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Overview
| Comment: | Try to optimize LIKE and GLOB operators when RHS contains no wildcard. Ticket [e090183531fc274747] |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
613a87d62fd1f8526d53136efae5adae |
| User & Date: | drh 2010-07-22 12:33:57.000 |
Context
|
2010-07-22
| ||
| 15:44 | Add test/threadtest3.c, containing multi-thread tests implemented in C. (check-in: aad88cf54e user: dan tags: trunk) | |
| 12:33 | Try to optimize LIKE and GLOB operators when RHS contains no wildcard. Ticket [e090183531fc274747] (check-in: 613a87d62f user: drh tags: trunk) | |
| 11:40 | Tweaks to the virtual table documentation contained in comments of sqlite3.h. No changes to actual code. (check-in: f5866d4723 user: drh tags: trunk) | |
Changes
Changes to src/where.c.
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685 686 687 688 689 690 691 |
z = pRight->u.zToken;
}
if( z ){
cnt = 0;
while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
cnt++;
}
| | | | 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 |
z = pRight->u.zToken;
}
if( z ){
cnt = 0;
while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
cnt++;
}
if( cnt!=0 && 255!=(u8)z[cnt-1] ){
Expr *pPrefix;
*pisComplete = c==wc[0] && z[cnt+1]==0;
pPrefix = sqlite3Expr(db, TK_STRING, z);
if( pPrefix ) pPrefix->u.zToken[cnt] = 0;
*ppPrefix = pPrefix;
if( op==TK_VARIABLE ){
Vdbe *v = pParse->pVdbe;
sqlite3VdbeSetVarmask(v, pRight->iColumn);
if( *pisComplete && pRight->u.zToken[1] ){
|
| ︙ | ︙ |
Changes to test/analyze3.test.
| ︙ | ︙ | |||
264 265 266 267 268 269 270 271 272 273 274 275 276 277 |
set like "a%"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {101 0 100}
do_test analyze3-2.5 {
set like "%a"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {999 999 100}
#-------------------------------------------------------------------------
# This block of tests checks that statements are correctly marked as
# expired when the values bound to any parameters that may affect the
# query plan are modified.
#
| > > > > > > > > > > > > > > > > | 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 |
set like "a%"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {101 0 100}
do_test analyze3-2.5 {
set like "%a"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {999 999 100}
do_test analyze3-2.6 {
set like "a"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {101 0 0}
do_test analyze3-2.7 {
set like "ab"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {11 0 0}
do_test analyze3-2.8 {
set like "abc"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {2 0 1}
do_test analyze3-2.9 {
set like "a_c"
sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE $like }
} {101 0 10}
#-------------------------------------------------------------------------
# This block of tests checks that statements are correctly marked as
# expired when the values bound to any parameters that may affect the
# query plan are modified.
#
|
| ︙ | ︙ |
Changes to test/like.test.
| ︙ | ︙ | |||
189 190 191 192 193 194 195 196 197 198 199 200 201 202 |
queryplan {
SELECT x FROM t1 WHERE x LIKE 'abc%' ORDER BY 1;
}
} {abc abcd nosort {} i1}
do_test like-3.4 {
set sqlite_like_count
} 0
# Partial optimization when the pattern does not end in '%'
#
do_test like-3.5 {
set sqlite_like_count 0
queryplan {
SELECT x FROM t1 WHERE x LIKE 'a_c' ORDER BY 1;
| > > > > > > > > > > > > > > > > > > > > > > > > > | 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 |
queryplan {
SELECT x FROM t1 WHERE x LIKE 'abc%' ORDER BY 1;
}
} {abc abcd nosort {} i1}
do_test like-3.4 {
set sqlite_like_count
} 0
# The LIKE optimization still works when the RHS is a string with no
# wildcard. Ticket [e090183531fc2747]
#
do_test like-3.4.2 {
queryplan {
SELECT x FROM t1 WHERE x LIKE 'a' ORDER BY 1;
}
} {a nosort {} i1}
do_test like-3.4.3 {
queryplan {
SELECT x FROM t1 WHERE x LIKE 'ab' ORDER BY 1;
}
} {ab nosort {} i1}
do_test like-3.4.4 {
queryplan {
SELECT x FROM t1 WHERE x LIKE 'abcd' ORDER BY 1;
}
} {abcd nosort {} i1}
do_test like-3.4.5 {
queryplan {
SELECT x FROM t1 WHERE x LIKE 'abcde' ORDER BY 1;
}
} {nosort {} i1}
# Partial optimization when the pattern does not end in '%'
#
do_test like-3.5 {
set sqlite_like_count 0
queryplan {
SELECT x FROM t1 WHERE x LIKE 'a_c' ORDER BY 1;
|
| ︙ | ︙ | |||
304 305 306 307 308 309 310 311 312 313 314 315 316 317 |
PRAGMA case_sensitive_like=off;
SELECT x FROM t1 WHERE x GLOB 'a[bc]d' ORDER BY 1;
}
} {abd acd nosort {} i1}
do_test like-3.24 {
set sqlite_like_count
} 6
# No optimization if the LHS of the LIKE is not a column name or
# if the RHS is not a string.
#
do_test like-4.1 {
execsql {PRAGMA case_sensitive_like=on}
set sqlite_like_count 0
| > > > > > > > > > > > > > > > > > > > > | 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 |
PRAGMA case_sensitive_like=off;
SELECT x FROM t1 WHERE x GLOB 'a[bc]d' ORDER BY 1;
}
} {abd acd nosort {} i1}
do_test like-3.24 {
set sqlite_like_count
} 6
# GLOB optimization when there is no wildcard. Ticket [e090183531fc2747]
#
do_test like-3.25 {
queryplan {
SELECT x FROM t1 WHERE x GLOB 'a' ORDER BY 1;
}
} {a nosort {} i1}
do_test like-3.26 {
queryplan {
SELECT x FROM t1 WHERE x GLOB 'abcd' ORDER BY 1;
}
} {abcd nosort {} i1}
do_test like-3.27 {
queryplan {
SELECT x FROM t1 WHERE x GLOB 'abcde' ORDER BY 1;
}
} {nosort {} i1}
# No optimization if the LHS of the LIKE is not a column name or
# if the RHS is not a string.
#
do_test like-4.1 {
execsql {PRAGMA case_sensitive_like=on}
set sqlite_like_count 0
|
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