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mirror of https://github.com/sqlite/sqlite.git synced 2025-08-08 14:02:16 +03:00

Allow WHERE terms to be pushed down into sub-queries that contain window functions, provided that the WHERE term is made up of entirely of constants and copies of expressions found in the PARTITION BY clauses of all window functions in the sub-query.

FossilOrigin-Name: dac51f303bba1a0aac7768c688b0c134deb7641062cce2071d546f2d8f241dec
This commit is contained in:
dan
2021-02-22 20:56:13 +00:00
parent dee1cb3006
commit 903fdd4834
6 changed files with 246 additions and 25 deletions

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@@ -1,5 +1,5 @@
C Add\sa\sfew\ssimple\stest\scases\sfor\sMATERIALIZED\sand\sNOT\sMATERIALIZED.
D 2021-02-22T19:57:58.697
C Allow\sWHERE\sterms\sto\sbe\spushed\sdown\sinto\ssub-queries\sthat\scontain\swindow\sfunctions,\sprovided\sthat\sthe\sWHERE\sterm\sis\smade\sup\sof\sentirely\sof\sconstants\sand\scopies\sof\sexpressions\sfound\sin\sthe\sPARTITION\sBY\sclauses\sof\sall\swindow\sfunctions\sin\sthe\ssub-query.
D 2021-02-22T20:56:13.828
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -542,12 +542,12 @@ F src/printf.c 10e61ec79dd9d41fdc77afee4e0df04fbb427f309c043118fe0b26a7d7db488a
F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
F src/resolve.c c263fa5b255a03314c2418f936386e903d01c3e7cbec25a363a586ef3f10b249
F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
F src/select.c 09f15067366d8276c7444badc82863cae782e241ab1636c4bea8137dc61451e4
F src/select.c 5d66f394afb481eb812927283a3036f7ffbda48442e3a0517d1fa1c3248aca8c
F src/shell.c.in 844417f84df1f6c4fce1c815629a888cfdcf219e86513e9c332bbcc38832f477
F src/sqlite.h.in 8855a19f37ade8dad189a9e48233a2ebe1b46faf469c7eb0906a654e252dcc57
F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
F src/sqlite3ext.h 61b38c073d5e1e96a3d45271b257aef27d0d13da2bea5347692ae579475cd95e
F src/sqliteInt.h d7982229bd90ad5646e9250729125fb2f8a429de965c8825a8e378400e9d3c32
F src/sqliteInt.h 11b9d47e9b9520b123bc75254da7a4e215463e811e62b89518fc5e9a192a0222
F src/sqliteLimit.h d7323ffea5208c6af2734574bae933ca8ed2ab728083caa117c9738581a31657
F src/status.c 4b8bc2a6905163a38b739854a35b826c737333fab5b1f8e03fa7eb9a4799c4c1
F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
@@ -633,7 +633,7 @@ F src/where.c a02138440d7230493b5e508664d629f3e1e7615737a5d83aac3a2955d3a654ff
F src/whereInt.h 446e5e8018f83358ef917cf32d8e6a86dc8430113d0b17e720f1839d3faa44c4
F src/wherecode.c e57a8690311a75d06e723e8d379f9831de04aba300e07174d236e32a7f9c7a13
F src/whereexpr.c 2dc51263e1fb8d8723e97a077a9a137ab0534e59e4cb88b3195f65edbe43cc32
F src/window.c edd6f5e25a1e8f2b6f5305b7f5f7da7bb35f07f0d432b255b1d4c2fcab4205aa
F src/window.c fdf01316f6cecf060378aa1713a29e527ab683823ba7d15b8978ec70165e8bdb
F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
F test/affinity2.test ce1aafc86e110685b324e9a763eab4f2a73f737842ec3b687bd965867de90627
F test/affinity3.test eecb0dabee4b7765a8465439d5e99429279ffba23ca74a7eae270a452799f9e7
@@ -1783,6 +1783,7 @@ F test/windowB.test 7a983ea1cc1cf72be7f378e4b32f6cb2d73014c5cd8b25aaee825164cd42
F test/windowerr.tcl f5acd6fbc210d7b5546c0e879d157888455cd4a17a1d3f28f07c1c8a387019e0
F test/windowerr.test a8b752402109c15aa1c5efe1b93ccb0ce1ef84fa964ae1cd6684dd0b3cc1819b
F test/windowfault.test 72375ae71031eabf96bc88d0af128c8628a091ddc99b5a394e848b3df5fc17ad
F test/windowpushd.test c92a53ac3786d76dbf3ba95b42582c1324f1f1da0c319e670ec620ab5567f822
F test/with1.test 780be387f01e290e768bdfd1827280f9e37ba37223eb4736aba386864fac5a94
F test/with2.test e0030e2f0267a910d6c0e4f46f2dfe941c1cc0d4f659ba69b3597728e7e8f1ab
F test/with3.test 85e059bf4c2ef5626411ee59f399b4bb4b4a0f009bcb7db86f254e570ed11831
@@ -1906,7 +1907,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
P b5a0778cc5a98a864bea72670f83262da940aceb91fa4cdf46ec097337a38a95
R a0e8651539d2046a2eacfb9a26cd3050
U drh
Z 9ff3dc4427ac90918959bed5bdbcba59
P 64878124c160f790bc5861fd799ada03bd7db0c4426b8abc3b7ad1f7aa181168
R e2a54658db8d3d8e6c4194562e3b87a8
T *branch * window-functions-pushdown
T *sym-window-functions-pushdown *
T -sym-trunk *
U dan
Z df00d38ff47c226052c8b6acf25da8b9

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@@ -1 +1 @@
64878124c160f790bc5861fd799ada03bd7db0c4426b8abc3b7ad1f7aa181168
dac51f303bba1a0aac7768c688b0c134deb7641062cce2071d546f2d8f241dec

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@@ -4489,6 +4489,35 @@ static int propagateConstants(
return nChng;
}
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
# if !defined(SQLITE_OMIT_WINDOWFUNC)
/*
** This function is called to determine whether or not it is safe to
** push WHERE clause expression pExpr down to FROM clause sub-query
** pSubq, which contains at least one window function. Return 1
** if it is safe and the expression should be pushed down, or 0
** otherwise.
**
** It is only safe to push the expression down if it consists only
** of constants and copies of expressions that appear in the PARTITION
** BY clause of all window function used by the sub-query. It is safe
** to filter out entire partitions, but not rows within partitions, as
** this may change the results of the window functions.
**
** At the time this function is called it is guaranteed that
**
** * the sub-query uses only one distinct window frame, and
** * that the window frame has a PARTITION BY clase.
*/
static int pushDownWindowCheck(Parse *pParse, Select *pSubq, Expr *pExpr){
assert( pSubq->pWin->pPartition );
assert( (pSubq->selFlags & SF_MultiPart)==0 );
assert( pSubq->pPrior==0 );
return sqlite3ExprIsConstantOrGroupBy(pParse, pExpr, pSubq->pWin->pPartition);
}
# endif /* SQLITE_OMIT_WINDOWFUNC */
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/*
** Make copies of relevant WHERE clause terms of the outer query into
@@ -4536,9 +4565,20 @@ static int propagateConstants(
** But if the (b2=2) term were to be pushed down into the bb subquery,
** then the (1,1,NULL) row would be suppressed.
**
** (6) The inner query features one or more window-functions (since
** changes to the WHERE clause of the inner query could change the
** window over which window functions are calculated).
** (6) Window functions make things tricky as changes to the WHERE clause
** of the inner query could change the window over which window
** functions are calculated. Therefore, do not attempt the optimization
** if:
**
** (6a) The inner query uses multiple incompatible window partitions.
**
** (6b) The inner query is a compound and uses window-functions.
**
** (6c) The WHERE clause does not consist entirely of constants and
** copies of expressions found in the PARTITION BY clause of
** all window-functions used by the sub-query. It is safe to
** filter out entire partitions, as this does not change the
** window over which any window-function is calculated.
**
** (7) The inner query is a Common Table Expression (CTE) that should
** be materialized. (This restriction is implemented in the calling
@@ -4556,13 +4596,17 @@ static int pushDownWhereTerms(
){
Expr *pNew;
int nChng = 0;
Select *pSel;
if( pWhere==0 ) return 0;
if( pSubq->selFlags & SF_Recursive ) return 0; /* restriction (2) */
if( pSubq->selFlags & (SF_Recursive|SF_MultiPart) ) return 0;
#ifndef SQLITE_OMIT_WINDOWFUNC
for(pSel=pSubq; pSel; pSel=pSel->pPrior){
if( pSel->pWin ) return 0; /* restriction (6) */
if( pSubq->pPrior ){
Select *pSel;
for(pSel=pSubq; pSel; pSel=pSel->pPrior){
if( pSel->pWin ) return 0; /* restriction (6b) */
}
}else{
if( pSubq->pWin && pSubq->pWin->pPartition==0 ) return 0;
}
#endif
@@ -4609,6 +4653,14 @@ static int pushDownWhereTerms(
x.isLeftJoin = 0;
x.pEList = pSubq->pEList;
pNew = substExpr(&x, pNew);
#ifndef SQLITE_OMIT_WINDOWFUNC
if( pSubq->pWin && 0==pushDownWindowCheck(pParse, pSubq, pNew) ){
/* Restriction 6c has prevented push-down in this case */
sqlite3ExprDelete(pParse->db, pNew);
nChng--;
break;
}
#endif
if( pSubq->selFlags & SF_Aggregate ){
pSubq->pHaving = sqlite3ExprAnd(pParse, pSubq->pHaving, pNew);
}else{

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@@ -3204,6 +3204,7 @@ struct Select {
#define SF_NoopOrderBy 0x0400000 /* ORDER BY is ignored for this query */
#define SF_UpdateFrom 0x0800000 /* Statement is an UPDATE...FROM */
#define SF_PushDown 0x1000000 /* SELECT has be modified by push-down opt */
#define SF_MultiPart 0x2000000 /* Has multiple incompatible PARTITIONs */
/*
** The results of a SELECT can be distributed in several ways, as defined

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@@ -1304,15 +1304,19 @@ void sqlite3WindowAttach(Parse *pParse, Expr *p, Window *pWin){
** SELECT, or (b) the windows already linked use a compatible window frame.
*/
void sqlite3WindowLink(Select *pSel, Window *pWin){
if( pSel!=0
&& (0==pSel->pWin || 0==sqlite3WindowCompare(0, pSel->pWin, pWin, 0))
){
pWin->pNextWin = pSel->pWin;
if( pSel->pWin ){
pSel->pWin->ppThis = &pWin->pNextWin;
if( pSel ){
if( 0==pSel->pWin || 0==sqlite3WindowCompare(0, pSel->pWin, pWin, 0) ){
pWin->pNextWin = pSel->pWin;
if( pSel->pWin ){
pSel->pWin->ppThis = &pWin->pNextWin;
}
pSel->pWin = pWin;
pWin->ppThis = &pSel->pWin;
}else{
if( sqlite3ExprListCompare(pWin->pPartition, pSel->pWin->pPartition,-1) ){
pSel->selFlags |= SF_MultiPart;
}
}
pSel->pWin = pWin;
pWin->ppThis = &pSel->pWin;
}
}

160
test/windowpushd.test Normal file
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@@ -0,0 +1,160 @@
# 2021 February 23
#
# The author disclaims copyright to this source code. In place of
# a legal notice, here is a blessing:
#
# May you do good and not evil.
# May you find forgiveness for yourself and forgive others.
# May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library. The
# focus of this file is testing the push-down optimization when
# WHERE constraints are pushed down into a sub-query that uses
# window functions.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix windowpushd
do_execsql_test 1.0 {
CREATE TABLE t1(id INTEGER PRIMARY KEY, grp_id);
CREATE INDEX i1 ON t1(grp_id);
CREATE VIEW lll AS SELECT
row_number() OVER (PARTITION BY grp_id),
grp_id, id
FROM t1
}
do_execsql_test 1.1 {
INSERT INTO t1 VALUES
(1, 2), (2, 3), (3, 3), (4, 1), (5, 1),
(6, 1), (7, 1), (8, 1), (9, 3), (10, 3),
(11, 2), (12, 3), (13, 3), (14, 2), (15, 1),
(16, 2), (17, 1), (18, 2), (19, 3), (20, 2)
}
do_execsql_test 1.2 {
SELECT * FROM lll
} {
1 1 4 2 1 5 3 1 6 4 1 7 5 1 8 6 1 15 7 1 17
1 2 1 2 2 11 3 2 14 4 2 16 5 2 18 6 2 20
1 3 2 2 3 3 3 3 9 4 3 10 5 3 12 6 3 13 7 3 19
}
do_execsql_test 1.3 {
SELECT * FROM lll WHERE grp_id=2
} {
1 2 1 2 2 11 3 2 14 4 2 16 5 2 18 6 2 20
}
do_eqp_test 1.4 {
SELECT * FROM lll WHERE grp_id=2
} {SEARCH TABLE t1 USING COVERING INDEX i1 (grp_id=?)}
#-------------------------------------------------------------------------
reset_db
do_execsql_test 2.0 {
CREATE TABLE t1(a, b, c, d);
INSERT INTO t1 VALUES('A', 'C', 1, 0.1);
INSERT INTO t1 VALUES('A', 'D', 2, 0.2);
INSERT INTO t1 VALUES('A', 'E', 3, 0.3);
INSERT INTO t1 VALUES('A', 'C', 4, 0.4);
INSERT INTO t1 VALUES('B', 'D', 5, 0.5);
INSERT INTO t1 VALUES('B', 'E', 6, 0.6);
INSERT INTO t1 VALUES('B', 'C', 7, 0.7);
INSERT INTO t1 VALUES('B', 'D', 8, 0.8);
INSERT INTO t1 VALUES('C', 'E', 9, 0.9);
INSERT INTO t1 VALUES('C', 'C', 10, 1.0);
INSERT INTO t1 VALUES('C', 'D', 11, 1.1);
INSERT INTO t1 VALUES('C', 'E', 12, 1.2);
CREATE INDEX i1 ON t1(a);
CREATE INDEX i2 ON t1(b);
CREATE VIEW v1 AS SELECT a, c, max(c) OVER (PARTITION BY a) FROM t1;
CREATE VIEW v2 AS SELECT a, c,
max(c) OVER (PARTITION BY a),
row_number() OVER ()
FROM t1;
CREATE VIEW v3 AS SELECT b, d,
max(d) OVER (PARTITION BY b),
row_number() OVER (PARTITION BY b)
FROM t1;
}
foreach tn {0 1} {
optimization_control db push-down $tn
do_execsql_test 2.$tn.1.1 {
SELECT * FROM v1;
} {
A 1 4 A 2 4 A 3 4 A 4 4
B 5 8 B 6 8 B 7 8 B 8 8
C 9 12 C 10 12 C 11 12 C 12 12
}
do_execsql_test 2.$tn.1.2 {
SELECT * FROM v1 WHERE a IN ('A', 'B');
} {
A 1 4 A 2 4 A 3 4 A 4 4
B 5 8 B 6 8 B 7 8 B 8 8
}
do_execsql_test 2.$tn.1.3 {
SELECT * FROM v1 WHERE a IS 'C'
} {
C 9 12 C 10 12 C 11 12 C 12 12
}
if {$tn==1} {
do_eqp_test 2.$tn.1.4 {
SELECT * FROM v1 WHERE a IN ('A', 'B');
} {USING INDEX i1 (a=?)}
do_eqp_test 2.$tn.1.5 {
SELECT * FROM v1 WHERE a = 'c' COLLATE nocase
} {USING INDEX i1}
}
do_execsql_test 2.$tn.2.1 {
SELECT * FROM v2;
} {
A 1 4 1 A 2 4 2 A 3 4 3 A 4 4 4
B 5 8 5 B 6 8 6 B 7 8 7 B 8 8 8
C 9 12 9 C 10 12 10 C 11 12 11 C 12 12 12
}
do_execsql_test 2.$tn.2.2 {
SELECT * FROM v2 WHERE a = 'C';
} {
C 9 12 9 C 10 12 10 C 11 12 11 C 12 12 12
}
do_execsql_test 2.$tn.3.1 { SELECT * FROM v3; } {
C 0.1 1.0 1 C 0.4 1.0 2 C 0.7 1.0 3 C 1.0 1.0 4
D 0.2 1.1 1 D 0.5 1.1 2 D 0.8 1.1 3 D 1.1 1.1 4
E 0.3 1.2 1 E 0.6 1.2 2 E 0.9 1.2 3 E 1.2 1.2 4
}
do_execsql_test 2.$tn.3.2 { SELECT * FROM v3 WHERE b<'E' } {
C 0.1 1.0 1 C 0.4 1.0 2 C 0.7 1.0 3 C 1.0 1.0 4
D 0.2 1.1 1 D 0.5 1.1 2 D 0.8 1.1 3 D 1.1 1.1 4
}
if {$tn==1} {
do_eqp_test 2.$tn.3.3 {
SELECT * FROM v3 WHERE b='E'
} {USING INDEX i2 (b=?)}
}
}
finish_test