 13:59 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-02-28 13:59 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index e5fa82c161..8dd97501a7 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22364,6 +22364,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22403,6 +22404,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9917df7839..1575fc2167 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Feb_29_09_19_54_2024_640)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v14-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v14 6/8] Row pattern recognition patch (docs). @ 2024-02-28 13:59 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-02-28 13:59 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index e5fa82c161..8dd97501a7 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22364,6 +22364,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22403,6 +22404,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9917df7839..1575fc2167 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Feb_29_09_19_54_2024_640)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v14-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v14 6/8] Row pattern recognition patch (docs). @ 2024-02-28 13:59 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-02-28 13:59 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index e5fa82c161..8dd97501a7 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22364,6 +22364,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22403,6 +22404,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9917df7839..1575fc2167 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Feb_29_09_19_54_2024_640)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v14-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs). @ 2024-03-28 10:30 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 93b0bc2bc6..d25eeb3327 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Mar_28_19_59_25_2024_076)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v15-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs). @ 2024-03-28 10:30 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 93b0bc2bc6..d25eeb3327 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Mar_28_19_59_25_2024_076)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v15-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs). @ 2024-03-28 10:30 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 93b0bc2bc6..d25eeb3327 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Mar_28_19_59_25_2024_076)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v15-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs). @ 2024-03-28 10:30 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 93b0bc2bc6..d25eeb3327 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Mar_28_19_59_25_2024_076)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v15-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v15 6/8] Row pattern recognition patch (docs). @ 2024-03-28 10:30 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 93b0bc2bc6..d25eeb3327 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -22637,6 +22637,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -22676,6 +22677,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Mar_28_19_59_25_2024_076)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v15-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v16 6/8] Row pattern recognition patch (docs). @ 2024-04-12 06:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-04-12 06:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 8dfb42ad4d..f6ee99fe19 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23123,6 +23123,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23162,6 +23163,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Apr_12_16_09_08_2024_262)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v16-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v16 6/8] Row pattern recognition patch (docs). @ 2024-04-12 06:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-04-12 06:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 8dfb42ad4d..f6ee99fe19 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23123,6 +23123,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23162,6 +23163,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Apr_12_16_09_08_2024_262)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v16-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v16 6/8] Row pattern recognition patch (docs). @ 2024-04-12 06:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-04-12 06:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 8dfb42ad4d..f6ee99fe19 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23123,6 +23123,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23162,6 +23163,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Apr_12_16_09_08_2024_262)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v16-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v17 6/8] Row pattern recognition patch (docs). @ 2024-04-28 11:00 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-04-28 11:00 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 1928de5762..adbcb1f279 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Apr_28_20_28_26_2024_444)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v17-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v17 6/8] Row pattern recognition patch (docs). @ 2024-04-28 11:00 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-04-28 11:00 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 1928de5762..adbcb1f279 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Apr_28_20_28_26_2024_444)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v17-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v17 6/8] Row pattern recognition patch (docs). @ 2024-04-28 11:00 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-04-28 11:00 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 1928de5762..adbcb1f279 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Apr_28_20_28_26_2024_444)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v17-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v18 6/8] Row pattern recognition patch (docs). @ 2024-05-11 07:11 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-11 07:11 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_May_11_16_23_07_2024_789)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v18-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v18 6/8] Row pattern recognition patch (docs). @ 2024-05-11 07:11 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-11 07:11 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_May_11_16_23_07_2024_789)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v18-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v18 6/8] Row pattern recognition patch (docs). @ 2024-05-11 07:11 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-11 07:11 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_May_11_16_23_07_2024_789)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v18-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v19 6/8] Row pattern recognition patch (docs). @ 2024-05-14 23:26 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-14 23:26 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_May_15_09_02_03_2024_008)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v19-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v19 6/8] Row pattern recognition patch (docs). @ 2024-05-14 23:26 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-14 23:26 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_May_15_09_02_03_2024_008)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v19-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v19 6/8] Row pattern recognition patch (docs). @ 2024-05-14 23:26 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-14 23:26 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_May_15_09_02_03_2024_008)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v19-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v20 6/8] Row pattern recognition patch (docs). @ 2024-05-24 02:26 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-24 02:26 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_May_24_11_39_19_2024_763)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v20-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v20 6/8] Row pattern recognition patch (docs). @ 2024-05-24 02:26 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-24 02:26 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_May_24_11_39_19_2024_763)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v20-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v20 6/8] Row pattern recognition patch (docs). @ 2024-05-24 02:26 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-05-24 02:26 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_May_24_11_39_19_2024_763)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v20-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v21 6/8] Row pattern recognition patch (docs). @ 2024-08-26 04:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-08-26 04:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 461fc3f437..02ad2b0195 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23258,6 +23258,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23297,6 +23298,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Aug_26_13_39_47_2024_878)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v21-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v21 6/8] Row pattern recognition patch (docs). @ 2024-08-26 04:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-08-26 04:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 461fc3f437..02ad2b0195 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23258,6 +23258,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23297,6 +23298,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Aug_26_13_39_47_2024_878)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v21-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v21 6/8] Row pattern recognition patch (docs). @ 2024-08-26 04:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-08-26 04:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 461fc3f437..02ad2b0195 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23258,6 +23258,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23297,6 +23298,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Aug_26_13_39_47_2024_878)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v21-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v22 6/8] Row pattern recognition patch (docs). @ 2024-09-19 04:48 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-09-19 04:48 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 6f75bd0c7d..4482c80a70 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23261,6 +23261,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23300,6 +23301,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Sep_19_13_59_47_2024_608)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v22-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v22 6/8] Row pattern recognition patch (docs). @ 2024-09-19 04:48 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-09-19 04:48 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 6f75bd0c7d..4482c80a70 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23261,6 +23261,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23300,6 +23301,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Sep_19_13_59_47_2024_608)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v22-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v22 6/8] Row pattern recognition patch (docs). @ 2024-09-19 04:48 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-09-19 04:48 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 6f75bd0c7d..4482c80a70 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23261,6 +23261,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23300,6 +23301,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Sep_19_13_59_47_2024_608)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v22-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v23 6/8] Row pattern recognition patch (docs). @ 2024-10-25 03:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-10-25 03:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 58dc06b68b..ef4fa7144f 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23263,6 +23263,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23302,6 +23303,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Oct_25_13_04_53_2024_648)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v23-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v23 6/8] Row pattern recognition patch (docs). @ 2024-10-25 03:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-10-25 03:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 58dc06b68b..ef4fa7144f 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23263,6 +23263,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23302,6 +23303,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Oct_25_13_04_53_2024_648)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v23-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v23 6/8] Row pattern recognition patch (docs). @ 2024-10-25 03:56 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-10-25 03:56 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 58dc06b68b..ef4fa7144f 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23263,6 +23263,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23302,6 +23303,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Fri_Oct_25_13_04_53_2024_648)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v23-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v24 6/8] Row pattern recognition patch (docs). @ 2024-12-19 06:06 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-19 06:06 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Dec_19_15_19_50_2024_894)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v24-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v24 6/8] Row pattern recognition patch (docs). @ 2024-12-19 06:06 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-19 06:06 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Dec_19_15_19_50_2024_894)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v24-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v24 6/8] Row pattern recognition patch (docs). @ 2024-12-19 06:06 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-19 06:06 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Thu_Dec_19_15_19_50_2024_894)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v24-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v25 6/9] Row pattern recognition patch (docs). @ 2024-12-21 06:19 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-21 06:19 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Dec_21_18_20_04_2024_526)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v25-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v25 6/9] Row pattern recognition patch (docs). @ 2024-12-21 06:19 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-21 06:19 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Dec_21_18_20_04_2024_526)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v25-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v25 6/9] Row pattern recognition patch (docs). @ 2024-12-21 06:19 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-21 06:19 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Dec_21_18_20_04_2024_526)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v25-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v26 6/9] Row pattern recognition patch (docs). @ 2024-12-30 12:44 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-30 12:44 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Dec_30_22_37_18_2024_171)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v26-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v26 6/9] Row pattern recognition patch (docs). @ 2024-12-30 12:44 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-30 12:44 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Dec_30_22_37_18_2024_171)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v26-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v26 6/9] Row pattern recognition patch (docs). @ 2024-12-30 12:44 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-30 12:44 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Mon_Dec_30_22_37_18_2024_171)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v26-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v27 6/9] Row pattern recognition patch (docs). @ 2024-12-30 23:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-30 23:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Dec_31_08_57_07_2024_963)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v27-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v27 6/9] Row pattern recognition patch (docs). @ 2024-12-30 23:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-30 23:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Dec_31_08_57_07_2024_963)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v27-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v27 6/9] Row pattern recognition patch (docs). @ 2024-12-30 23:53 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Tatsuo Ishii @ 2024-12-30 23:53 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47370e581a..17a38c4046 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23338,6 +23338,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23377,6 +23378,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index d7089eac0b..7e1c9989ba 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Tue_Dec_31_08_57_07_2024_963)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v27-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v2] remove #include <math.h> where not needed @ 2026-01-15 13:33 Álvaro Herrera <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Álvaro Herrera @ 2026-01-15 13:33 UTC (permalink / raw) Discussion: https://postgr.es/m/[email protected] --- contrib/btree_gist/btree_numeric.c | 1 - contrib/btree_gist/btree_utils_var.c | 1 - contrib/intarray/_intbig_gist.c | 2 -- contrib/ltree/_ltree_gist.c | 2 -- contrib/seg/segparse.y | 1 - src/backend/access/heap/vacuumlazy.c | 2 -- src/backend/access/transam/xlogrecovery.c | 1 - src/backend/access/transam/xlogwait.c | 1 - src/backend/commands/define.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 2 -- src/backend/executor/nodeSubplan.c | 2 -- src/backend/lib/knapsack.c | 1 - src/backend/nodes/readfuncs.c | 2 -- src/backend/optimizer/geqo/geqo_eval.c | 1 - src/backend/optimizer/geqo/geqo_pool.c | 1 - src/backend/optimizer/path/indxpath.c | 2 -- src/backend/optimizer/path/joinpath.c | 2 -- src/backend/optimizer/plan/createplan.c | 2 -- src/backend/optimizer/util/pathnode.c | 2 -- src/backend/statistics/mcv.c | 2 -- src/backend/utils/adt/numutils.c | 1 - src/backend/utils/adt/tid.c | 1 - src/common/binaryheap.c | 2 -- src/include/utils/date.h | 2 -- 24 files changed, 37 deletions(-) diff --git a/contrib/btree_gist/btree_numeric.c b/contrib/btree_gist/btree_numeric.c index 052f27b0794..7ca097abb74 100644 --- a/contrib/btree_gist/btree_numeric.c +++ b/contrib/btree_gist/btree_numeric.c @@ -3,7 +3,6 @@ */ #include "postgres.h" -#include <math.h> #include <float.h> #include "btree_gist.h" diff --git a/contrib/btree_gist/btree_utils_var.c b/contrib/btree_gist/btree_utils_var.c index 40e06ae4908..6847e4e54d5 100644 --- a/contrib/btree_gist/btree_utils_var.c +++ b/contrib/btree_gist/btree_utils_var.c @@ -3,7 +3,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include <float.h> diff --git a/contrib/intarray/_intbig_gist.c b/contrib/intarray/_intbig_gist.c index 0afa8a73b68..6d6ff7413f9 100644 --- a/contrib/intarray/_intbig_gist.c +++ b/contrib/intarray/_intbig_gist.c @@ -3,8 +3,6 @@ */ #include "postgres.h" -#include <math.h> - #include "_int.h" #include "access/gist.h" #include "access/reloptions.h" diff --git a/contrib/ltree/_ltree_gist.c b/contrib/ltree/_ltree_gist.c index ceb92a6304d..6383b37e53f 100644 --- a/contrib/ltree/_ltree_gist.c +++ b/contrib/ltree/_ltree_gist.c @@ -7,8 +7,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/gist.h" #include "access/reloptions.h" #include "access/stratnum.h" diff --git a/contrib/seg/segparse.y b/contrib/seg/segparse.y index 0358ddb182c..a3dbd0cdbd6 100644 --- a/contrib/seg/segparse.y +++ b/contrib/seg/segparse.y @@ -4,7 +4,6 @@ #include "postgres.h" #include <float.h> -#include <math.h> #include "fmgr.h" #include "nodes/miscnodes.h" diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index 2086a577199..1fcb212ab3d 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -129,8 +129,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/genam.h" #include "access/heapam.h" #include "access/htup_details.h" diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c index 0b5f871abe7..117d8d8bb6b 100644 --- a/src/backend/access/transam/xlogrecovery.c +++ b/src/backend/access/transam/xlogrecovery.c @@ -25,7 +25,6 @@ #include "postgres.h" #include <ctype.h> -#include <math.h> #include <time.h> #include <sys/stat.h> #include <sys/time.h> diff --git a/src/backend/access/transam/xlogwait.c b/src/backend/access/transam/xlogwait.c index cab7e5082dc..d286ff63123 100644 --- a/src/backend/access/transam/xlogwait.c +++ b/src/backend/access/transam/xlogwait.c @@ -47,7 +47,6 @@ #include "postgres.h" #include <float.h> -#include <math.h> #include "access/xlog.h" #include "access/xlogrecovery.h" diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c index 8313431397f..4172cc9bacb 100644 --- a/src/backend/commands/define.c +++ b/src/backend/commands/define.c @@ -20,7 +20,6 @@ #include "postgres.h" #include <ctype.h> -#include <math.h> #include "catalog/namespace.h" #include "commands/defrem.h" diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index 2c68327cb29..c68c26cbf38 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -35,8 +35,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/relscan.h" #include "access/tableam.h" #include "access/visibilitymap.h" diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c index 5e510c73926..8285c7101c2 100644 --- a/src/backend/executor/nodeSubplan.c +++ b/src/backend/executor/nodeSubplan.c @@ -26,8 +26,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/htup_details.h" #include "executor/executor.h" #include "executor/nodeSubplan.h" diff --git a/src/backend/lib/knapsack.c b/src/backend/lib/knapsack.c index 1a770b907ec..586f1881fd5 100644 --- a/src/backend/lib/knapsack.c +++ b/src/backend/lib/knapsack.c @@ -24,7 +24,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include "lib/knapsack.h" diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c index c11728c0f17..981ab9c34ef 100644 --- a/src/backend/nodes/readfuncs.c +++ b/src/backend/nodes/readfuncs.c @@ -26,8 +26,6 @@ */ #include "postgres.h" -#include <math.h> - #include "miscadmin.h" #include "nodes/bitmapset.h" #include "nodes/readfuncs.h" diff --git a/src/backend/optimizer/geqo/geqo_eval.c b/src/backend/optimizer/geqo/geqo_eval.c index db2332e2364..56ad3df98fa 100644 --- a/src/backend/optimizer/geqo/geqo_eval.c +++ b/src/backend/optimizer/geqo/geqo_eval.c @@ -23,7 +23,6 @@ #include <float.h> #include <limits.h> -#include <math.h> #include "optimizer/geqo.h" #include "optimizer/joininfo.h" diff --git a/src/backend/optimizer/geqo/geqo_pool.c b/src/backend/optimizer/geqo/geqo_pool.c index fc43406d0c1..f330c739d3d 100644 --- a/src/backend/optimizer/geqo/geqo_pool.c +++ b/src/backend/optimizer/geqo/geqo_pool.c @@ -25,7 +25,6 @@ #include <float.h> #include <limits.h> -#include <math.h> #include "optimizer/geqo_copy.h" #include "optimizer/geqo_pool.h" diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index 51b9d6677d3..29cb60d6b35 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -15,8 +15,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/stratnum.h" #include "access/sysattr.h" #include "access/transam.h" diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c index 7a247493a39..36973eab3be 100644 --- a/src/backend/optimizer/path/joinpath.c +++ b/src/backend/optimizer/path/joinpath.c @@ -14,8 +14,6 @@ */ #include "postgres.h" -#include <math.h> - #include "executor/executor.h" #include "foreign/fdwapi.h" #include "nodes/nodeFuncs.h" diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index af41ca69929..eb4806b084a 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -16,8 +16,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/sysattr.h" #include "catalog/pg_class.h" #include "foreign/fdwapi.h" diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 2e9becf3116..0f12421bac0 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -14,8 +14,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/htup_details.h" #include "executor/nodeSetOp.h" #include "foreign/fdwapi.h" diff --git a/src/backend/statistics/mcv.c b/src/backend/statistics/mcv.c index 9749871b18e..e5ac422c1b4 100644 --- a/src/backend/statistics/mcv.c +++ b/src/backend/statistics/mcv.c @@ -14,8 +14,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/htup_details.h" #include "catalog/pg_statistic_ext.h" #include "catalog/pg_statistic_ext_data.h" diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c index b35e381b0be..47c2e21e6b3 100644 --- a/src/backend/utils/adt/numutils.c +++ b/src/backend/utils/adt/numutils.c @@ -14,7 +14,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include <ctype.h> diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c index c627b385eec..07248b69e57 100644 --- a/src/backend/utils/adt/tid.c +++ b/src/backend/utils/adt/tid.c @@ -17,7 +17,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include "access/sysattr.h" diff --git a/src/common/binaryheap.c b/src/common/binaryheap.c index d2be882e65c..78823ff00f8 100644 --- a/src/common/binaryheap.c +++ b/src/common/binaryheap.c @@ -17,8 +17,6 @@ #include "postgres.h" #endif -#include <math.h> - #ifdef FRONTEND #include "common/logging.h" #endif diff --git a/src/include/utils/date.h b/src/include/utils/date.h index 1c5dfc94ee6..6063810891e 100644 --- a/src/include/utils/date.h +++ b/src/include/utils/date.h @@ -14,8 +14,6 @@ #ifndef DATE_H #define DATE_H -#include <math.h> - #include "datatype/timestamp.h" #include "fmgr.h" #include "pgtime.h" -- 2.47.3 --uzfvjzgwtlw4oib4-- ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v2] remove #include <math.h> where not needed @ 2026-01-15 13:33 Álvaro Herrera <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Álvaro Herrera @ 2026-01-15 13:33 UTC (permalink / raw) Discussion: https://postgr.es/m/[email protected] --- contrib/btree_gist/btree_numeric.c | 1 - contrib/btree_gist/btree_utils_var.c | 1 - contrib/intarray/_intbig_gist.c | 2 -- contrib/ltree/_ltree_gist.c | 2 -- contrib/seg/segparse.y | 1 - src/backend/access/heap/vacuumlazy.c | 2 -- src/backend/access/transam/xlogrecovery.c | 1 - src/backend/access/transam/xlogwait.c | 1 - src/backend/commands/define.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 2 -- src/backend/executor/nodeSubplan.c | 2 -- src/backend/lib/knapsack.c | 1 - src/backend/nodes/readfuncs.c | 2 -- src/backend/optimizer/geqo/geqo_eval.c | 1 - src/backend/optimizer/geqo/geqo_pool.c | 1 - src/backend/optimizer/path/indxpath.c | 2 -- src/backend/optimizer/path/joinpath.c | 2 -- src/backend/optimizer/plan/createplan.c | 2 -- src/backend/optimizer/util/pathnode.c | 2 -- src/backend/statistics/mcv.c | 2 -- src/backend/utils/adt/numutils.c | 1 - src/backend/utils/adt/tid.c | 1 - src/common/binaryheap.c | 2 -- src/include/utils/date.h | 2 -- 24 files changed, 37 deletions(-) diff --git a/contrib/btree_gist/btree_numeric.c b/contrib/btree_gist/btree_numeric.c index 052f27b0794..7ca097abb74 100644 --- a/contrib/btree_gist/btree_numeric.c +++ b/contrib/btree_gist/btree_numeric.c @@ -3,7 +3,6 @@ */ #include "postgres.h" -#include <math.h> #include <float.h> #include "btree_gist.h" diff --git a/contrib/btree_gist/btree_utils_var.c b/contrib/btree_gist/btree_utils_var.c index 40e06ae4908..6847e4e54d5 100644 --- a/contrib/btree_gist/btree_utils_var.c +++ b/contrib/btree_gist/btree_utils_var.c @@ -3,7 +3,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include <float.h> diff --git a/contrib/intarray/_intbig_gist.c b/contrib/intarray/_intbig_gist.c index 0afa8a73b68..6d6ff7413f9 100644 --- a/contrib/intarray/_intbig_gist.c +++ b/contrib/intarray/_intbig_gist.c @@ -3,8 +3,6 @@ */ #include "postgres.h" -#include <math.h> - #include "_int.h" #include "access/gist.h" #include "access/reloptions.h" diff --git a/contrib/ltree/_ltree_gist.c b/contrib/ltree/_ltree_gist.c index ceb92a6304d..6383b37e53f 100644 --- a/contrib/ltree/_ltree_gist.c +++ b/contrib/ltree/_ltree_gist.c @@ -7,8 +7,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/gist.h" #include "access/reloptions.h" #include "access/stratnum.h" diff --git a/contrib/seg/segparse.y b/contrib/seg/segparse.y index 0358ddb182c..a3dbd0cdbd6 100644 --- a/contrib/seg/segparse.y +++ b/contrib/seg/segparse.y @@ -4,7 +4,6 @@ #include "postgres.h" #include <float.h> -#include <math.h> #include "fmgr.h" #include "nodes/miscnodes.h" diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index 2086a577199..1fcb212ab3d 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -129,8 +129,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/genam.h" #include "access/heapam.h" #include "access/htup_details.h" diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c index 0b5f871abe7..117d8d8bb6b 100644 --- a/src/backend/access/transam/xlogrecovery.c +++ b/src/backend/access/transam/xlogrecovery.c @@ -25,7 +25,6 @@ #include "postgres.h" #include <ctype.h> -#include <math.h> #include <time.h> #include <sys/stat.h> #include <sys/time.h> diff --git a/src/backend/access/transam/xlogwait.c b/src/backend/access/transam/xlogwait.c index cab7e5082dc..d286ff63123 100644 --- a/src/backend/access/transam/xlogwait.c +++ b/src/backend/access/transam/xlogwait.c @@ -47,7 +47,6 @@ #include "postgres.h" #include <float.h> -#include <math.h> #include "access/xlog.h" #include "access/xlogrecovery.h" diff --git a/src/backend/commands/define.c b/src/backend/commands/define.c index 8313431397f..4172cc9bacb 100644 --- a/src/backend/commands/define.c +++ b/src/backend/commands/define.c @@ -20,7 +20,6 @@ #include "postgres.h" #include <ctype.h> -#include <math.h> #include "catalog/namespace.h" #include "commands/defrem.h" diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index 2c68327cb29..c68c26cbf38 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -35,8 +35,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/relscan.h" #include "access/tableam.h" #include "access/visibilitymap.h" diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c index 5e510c73926..8285c7101c2 100644 --- a/src/backend/executor/nodeSubplan.c +++ b/src/backend/executor/nodeSubplan.c @@ -26,8 +26,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/htup_details.h" #include "executor/executor.h" #include "executor/nodeSubplan.h" diff --git a/src/backend/lib/knapsack.c b/src/backend/lib/knapsack.c index 1a770b907ec..586f1881fd5 100644 --- a/src/backend/lib/knapsack.c +++ b/src/backend/lib/knapsack.c @@ -24,7 +24,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include "lib/knapsack.h" diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c index c11728c0f17..981ab9c34ef 100644 --- a/src/backend/nodes/readfuncs.c +++ b/src/backend/nodes/readfuncs.c @@ -26,8 +26,6 @@ */ #include "postgres.h" -#include <math.h> - #include "miscadmin.h" #include "nodes/bitmapset.h" #include "nodes/readfuncs.h" diff --git a/src/backend/optimizer/geqo/geqo_eval.c b/src/backend/optimizer/geqo/geqo_eval.c index db2332e2364..56ad3df98fa 100644 --- a/src/backend/optimizer/geqo/geqo_eval.c +++ b/src/backend/optimizer/geqo/geqo_eval.c @@ -23,7 +23,6 @@ #include <float.h> #include <limits.h> -#include <math.h> #include "optimizer/geqo.h" #include "optimizer/joininfo.h" diff --git a/src/backend/optimizer/geqo/geqo_pool.c b/src/backend/optimizer/geqo/geqo_pool.c index fc43406d0c1..f330c739d3d 100644 --- a/src/backend/optimizer/geqo/geqo_pool.c +++ b/src/backend/optimizer/geqo/geqo_pool.c @@ -25,7 +25,6 @@ #include <float.h> #include <limits.h> -#include <math.h> #include "optimizer/geqo_copy.h" #include "optimizer/geqo_pool.h" diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index 51b9d6677d3..29cb60d6b35 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -15,8 +15,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/stratnum.h" #include "access/sysattr.h" #include "access/transam.h" diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c index 7a247493a39..36973eab3be 100644 --- a/src/backend/optimizer/path/joinpath.c +++ b/src/backend/optimizer/path/joinpath.c @@ -14,8 +14,6 @@ */ #include "postgres.h" -#include <math.h> - #include "executor/executor.h" #include "foreign/fdwapi.h" #include "nodes/nodeFuncs.h" diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index af41ca69929..eb4806b084a 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -16,8 +16,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/sysattr.h" #include "catalog/pg_class.h" #include "foreign/fdwapi.h" diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 2e9becf3116..0f12421bac0 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -14,8 +14,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/htup_details.h" #include "executor/nodeSetOp.h" #include "foreign/fdwapi.h" diff --git a/src/backend/statistics/mcv.c b/src/backend/statistics/mcv.c index 9749871b18e..e5ac422c1b4 100644 --- a/src/backend/statistics/mcv.c +++ b/src/backend/statistics/mcv.c @@ -14,8 +14,6 @@ */ #include "postgres.h" -#include <math.h> - #include "access/htup_details.h" #include "catalog/pg_statistic_ext.h" #include "catalog/pg_statistic_ext_data.h" diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c index b35e381b0be..47c2e21e6b3 100644 --- a/src/backend/utils/adt/numutils.c +++ b/src/backend/utils/adt/numutils.c @@ -14,7 +14,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include <ctype.h> diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c index c627b385eec..07248b69e57 100644 --- a/src/backend/utils/adt/tid.c +++ b/src/backend/utils/adt/tid.c @@ -17,7 +17,6 @@ */ #include "postgres.h" -#include <math.h> #include <limits.h> #include "access/sysattr.h" diff --git a/src/common/binaryheap.c b/src/common/binaryheap.c index d2be882e65c..78823ff00f8 100644 --- a/src/common/binaryheap.c +++ b/src/common/binaryheap.c @@ -17,8 +17,6 @@ #include "postgres.h" #endif -#include <math.h> - #ifdef FRONTEND #include "common/logging.h" #endif diff --git a/src/include/utils/date.h b/src/include/utils/date.h index 1c5dfc94ee6..6063810891e 100644 --- a/src/include/utils/date.h +++ b/src/include/utils/date.h @@ -14,8 +14,6 @@ #ifndef DATE_H #define DATE_H -#include <math.h> - #include "datatype/timestamp.h" #include "fmgr.h" #include "pgtime.h" -- 2.47.3 --uzfvjzgwtlw4oib4-- ^ permalink raw reply [nested|flat] 110+ messages in thread
* [PATCH v4 1/4] Make use of pg_popcount() in more places. @ 2026-01-22 17:16 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 110+ messages in thread From: Nathan Bossart @ 2026-01-22 17:16 UTC (permalink / raw) --- src/backend/nodes/bitmapset.c | 27 ++++----------------------- src/include/lib/radixtree.h | 4 ++-- 2 files changed, 6 insertions(+), 25 deletions(-) diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c index a4765876c31..23c91fdb6c9 100644 --- a/src/backend/nodes/bitmapset.c +++ b/src/backend/nodes/bitmapset.c @@ -553,14 +553,8 @@ bms_member_index(Bitmapset *a, int x) bitnum = BITNUM(x); /* count bits in preceding words */ - for (int i = 0; i < wordnum; i++) - { - bitmapword w = a->words[i]; - - /* No need to count the bits in a zero word */ - if (w != 0) - result += bmw_popcount(w); - } + result += pg_popcount((const char *) a->words, + wordnum * sizeof(bitmapword)); /* * Now add bits of the last word, but only those before the item. We can @@ -749,26 +743,13 @@ bms_get_singleton_member(const Bitmapset *a, int *member) int bms_num_members(const Bitmapset *a) { - int result = 0; - int nwords; - int wordnum; - Assert(bms_is_valid_set(a)); if (a == NULL) return 0; - nwords = a->nwords; - wordnum = 0; - do - { - bitmapword w = a->words[wordnum]; - - /* No need to count the bits in a zero word */ - if (w != 0) - result += bmw_popcount(w); - } while (++wordnum < nwords); - return result; + return pg_popcount((const char *) a->words, + a->nwords * sizeof(bitmapword)); } /* diff --git a/src/include/lib/radixtree.h b/src/include/lib/radixtree.h index b223ce10a2d..1425654a67c 100644 --- a/src/include/lib/radixtree.h +++ b/src/include/lib/radixtree.h @@ -2725,8 +2725,8 @@ RT_VERIFY_NODE(RT_NODE * node) /* RT_DUMP_NODE(node); */ - for (int i = 0; i < RT_BM_IDX(RT_NODE_MAX_SLOTS); i++) - cnt += bmw_popcount(n256->isset[i]); + cnt += pg_popcount((const char *) n256->isset, + RT_NODE_MAX_SLOTS / BITS_PER_BYTE); /* * Check if the number of used chunk matches, accounting for -- 2.50.1 (Apple Git-155) --u/0bDz5KPuHk2IF+ Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=v4-0002-Remove-unnecessary-32-bit-optimizations-and-align.patch ^ permalink raw reply [nested|flat] 110+ messages in thread
end of thread, other threads:[~2026-01-22 17:16 UTC | newest] Thread overview: 110+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2019-03-07 20:49 [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops Nikita Glukhov <[email protected]> 2019-03-07 20:49 [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops Nikita Glukhov <[email protected]> 2019-03-07 20:49 [PATCH 3/3] Add operator <->(box, point) to SP-GiST box_ops Nikita Glukhov <[email protected]> 2019-03-30 00:37 [PATCH v5 03/12] Add comma for readability Justin Pryzby <[email protected]> 2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-25 11:48 [PATCH v1 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-06-26 08:05 [PATCH v2 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-08-09 07:56 [PATCH v4 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-12 05:22 [PATCH v6 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-22 04:53 [PATCH v7 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-09-25 05:01 [PATCH v8 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-04 05:51 [PATCH v9 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-11-08 06:57 [PATCH v11 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-11-08 06:57 [PATCH v11 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-11-08 06:57 [PATCH v11 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-12-04 11:23 [PATCH v12 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-12-04 11:23 [PATCH v12 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2023-12-04 11:23 [PATCH v12 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-01-22 09:45 [PATCH v13 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-01-22 09:45 [PATCH v13 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-01-22 09:45 [PATCH v13 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-02-28 13:59 [PATCH v14 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-02-28 13:59 [PATCH v14 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-02-28 13:59 [PATCH v14 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-03-28 10:30 [PATCH v15 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-04-12 06:49 [PATCH v16 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-04-12 06:49 [PATCH v16 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-04-12 06:49 [PATCH v16 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-04-28 11:00 [PATCH v17 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-04-28 11:00 [PATCH v17 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-04-28 11:00 [PATCH v17 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-11 07:11 [PATCH v18 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-11 07:11 [PATCH v18 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-11 07:11 [PATCH v18 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-14 23:26 [PATCH v19 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-14 23:26 [PATCH v19 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-14 23:26 [PATCH v19 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-24 02:26 [PATCH v20 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-24 02:26 [PATCH v20 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-05-24 02:26 [PATCH v20 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-08-26 04:32 [PATCH v21 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-08-26 04:32 [PATCH v21 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-08-26 04:32 [PATCH v21 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-09-19 04:48 [PATCH v22 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-09-19 04:48 [PATCH v22 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-09-19 04:48 [PATCH v22 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-10-25 03:56 [PATCH v23 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-10-25 03:56 [PATCH v23 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-10-25 03:56 [PATCH v23 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-19 06:06 [PATCH v24 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-19 06:06 [PATCH v24 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-19 06:06 [PATCH v24 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-21 06:19 [PATCH v25 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-21 06:19 [PATCH v25 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-21 06:19 [PATCH v25 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-30 12:44 [PATCH v26 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-30 12:44 [PATCH v26 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-30 12:44 [PATCH v26 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-30 23:53 [PATCH v27 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-30 23:53 [PATCH v27 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2024-12-30 23:53 [PATCH v27 6/9] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2026-01-15 13:33 [PATCH v2] remove #include <math.h> where not needed Álvaro Herrera <[email protected]> 2026-01-15 13:33 [PATCH v2] remove #include <math.h> where not needed Álvaro Herrera <[email protected]> 2026-01-22 17:16 [PATCH v4 1/4] Make use of pg_popcount() in more places. Nathan Bossart <[email protected]>
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