/usr/lib/mysql-testsuite/t/key.test is in mysql-testsuite-5.6 5.6.16-1~exp1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 | --disable_warnings
drop table if exists t1,t2,t3;
--enable_warnings
SET SQL_WARNINGS=1;
#
# This failed for Elizabeth Mattijsen
#
CREATE TABLE t1 (
ID CHAR(32) NOT NULL,
name CHAR(32) NOT NULL,
value CHAR(255),
INDEX indexIDname (ID(8),name(8))
) ;
INSERT INTO t1 VALUES
('keyword','indexdir','/export/home/local/www/database/indexes/keyword');
INSERT INTO t1 VALUES ('keyword','urlprefix','text/ /text');
INSERT INTO t1 VALUES ('keyword','urlmap','/text/ /');
INSERT INTO t1 VALUES ('keyword','attr','personal employee company');
INSERT INTO t1 VALUES
('emailgids','indexdir','/export/home/local/www/database/indexes/emailgids');
INSERT INTO t1 VALUES ('emailgids','urlprefix','text/ /text');
INSERT INTO t1 VALUES ('emailgids','urlmap','/text/ /');
INSERT INTO t1 VALUES ('emailgids','attr','personal employee company');
SELECT value FROM t1 WHERE ID='emailgids' AND name='attr';
drop table t1;
#
# Problem with many key parts and many or
#
CREATE TABLE t1 (
price int(5) DEFAULT '0' NOT NULL,
area varchar(40) DEFAULT '' NOT NULL,
type varchar(40) DEFAULT '' NOT NULL,
transityes enum('Y','N') DEFAULT 'Y' NOT NULL,
shopsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
schoolsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
petsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
KEY price (price,area,type,transityes,shopsyes,schoolsyes,petsyes)
);
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','N','N','N','N');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','N','N','N','N');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','','','','');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
SELECT * FROM t1 WHERE area='Vancouver' and transityes='y' and schoolsyes='y' and ( ((type='1 Bedroom' or type='Studio/Bach') and (price<=500)) or ((type='2 Bedroom') and (price<=550)) or ((type='Shared/Roomate') and (price<=300)) or ((type='Room and Board') and (price<=500)) ) and price <= 400;
drop table t1;
#
# No longer a problem with primary key
#
CREATE TABLE t1 (program enum('signup','unique','sliding') not null, type enum('basic','sliding','signup'), sites set('mt'), PRIMARY KEY (program));
# This no longer give an error for wrong primary key
ALTER TABLE t1 modify program enum('signup','unique','sliding');
drop table t1;
#
# Test of compressed decimal index.
#
CREATE TABLE t1 (
name varchar(50) DEFAULT '' NOT NULL,
author varchar(50) DEFAULT '' NOT NULL,
category decimal(10,0) DEFAULT '0' NOT NULL,
email varchar(50),
password varchar(50),
proxy varchar(50),
bitmap varchar(20),
msg varchar(255),
urlscol varchar(127),
urlhttp varchar(127),
timeout decimal(10,0),
nbcnx decimal(10,0),
creation decimal(10,0),
livinguntil decimal(10,0),
lang decimal(10,0),
type decimal(10,0),
subcat decimal(10,0),
subtype decimal(10,0),
reg char(1),
scs varchar(255),
capacity decimal(10,0),
userISP varchar(50),
CCident varchar(50) DEFAULT '' NOT NULL,
PRIMARY KEY (name,author,category)
);
INSERT INTO t1 VALUES
('patnom','patauteur',0,'p.favre@cryo-networks.fr',NULL,NULL,'#p2sndnq6ae5g1u6t','essai salut','scol://195.242.78.119:patauteur.patnom',NULL,NULL,NULL,950036174,-882087474,NULL,3,0,3,'1','Pub/patnom/futur_divers.scs',NULL,'pat','CC1');
INSERT INTO t1 VALUES
('LeNomDeMonSite','Marc',0,'m.barilley@cryo-networks.fr',NULL,NULL,NULL,NULL,'scol://195.242.78.119:Marc.LeNomDeMonSite',NULL,NULL,NULL,950560434,-881563214,NULL,3,0,3,'1','Pub/LeNomDeMonSite/domus_hibere.scs',NULL,'Marq','CC1');
select * from t1 where name='patnom' and author='patauteur' and category=0;
drop table t1;
#
# Problem with search on partial index
#
create table t1
(
name_id int not null auto_increment,
name blob,
INDEX name_idx (name(5)),
primary key (name_id)
);
INSERT t1 VALUES(NULL,'/');
INSERT t1 VALUES(NULL,'[T,U]_axpby');
SELECT * FROM t1 WHERE name='[T,U]_axpy';
SELECT * FROM t1 WHERE name='[T,U]_axpby';
create table t2
(
name_id int not null auto_increment,
name char(255) binary,
INDEX name_idx (name(5)),
primary key (name_id)
);
INSERT t2 select * from t1;
SELECT * FROM t2 WHERE name='[T,U]_axpy';
SELECT * FROM t2 WHERE name='[T,U]_axpby';
# Test possible problems with warnings in CREATE ... SELECT
CREATE TABLE t3 SELECT * FROM t2 WHERE name='[T,U]_axpby';
SELECT * FROM t2 WHERE name='[T,U]_axpby';
drop table t1,t2,t3;
#
# Test bug with long primary key
#
create table t1
(
SEQNO numeric(12 ) not null,
MOTYPEID numeric(12 ) not null,
MOINSTANCEID numeric(12 ) not null,
ATTRID numeric(12 ) not null,
VALUE varchar(120) not null,
primary key (SEQNO, MOTYPEID, MOINSTANCEID, ATTRID, VALUE )
);
INSERT INTO t1 VALUES (1, 1, 1, 1, 'a');
INSERT INTO t1 VALUES (1, 1, 1, 1, 'b');
--error ER_DUP_ENTRY
INSERT INTO t1 VALUES (1, 1, 1, 1, 'a');
drop table t1;
#
# Test with blob + tinyint key
# (Failed for Greg Valure)
#
CREATE TABLE t1 (
a tinytext NOT NULL,
b tinyint(3) unsigned NOT NULL default '0',
PRIMARY KEY (a(32),b)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('a',1),('a',2);
SELECT * FROM t1 WHERE a='a' AND b=2;
SELECT * FROM t1 WHERE a='a' AND b in (2);
SELECT * FROM t1 WHERE a='a' AND b in (1,2);
drop table t1;
#
# Test of create key order
#
create table t1 (a int not null unique, b int unique, c int, d int not null primary key, key(c), e int not null unique);
show keys from t1;
drop table t1;
#
# Problem with UNIQUE() with NULL parts and auto increment
#
CREATE TABLE t1 (c CHAR(10) NOT NULL,i INT NOT NULL AUTO_INCREMENT,
UNIQUE (c,i));
INSERT INTO t1 (c) VALUES (NULL),(NULL);
SELECT * FROM t1;
INSERT INTO t1 (c) VALUES ('a'),('a');
SELECT * FROM t1;
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (c CHAR(10) NULL, i INT NOT NULL AUTO_INCREMENT,
UNIQUE (c,i));
INSERT INTO t1 (c) VALUES (NULL),(NULL);
SELECT * FROM t1;
INSERT INTO t1 (c) VALUES ('a'),('a');
SELECT * FROM t1;
drop table t1;
#
# longer keys
#
create table t1 (i int, a char(200), b text, unique (a), unique (b(300))) charset utf8;
insert t1 values (1, repeat('a',210), repeat('b', 310));
insert t1 values (2, repeat(0xD0B1,215), repeat(0xD0B1, 310));
select i, length(a), length(b), char_length(a), char_length(b) from t1;
select i from t1 where a=repeat(_utf8 'a',200);
select i from t1 where a=repeat(_utf8 0xD0B1,200);
select i from t1 where b=repeat(_utf8 'b',310);
drop table t1;
#
# Test of key read with primary key (Bug #3497)
#
CREATE TABLE t1 (id int unsigned auto_increment, name char(50), primary key (id)) engine=myisam;
insert into t1 (name) values ('a'), ('b'),('c'),('d'),('e'),('f'),('g');
explain select 1 from t1 where id =2;
explain select 1 from t1 where id =2 or id=3;
explain select name from t1 where id =2;
ALTER TABLE t1 DROP PRIMARY KEY, ADD INDEX (id);
explain select 1 from t1 where id =2;
drop table t1;
#
# Test of problem with key read (Bug #3666)
#
CREATE TABLE t1 (numeropost mediumint(8) unsigned NOT NULL default '0', numreponse int(10) unsigned NOT NULL auto_increment, PRIMARY KEY (numeropost,numreponse), UNIQUE KEY numreponse (numreponse));
INSERT INTO t1 (numeropost,numreponse) VALUES ('1','1'),('1','2'),('2','3'),('2','4');
SELECT numeropost FROM t1 WHERE numreponse='1';
EXPLAIN SELECT numeropost FROM t1 WHERE numreponse='1';
FLUSH TABLES;
SELECT numeropost FROM t1 WHERE numreponse='1';
drop table t1;
#
# UNIQUE prefix keys and multi-byte charsets
#
create table t1 (c varchar(30) character set utf8, t text character set utf8, unique (c(2)), unique (t(3))) engine=myisam;
show create table t1;
insert t1 values ('cccc', 'tttt'),
(0xD0B1212223D0B1D0B1D0B1D0B1D0B1, 0xD0B1D0B1212223D0B1D0B1D0B1D0B1),
(0xD0B1222123D0B1D0B1D0B1D0B1D0B1, 0xD0B1D0B1222123D0B1D0B1D0B1D0B1);
--error ER_DUP_ENTRY
insert t1 (c) values ('cc22');
--error ER_DUP_ENTRY
insert t1 (t) values ('ttt22');
--error ER_DUP_ENTRY
insert t1 (c) values (0xD0B1212322D0B1D0B1D0B1D0B1D0B1);
--error ER_DUP_ENTRY
insert t1 (t) values (0xD0B1D0B1212322D0B1D0B1D0B1D0B1);
select c from t1 where c='cccc';
select t from t1 where t='tttt';
select c from t1 where c=0xD0B1212223D0B1D0B1D0B1D0B1D0B1;
select t from t1 where t=0xD0B1D0B1212223D0B1D0B1D0B1D0B1;
drop table t1;
#
# BUG#6151 - myisam index corruption
#
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (
c1 int,
c2 varbinary(240),
UNIQUE KEY (c1),
KEY (c2)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1,'\Z\Z\Z\Z');
INSERT INTO t1 VALUES (2,'\Z\Z\Z\Z\Z\Z');
INSERT INTO t1 VALUES (3,'\Z\Z\Z\Z');
select c1 from t1 where c2='\Z\Z\Z\Z';
DELETE FROM t1 WHERE (c1 = 1);
check table t1;
select c1 from t1 where c2='\Z\Z\Z\Z';
DELETE FROM t1 WHERE (c1 = 3);
check table t1;
select c1 from t1 where c2='\Z\Z\Z\Z';
#
# test delete of keys in a different order
#
truncate table t1;
insert into t1 values(1,"aaaa"),(2,"aaab"),(3,"aaac"),(4,"aaccc");
delete from t1 where c1=3;
delete from t1 where c1=1;
delete from t1 where c1=4;
check table t1;
drop table t1;
#
# Bug 6166: index prefix length of 0 not rejected
#
# this test should fail in 5.0
# to fix it, remove #ifdef in
# file sql_yacc.yy(key_part)
# create dedicated error code for this and
# and change my_printf_error() to my_error
--error 1391
create table t1 (c char(10), index (c(0)));
#
# Bug #6126: Duplicate columns in keys should fail
# Bug #6252: (dup)
#
--error 1060
create table t1 (c char(10), index (c,c));
--error 1060
create table t1 (c1 char(10), c2 char(10), index (c1,c2,c1));
--error 1060
create table t1 (c1 char(10), c2 char(10), index (c1,c1,c2));
--error 1060
create table t1 (c1 char(10), c2 char(10), index (c2,c1,c1));
create table t1 (c1 char(10), c2 char(10));
--error 1060
alter table t1 add key (c1,c1);
--error 1060
alter table t1 add key (c2,c1,c1);
--error 1060
alter table t1 add key (c1,c2,c1);
--error 1060
alter table t1 add key (c1,c1,c2);
drop table t1;
#
# Bug#11228: DESC shows arbitrary column as "PRI"
#
create table t1 (
i1 INT NOT NULL,
i2 INT NOT NULL,
UNIQUE i1idx (i1),
UNIQUE i2idx (i2));
desc t1;
show create table t1;
drop table t1;
#
# Bug#12565 - ERROR 1034 when running simple UPDATE or DELETE
# on large MyISAM table
#
create table t1 (
c1 int,
c2 varchar(20) not null,
primary key (c1),
key (c2(10))
) engine=myisam;
insert into t1 values (1,'');
insert into t1 values (2,' \t\tTest String');
insert into t1 values (3,' \n\tTest String');
update t1 set c2 = 'New Test String' where c1 = 1;
select * from t1;
drop table t1;
#
# If we use a partial field for a key that is actually the length of the
# field, and we extend the field, we end up with a key that includes the
# whole new length of the field.
#
create table t1 (a varchar(10), b varchar(10), key(a(10),b(10)));
show create table t1;
alter table t1 modify b varchar(20);
show create table t1;
alter table t1 modify a varchar(20);
show create table t1;
drop table t1;
#
# Bug #11227: Incorrectly reporting 'MUL' vs. 'UNI' on varchar
#
create table t1 (a int not null primary key, b varchar(20) not null unique);
desc t1;
drop table t1;
create table t1 (a int not null primary key, b int not null unique);
desc t1;
drop table t1;
create table t1 (a int not null primary key, b varchar(20) not null, unique (b(10)));
desc t1;
drop table t1;
create table t1 (a int not null primary key, b varchar(20) not null, c varchar(20) not null, unique(b(10),c(10)));
desc t1;
drop table t1;
# End of 4.1 tests
#
# WL#1563 - Modify MySQL to support on-line CREATE/DROP INDEX
# To test if this really works, you need to run with --debug
# and check the trace file.
#
# Create a table with named and unnamed indexes.
create table t1 (
c1 int,
c2 char(12),
c3 varchar(123),
c4 timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
index (c1),
index i1 (c1),
index i2 (c2),
index i3 (c3),
unique i4 (c4),
index i5 (c1, c2, c3, c4),
primary key (c2, c3),
index (c2, c4));
show create table t1;
# Some simple tests.
alter table t1 drop index c1;
alter table t1 add index (c1);
# This creates index 'c1_2'.
alter table t1 add index (c1);
alter table t1 drop index i3;
alter table t1 add index i3 (c3);
# Two indexes at the same time.
alter table t1 drop index i2, drop index i4;
alter table t1 add index i2 (c2), add index i4 (c4);
# Three indexes, one of them reversely.
alter table t1 drop index i2, drop index i4, add index i6 (c2, c4);
alter table t1 add index i2 (c2), add index i4 (c4), drop index i6;
# include an unique index.
alter table t1 drop index i2, drop index i4, add unique i4 (c4);
alter table t1 add index i2 (c2), drop index i4, add index i4 (c4);
# Modify an index by changing its definition.
alter table t1 drop index c2, add index (c2(4),c3(7));
# Change nothing. The new key definition is the same as the old one.
alter table t1 drop index c2, add index (c2(4),c3(7));
# Test primary key handling.
alter table t1 add primary key (c1, c2), drop primary key;
alter table t1 drop primary key;
# Drop is checked first. Primary key must exist.
--error 1091
alter table t1 add primary key (c1, c2), drop primary key;
show create table t1;
# Insert non-unique values.
insert into t1 values(1, 'a', 'a', NULL);
insert into t1 values(1, 'b', 'b', NULL);
# Drop some indexes for new adds.
alter table t1 drop index i3, drop index i2, drop index i1;
# Add indexes, one is unique on non-unique values.
--error ER_DUP_ENTRY
alter table t1 add index i3 (c3), add index i2 (c2), add unique index i1 (c1);
drop table t1;
#
# Bug #20604: Test for disabled keys with aggregate functions and FORCE INDEX.
#
CREATE TABLE t1( a TINYINT, KEY(a) ) ENGINE=MyISAM;
INSERT INTO t1 VALUES( 1 );
ALTER TABLE t1 DISABLE KEYS;
EXPLAIN SELECT MAX(a) FROM t1 FORCE INDEX(a);
drop table t1;
#
# Bug #24778: Innodb: No result when using ORDER BY
#
CREATE TABLE t1 (
a INTEGER auto_increment PRIMARY KEY,
b INTEGER NOT NULL,
c INTEGER NOT NULL,
d CHAR(64)
);
CREATE TABLE t2 (
a INTEGER auto_increment PRIMARY KEY,
b INTEGER NOT NULL,
c SMALLINT NOT NULL,
d DATETIME NOT NULL,
e SMALLINT NOT NULL,
f INTEGER NOT NULL,
g INTEGER NOT NULL,
h SMALLINT NOT NULL,
i INTEGER NOT NULL,
j INTEGER NOT NULL,
UNIQUE INDEX (b),
INDEX (b, d, e, f, g, h, i, j, c),
INDEX (c)
);
INSERT INTO t2 VALUES
(NULL, 1, 254, '1000-01-01 00:00:00', 257, 0, 0, 0, 0, 0),
(NULL, 2, 1, '2004-11-30 12:00:00', 1, 0, 0, 0, 0, 0),
(NULL, 3, 1, '2004-11-30 12:00:00', 1, 0, 0, 2, -21600, 0),
(NULL, 4, 1, '2004-11-30 12:00:00', 1, 0, 0, 2, -10800, 0),
(NULL, 5, 1, '2004-11-30 12:00:00', 1, 0, 0, 5, -10800, 0),
(NULL, 6, 1, '2004-11-30 12:00:00', 102, 0, 0, 0, 0, 0),
(NULL, 7, 1, '2004-11-30 12:00:00', 105, 2, 0, 0, 0, 0),
(NULL, 8, 1, '2004-11-30 12:00:00', 105, 10, 0, 0, 0, 0);
INSERT INTO t1 (b, c, d) VALUES
(3388000, -553000, NULL),
(3388000, -553000, NULL);
# psergey/sergefp: This crashes for a mysterious reason with MRR + Semijoin
# opts. TODO: fix it.
#SELECT *
#FROM t2 c JOIN t1 pa ON c.b = pa.a
#WHERE c.c = 1
#ORDER BY c.b, c.d
#;
DROP TABLE t1, t2;
#
# Bug #31137: Assertion failed: primary_key_no == -1 || primary_key_no == 0
#
create table t1(a int not null, key aa(a),
b char(10) not null, unique key bb(b(1)),
c char(4) not null, unique key cc(c));
desc t1;
show create table t1;
drop table t1;
create table t1(a int not null, key aa(a),
b char(10) not null, unique key bb(b(1)),
c char(4) not null);
desc t1;
alter table t1 add unique key cc(c);
desc t1;
show create table t1;
drop table t1;
--echo End of 5.0 tests
#
# Bug #31148: bool close_thread_table(THD*, TABLE**): Assertion
# `table->key_read == 0' failed.
#
--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings
CREATE TABLE t1 (a INT PRIMARY KEY AUTO_INCREMENT);
INSERT INTO t1 VALUES (), (), ();
SELECT 1 AS c1
FROM t1
ORDER BY (
SELECT 1 AS c2
FROM t1
GROUP BY GREATEST(LAST_INSERT_ID(), t1.a) ASC
LIMIT 1);
DROP TABLE t1;
#
# Bug #31974: Wrong EXPLAIN output
#
CREATE TABLE t1 (a INT, b INT, INDEX (a,b));
INSERT INTO t1 (a, b)
VALUES
(1,1), (1,2), (1,3), (1,4), (1,5),
(2,2), (2,3), (2,1), (3,1), (4,1), (4,2), (4,3), (4,4), (4,5), (4,6);
EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE
(SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
SELECT 1 as RES FROM t1 AS t1_outer WHERE
(SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
DROP TABLE t1;
--echo #
--echo # Bug#18144: Cost with FORCE/USE index seems incorrect in some cases.
--echo #
--echo # We are interested in showing that the cost for the last plan is higher
--echo # than for the preceding two plans.
--echo #
CREATE TABLE t1( a INT, b INT, KEY( a ) );
INSERT INTO t1 values (1, 2), (1, 3), (2, 3), (2, 4), (3, 4), (3, 5);
EXPLAIN SELECT a, SUM( b ) FROM t1 GROUP BY a;
SHOW STATUS LIKE 'Last_query_cost';
EXPLAIN SELECT a, SUM( b ) FROM t1 USE INDEX( a ) GROUP BY a;
SHOW STATUS LIKE 'Last_query_cost';
EXPLAIN SELECT a, SUM( b ) FROM t1 FORCE INDEX( a ) GROUP BY a;
SHOW STATUS LIKE 'Last_query_cost';
DROP TABLE t1;
|