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
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
|
/*
Copyright (c) 2016 MariaDB Corporation
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
All methods pertaining to temporary tables.
*/
#include "mariadb.h"
#include "sql_acl.h" /* TMP_TABLE_ACLS */
#include "sql_base.h" /* tdc_create_key */
#include "lock.h" /* mysql_lock_remove */
#include "log_event.h" /* Query_log_event */
#include "sql_show.h" /* append_identifier */
#include "sql_handler.h" /* mysql_ha_rm_temporary_tables */
#include "rpl_rli.h" /* rpl_group_info */
#define IS_USER_TABLE(A) ((A->tmp_table == TRANSACTIONAL_TMP_TABLE) || \
(A->tmp_table == NON_TRANSACTIONAL_TMP_TABLE))
/**
Check whether temporary tables exist. The decision is made based on the
existence of TMP_TABLE_SHAREs in Open_tables_state::temporary_tables list.
@return false Temporary tables exist
true No temporary table exist
*/
bool THD::has_thd_temporary_tables()
{
DBUG_ENTER("THD::has_thd_temporary_tables");
bool result= (temporary_tables && !temporary_tables->is_empty());
DBUG_RETURN(result);
}
/**
Create a temporary table, open it and return the TABLE handle.
@param hton [IN] Handlerton
@param frm [IN] Binary frm image
@param path [IN] File path (without extension)
@param db [IN] Schema name
@param table_name [IN] Table name
@param open_in_engine [IN] Whether open table in SE
@return Success A pointer to table object
Failure NULL
*/
TABLE *THD::create_and_open_tmp_table(handlerton *hton,
LEX_CUSTRING *frm,
const char *path,
const char *db,
const char *table_name,
bool open_in_engine,
bool open_internal_tables)
{
DBUG_ENTER("THD::create_and_open_tmp_table");
TMP_TABLE_SHARE *share;
TABLE *table= NULL;
if ((share= create_temporary_table(hton, frm, path, db, table_name)))
{
open_options|= HA_OPEN_FOR_CREATE;
table= open_temporary_table(share, table_name, open_in_engine);
open_options&= ~HA_OPEN_FOR_CREATE;
/*
Failed to open a temporary table instance. As we are not passing
the created TMP_TABLE_SHARE to the caller, we must remove it from
the list and free it here.
*/
if (!table)
{
/* Remove the TABLE_SHARE from the list of temporary tables. */
temporary_tables->remove(share);
/* Free the TMP_TABLE_SHARE. */
free_tmp_table_share(share, false);
DBUG_RETURN(0);
}
/* Open any related tables */
if (open_internal_tables && table->internal_tables &&
open_and_lock_internal_tables(table, open_in_engine))
{
drop_temporary_table(table, NULL, false);
DBUG_RETURN(0);
}
}
DBUG_RETURN(table);
}
/**
Check whether an open table with db/table name is in use.
@param db [IN] Database name
@param table_name [IN] Table name
@return Success Pointer to first used table instance.
Failure NULL
*/
TABLE *THD::find_temporary_table(const char *db,
const char *table_name)
{
DBUG_ENTER("THD::find_temporary_table");
TABLE *table;
char key[MAX_DBKEY_LENGTH];
uint key_length;
bool locked;
if (!has_temporary_tables())
{
DBUG_RETURN(NULL);
}
key_length= create_tmp_table_def_key(key, db, table_name);
locked= lock_temporary_tables();
table = find_temporary_table(key, key_length, TMP_TABLE_IN_USE);
if (locked)
{
DBUG_ASSERT(m_tmp_tables_locked);
unlock_temporary_tables();
}
DBUG_RETURN(table);
}
/**
Check whether an open table specified in TABLE_LIST is in use.
@return tl [IN] TABLE_LIST
@return Success Pointer to first used table instance.
Failure NULL
*/
TABLE *THD::find_temporary_table(const TABLE_LIST *tl)
{
DBUG_ENTER("THD::find_temporary_table");
if (!has_temporary_tables())
{
DBUG_RETURN(NULL);
}
TABLE *table= find_temporary_table(tl->get_db_name(), tl->get_table_name());
DBUG_RETURN(table);
}
/**
Check whether a temporary table exists with the specified key.
The key, in this case, is not the usual key used for temporary tables.
It does not contain server_id & pseudo_thread_id. This function is
essentially used use to check whether there is any temporary table
which _shadows_ a base table.
(see: Query_cache::send_result_to_client())
@return Success A pointer to table share object
Failure NULL
*/
TMP_TABLE_SHARE *THD::find_tmp_table_share_w_base_key(const char *key,
uint key_length)
{
DBUG_ENTER("THD::find_tmp_table_share_w_base_key");
TMP_TABLE_SHARE *share;
TMP_TABLE_SHARE *result= NULL;
bool locked;
if (!has_temporary_tables())
{
DBUG_RETURN(NULL);
}
locked= lock_temporary_tables();
All_tmp_tables_list::Iterator it(*temporary_tables);
while ((share= it++))
{
if ((share->table_cache_key.length - TMP_TABLE_KEY_EXTRA) == key_length
&& !memcmp(share->table_cache_key.str, key, key_length))
{
result= share;
}
}
if (locked)
{
DBUG_ASSERT(m_tmp_tables_locked);
unlock_temporary_tables();
}
DBUG_RETURN(result);
}
/**
Lookup the TMP_TABLE_SHARE using the given db/table_name.The server_id and
pseudo_thread_id used to generate table definition key is taken from THD
(see create_tmp_table_def_key()). Return NULL is none found.
@return Success A pointer to table share object
Failure NULL
*/
TMP_TABLE_SHARE *THD::find_tmp_table_share(const char *db,
const char *table_name)
{
DBUG_ENTER("THD::find_tmp_table_share");
TMP_TABLE_SHARE *share;
char key[MAX_DBKEY_LENGTH];
uint key_length;
key_length= create_tmp_table_def_key(key, db, table_name);
share= find_tmp_table_share(key, key_length);
DBUG_RETURN(share);
}
/**
Lookup TMP_TABLE_SHARE using the specified TABLE_LIST element.
Return NULL is none found.
@param tl [IN] Table
@return Success A pointer to table share object
Failure NULL
*/
TMP_TABLE_SHARE *THD::find_tmp_table_share(const TABLE_LIST *tl)
{
DBUG_ENTER("THD::find_tmp_table_share");
TMP_TABLE_SHARE *share= find_tmp_table_share(tl->get_db_name(),
tl->get_table_name());
DBUG_RETURN(share);
}
/**
Lookup TMP_TABLE_SHARE using the specified table definition key.
Return NULL is none found.
@return Success A pointer to table share object
Failure NULL
*/
TMP_TABLE_SHARE *THD::find_tmp_table_share(const char *key, uint key_length)
{
DBUG_ENTER("THD::find_tmp_table_share");
TMP_TABLE_SHARE *share;
TMP_TABLE_SHARE *result= NULL;
bool locked;
if (!has_temporary_tables())
{
DBUG_RETURN(NULL);
}
locked= lock_temporary_tables();
All_tmp_tables_list::Iterator it(*temporary_tables);
while ((share= it++))
{
if (share->table_cache_key.length == key_length &&
!(memcmp(share->table_cache_key.str, key, key_length)))
{
result= share;
break;
}
}
if (locked)
{
DBUG_ASSERT(m_tmp_tables_locked);
unlock_temporary_tables();
}
DBUG_RETURN(result);
}
/**
Find a temporary table specified by TABLE_LIST instance in the open table
list and prepare its TABLE instance for use. If
This function tries to resolve this table in the list of temporary tables
of this thread. Temporary tables are thread-local and "shadow" base
tables with the same name.
@note In most cases one should use THD::open_tables() instead
of this call.
@note One should finalize process of opening temporary table for table
list element by calling open_and_process_table(). This function
is responsible for table version checking and handling of merge
tables.
@note We used to check global_read_lock before opening temporary tables.
However, that limitation was artificial and is removed now.
@param tl [IN] TABLE_LIST
@return Error status.
@retval false On success. If a temporary table exists
for the given key, tl->table is set.
@retval true On error. my_error() has been called.
*/
bool THD::open_temporary_table(TABLE_LIST *tl)
{
DBUG_ENTER("THD::open_temporary_table");
DBUG_PRINT("enter", ("table: '%s'.'%s'", tl->db.str, tl->table_name.str));
TMP_TABLE_SHARE *share;
TABLE *table= NULL;
/*
Code in open_table() assumes that TABLE_LIST::table can be non-zero only
for pre-opened temporary tables.
*/
DBUG_ASSERT(tl->table == NULL);
/*
This function should not be called for cases when derived or I_S
tables can be met since table list elements for such tables can
have invalid db or table name.
Instead THD::open_tables() should be used.
*/
DBUG_ASSERT(!tl->derived && !tl->schema_table);
if (tl->open_type == OT_BASE_ONLY || !has_temporary_tables())
{
DBUG_PRINT("info", ("skip_temporary is set or no temporary tables"));
DBUG_RETURN(false);
}
/*
Temporary tables are not safe for parallel replication. They were
designed to be visible to one thread only, so have no table locking.
Thus there is no protection against two conflicting transactions
committing in parallel and things like that.
So for now, anything that uses temporary tables will be serialised
with anything before it, when using parallel replication.
*/
if (rgi_slave &&
rgi_slave->is_parallel_exec &&
find_temporary_table(tl) &&
wait_for_prior_commit())
DBUG_RETURN(true);
/*
First check if there is a reusable open table available in the
open table list.
*/
if (find_and_use_tmp_table(tl, &table))
{
DBUG_RETURN(true); /* Error */
}
/*
No reusable table was found. We will have to open a new instance.
*/
if (!table && (share= find_tmp_table_share(tl)))
{
table= open_temporary_table(share, tl->get_table_name(), true);
}
if (!table)
{
if (tl->open_type == OT_TEMPORARY_ONLY &&
tl->open_strategy == TABLE_LIST::OPEN_NORMAL)
{
my_error(ER_NO_SUCH_TABLE, MYF(0), tl->db.str, tl->table_name.str);
DBUG_RETURN(true);
}
DBUG_RETURN(false);
}
#ifdef WITH_PARTITION_STORAGE_ENGINE
if (tl->partition_names)
{
/* Partitioned temporary tables is not supported. */
DBUG_ASSERT(!table->part_info);
my_error(ER_PARTITION_CLAUSE_ON_NONPARTITIONED, MYF(0));
DBUG_RETURN(true);
}
#endif
table->query_id= query_id;
thread_specific_used= true;
/* It is neither a derived table nor non-updatable view. */
tl->updatable= true;
tl->table= table;
table->init(this, tl);
DBUG_PRINT("info", ("Using temporary table"));
DBUG_RETURN(false);
}
/**
Pre-open temporary tables corresponding to table list elements.
@note One should finalize process of opening temporary tables
by calling open_tables(). This function is responsible
for table version checking and handling of merge tables.
@param tl [IN] TABLE_LIST
@return false On success. If a temporary table exists
for the given element, tl->table is set.
true On error. my_error() has been called.
*/
bool THD::open_temporary_tables(TABLE_LIST *tl)
{
DBUG_ENTER("THD::open_temporary_tables");
TABLE_LIST *first_not_own= lex->first_not_own_table();
for (TABLE_LIST *table= tl; table && table != first_not_own;
table= table->next_global)
{
if (table->derived || table->schema_table)
{
/*
Derived and I_S tables will be handled by a later call to open_tables().
*/
continue;
}
if (open_temporary_table(table))
{
DBUG_RETURN(true);
}
}
DBUG_RETURN(false);
}
/**
Close all temporary tables created by 'CREATE TEMPORARY TABLE' for thread
creates one DROP TEMPORARY TABLE binlog event for each pseudo-thread.
Temporary tables created in a sql slave is closed by
Relay_log_info::close_temporary_tables().
@return false Success
true Failure
*/
bool THD::close_temporary_tables()
{
DBUG_ENTER("THD::close_temporary_tables");
TMP_TABLE_SHARE *share;
TABLE *table;
bool error= false;
if (!has_thd_temporary_tables())
{
if (temporary_tables)
{
my_free(temporary_tables);
temporary_tables= NULL;
}
DBUG_RETURN(false);
}
DBUG_ASSERT(!rgi_slave);
/*
Ensure we don't have open HANDLERs for tables we are about to close.
This is necessary when THD::close_temporary_tables() is called as
part of execution of BINLOG statement (e.g. for format description event).
*/
mysql_ha_rm_temporary_tables(this);
/* Close all open temporary tables. */
All_tmp_tables_list::Iterator it(*temporary_tables);
while ((share= it++))
{
/* Traverse the table list. */
while ((table= share->all_tmp_tables.pop_front()))
{
free_temporary_table(table);
}
}
// Write DROP TEMPORARY TABLE query log events to binary log.
if (mysql_bin_log.is_open())
{
error= log_events_and_free_tmp_shares();
}
else
{
while ((share= temporary_tables->pop_front()))
{
free_tmp_table_share(share, true);
}
}
/* By now, there mustn't be any elements left in the list. */
DBUG_ASSERT(temporary_tables->is_empty());
my_free(temporary_tables);
temporary_tables= NULL;
DBUG_RETURN(error);
}
/**
Rename a temporary table.
@param table [IN] Table handle
@param db [IN] New schema name
@param table_name [IN] New table name
@return false Success
true Error
*/
bool THD::rename_temporary_table(TABLE *table,
const LEX_CSTRING *db,
const LEX_CSTRING *table_name)
{
char *key;
uint key_length;
TABLE_SHARE *share= table->s;
DBUG_ENTER("THD::rename_temporary_table");
if (!(key= (char *) alloc_root(&share->mem_root, MAX_DBKEY_LENGTH)))
DBUG_RETURN(true);
/*
Temporary tables are renamed by simply changing their table definition key.
*/
key_length= create_tmp_table_def_key(key, db->str, table_name->str);
share->set_table_cache_key(key, key_length);
DBUG_RETURN(false);
}
/**
Drop a temporary table.
Try to locate the table in the list of open temporary tables.
If the table is found:
- If the table is locked with LOCK TABLES or by prelocking,
unlock it and remove it from the list of locked tables
(THD::lock). Currently only transactional temporary tables
are locked.
- Close the temporary table, remove its .FRM.
- Remove the table share from the list of temporary table shares.
This function is used to drop user temporary tables, as well as
internal tables created in CREATE TEMPORARY TABLE ... SELECT
or ALTER TABLE.
@param table [IN] Temporary table to be deleted
@param is_trans [OUT] Is set to the type of the table:
transactional (e.g. innodb) as true or
non-transactional (e.g. myisam) as false.
@paral delete_table [IN] Whether to delete the table files?
@return false Table was dropped
true Error
*/
bool THD::drop_temporary_table(TABLE *table,
bool *is_trans,
bool delete_table)
{
DBUG_ENTER("THD::drop_temporary_table");
TMP_TABLE_SHARE *share;
TABLE *tab;
bool result= false;
bool locked;
DBUG_ASSERT(table);
DBUG_PRINT("tmptable", ("Dropping table: '%s'.'%s'",
table->s->db.str, table->s->table_name.str));
locked= lock_temporary_tables();
share= tmp_table_share(table);
/* Table might be in use by some outer statement. */
All_share_tables_list::Iterator it(share->all_tmp_tables);
while ((tab= it++))
{
if (tab != table && tab->query_id != 0)
{
/* Found a table instance in use. This table cannot be be dropped. */
my_error(ER_CANT_REOPEN_TABLE, MYF(0), table->alias.c_ptr());
result= true;
goto end;
}
}
if (is_trans)
*is_trans= table->file->has_transactions();
/*
Iterate over the list of open tables and close them.
*/
while ((tab= share->all_tmp_tables.pop_front()))
{
/*
We need to set the THD as it may be different in case of
parallel replication
*/
tab->in_use= this;
free_temporary_table(tab);
}
DBUG_ASSERT(temporary_tables);
/* Remove the TABLE_SHARE from the list of temporary tables. */
temporary_tables->remove(share);
/* Free the TABLE_SHARE and/or delete the files. */
free_tmp_table_share(share, delete_table);
end:
if (locked)
{
DBUG_ASSERT(m_tmp_tables_locked);
unlock_temporary_tables();
}
DBUG_RETURN(result);
}
/**
Delete the temporary table files.
@param base [IN] Handlerton for table to be deleted.
@param path [IN] Path to the table to be deleted (i.e. path
to its .frm without an extension).
@return false Success
true Error
*/
bool THD::rm_temporary_table(handlerton *base, const char *path)
{
DBUG_ENTER("THD::rm_temporary_table");
bool error= false;
handler *file;
char frm_path[FN_REFLEN + 1];
strxnmov(frm_path, sizeof(frm_path) - 1, path, reg_ext, NullS);
if (mysql_file_delete(key_file_frm, frm_path, MYF(0)))
{
error= true;
}
file= get_new_handler((TABLE_SHARE*) 0, current_thd->mem_root, base);
if (file && file->ha_delete_table(path))
{
error= true;
sql_print_warning("Could not remove temporary table: '%s', error: %d",
path, my_errno);
}
delete file;
DBUG_RETURN(error);
}
/**
Mark all temporary tables which were used by the current statement or
sub-statement as free for reuse, but only if the query_id can be cleared.
@remark For temp tables associated with a open SQL HANDLER the query_id
is not reset until the HANDLER is closed.
*/
void THD::mark_tmp_tables_as_free_for_reuse()
{
DBUG_ENTER("THD::mark_tmp_tables_as_free_for_reuse");
TMP_TABLE_SHARE *share;
TABLE *table;
bool locked;
if (query_id == 0)
{
/*
Thread has not executed any statement and has not used any
temporary tables.
*/
DBUG_VOID_RETURN;
}
if (!has_temporary_tables())
{
DBUG_VOID_RETURN;
}
locked= lock_temporary_tables();
All_tmp_tables_list::Iterator it(*temporary_tables);
while ((share= it++))
{
All_share_tables_list::Iterator tables_it(share->all_tmp_tables);
while ((table= tables_it++))
{
if ((table->query_id == query_id) && !table->open_by_handler)
{
mark_tmp_table_as_free_for_reuse(table);
}
}
}
if (locked)
{
DBUG_ASSERT(m_tmp_tables_locked);
unlock_temporary_tables();
}
if (rgi_slave)
{
/*
Temporary tables are shared with other by sql execution threads.
As a safety measure, clear the pointer to the common area.
*/
temporary_tables= NULL;
}
DBUG_VOID_RETURN;
}
/**
Reset a single temporary table. Effectively this "closes" one temporary
table in a session.
@param table Temporary table
@return void
*/
void THD::mark_tmp_table_as_free_for_reuse(TABLE *table)
{
DBUG_ENTER("THD::mark_tmp_table_as_free_for_reuse");
DBUG_ASSERT(table->s->tmp_table);
table->query_id= 0;
table->file->ha_reset();
/* Detach temporary MERGE children from temporary parent. */
DBUG_ASSERT(table->file);
table->file->extra(HA_EXTRA_DETACH_CHILDREN);
/*
Reset temporary table lock type to it's default value (TL_WRITE).
Statements such as INSERT INTO .. SELECT FROM tmp, CREATE TABLE
.. SELECT FROM tmp and UPDATE may under some circumstances modify
the lock type of the tables participating in the statement. This
isn't a problem for non-temporary tables since their lock type is
reset at every open, but the same does not occur for temporary
tables for historical reasons.
Furthermore, the lock type of temporary tables is not really that
important because they can only be used by one query at a time.
Nonetheless, it's safer from a maintenance point of view to reset
the lock type of this singleton TABLE object as to not cause problems
when the table is reused.
Even under LOCK TABLES mode its okay to reset the lock type as
LOCK TABLES is allowed (but ignored) for a temporary table.
*/
table->reginfo.lock_type= TL_WRITE;
DBUG_VOID_RETURN;
}
/**
Remove and return the specified table's TABLE_SHARE from the temporary
tables list.
@param table [IN] Table
@return TMP_TABLE_SHARE of the specified table.
*/
TMP_TABLE_SHARE *THD::save_tmp_table_share(TABLE *table)
{
DBUG_ENTER("THD::save_tmp_table_share");
TMP_TABLE_SHARE *share;
lock_temporary_tables();
DBUG_ASSERT(temporary_tables);
share= tmp_table_share(table);
temporary_tables->remove(share);
unlock_temporary_tables();
DBUG_RETURN(share);
}
/**
Add the specified TMP_TABLE_SHARE to the temporary tables list.
@param share [IN] Table share
@return void
*/
void THD::restore_tmp_table_share(TMP_TABLE_SHARE *share)
{
DBUG_ENTER("THD::restore_tmp_table_share");
lock_temporary_tables();
DBUG_ASSERT(temporary_tables);
temporary_tables->push_front(share);
unlock_temporary_tables();
DBUG_VOID_RETURN;
}
/**
If its a replication slave, report whether slave temporary tables
exist (Relay_log_info::save_temporary_tables) or report about THD
temporary table (Open_tables_state::temporary_tables) otherwise.
@return false Temporary tables exist
true No temporary table exist
*/
inline bool THD::has_temporary_tables()
{
DBUG_ENTER("THD::has_temporary_tables");
bool result= (rgi_slave
? (rgi_slave->rli->save_temporary_tables &&
!rgi_slave->rli->save_temporary_tables->is_empty())
: (has_thd_temporary_tables()));
DBUG_RETURN(result);
}
/**
Create a table definition key.
@param key [OUT] Buffer for the key to be created (must
be of size MAX_DBKRY_LENGTH)
@param db [IN] Database name
@param table_name [IN] Table name
@return Key length.
@note
The table key is create from:
db + \0
table_name + \0
Additionally, we add the following to make each temporary table unique on
the slave.
4 bytes of master thread id
4 bytes of pseudo thread id
*/
uint THD::create_tmp_table_def_key(char *key, const char *db,
const char *table_name)
{
DBUG_ENTER("THD::create_tmp_table_def_key");
uint key_length;
key_length= tdc_create_key(key, db, table_name);
int4store(key + key_length, variables.server_id);
int4store(key + key_length + 4, variables.pseudo_thread_id);
key_length += TMP_TABLE_KEY_EXTRA;
DBUG_RETURN(key_length);
}
/**
Create a temporary table.
@param hton [IN] Handlerton
@param frm [IN] Binary frm image
@param path [IN] File path (without extension)
@param db [IN] Schema name
@param table_name [IN] Table name
@return Success A pointer to table share object
Failure NULL
*/
TMP_TABLE_SHARE *THD::create_temporary_table(handlerton *hton,
LEX_CUSTRING *frm,
const char *path,
const char *db,
const char *table_name)
{
DBUG_ENTER("THD::create_temporary_table");
TMP_TABLE_SHARE *share;
char key_cache[MAX_DBKEY_LENGTH];
char *saved_key_cache;
char *tmp_path;
uint key_length;
bool locked;
int res;
/* Temporary tables are not safe for parallel replication. */
if (rgi_slave &&
rgi_slave->is_parallel_exec &&
wait_for_prior_commit())
DBUG_RETURN(NULL);
/* Create the table definition key for the temporary table. */
key_length= create_tmp_table_def_key(key_cache, db, table_name);
if (!(share= (TMP_TABLE_SHARE *) my_malloc(sizeof(TMP_TABLE_SHARE) +
strlen(path) + 1 + key_length,
MYF(MY_WME))))
{
DBUG_RETURN(NULL); /* Out of memory */
}
tmp_path= (char *)(share + 1);
saved_key_cache= strmov(tmp_path, path) + 1;
memcpy(saved_key_cache, key_cache, key_length);
init_tmp_table_share(this, share, saved_key_cache, key_length,
strend(saved_key_cache) + 1, tmp_path);
share->db_plugin= ha_lock_engine(this, hton);
/*
Prefer using frm image over file. The image might not be available in
ALTER TABLE, when the discovering engine took over the ownership (see
TABLE::read_frm_image).
*/
res= (frm->str)
? share->init_from_binary_frm_image(this, false, frm->str, frm->length)
: open_table_def(this, share, GTS_TABLE | GTS_USE_DISCOVERY);
if (res)
{
/*
No need to lock share->mutex as this is not needed for temporary tables.
*/
free_table_share(share);
my_free(share);
DBUG_RETURN(NULL);
}
share->m_psi= PSI_CALL_get_table_share(true, share);
locked= lock_temporary_tables();
/* Initialize the all_tmp_tables list. */
share->all_tmp_tables.empty();
/*
We need to alloc & initialize temporary_tables if this happens
to be the very first temporary table.
*/
if (!temporary_tables)
{
if ((temporary_tables=
(All_tmp_tables_list *) my_malloc(sizeof(All_tmp_tables_list),
MYF(MY_WME))))
{
temporary_tables->empty();
}
else
{
DBUG_RETURN(NULL); /* Out of memory */
}
}
/* Add share to the head of the temporary table share list. */
temporary_tables->push_front(share);
if (locked)
{
DBUG_ASSERT(m_tmp_tables_locked);
unlock_temporary_tables();
}
DBUG_RETURN(share);
}
/**
Find a table with the specified key.
@param key [IN] Key
@param key_length [IN] Key length
@param state [IN] Open table state to look for
@return Success Pointer to the table instance.
Failure NULL
*/
TABLE *THD::find_temporary_table(const char *key, uint key_length,
Temporary_table_state state)
{
DBUG_ENTER("THD::find_temporary_table");
TMP_TABLE_SHARE *share;
TABLE *table;
TABLE *result= NULL;
bool locked;
locked= lock_temporary_tables();
All_tmp_tables_list::Iterator it(*temporary_tables);
while ((share= it++))
{
if (share->table_cache_key.length == key_length &&
!(memcmp(share->table_cache_key.str, key, key_length)))
{
/* A matching TMP_TABLE_SHARE is found. */
All_share_tables_list::Iterator tables_it(share->all_tmp_tables);
while ((table= tables_it++))
{
switch (state)
{
case TMP_TABLE_IN_USE:
if (table->query_id > 0)
{
result= table;
goto done;
}
break;
case TMP_TABLE_NOT_IN_USE:
if (table->query_id == 0)
{
result= table;
goto done;
}
break;
case TMP_TABLE_ANY:
{
result= table;
goto done;
}
break;
default: /* Invalid */
DBUG_ASSERT(0);
goto done;
}
}
}
}
done:
if (locked)
{
DBUG_ASSERT(m_tmp_tables_locked);
unlock_temporary_tables();
}
DBUG_RETURN(result);
}
/**
Open a table from the specified TABLE_SHARE with the given alias.
@param share [IN] Table share
@param alias [IN] Table alias
@param open_in_engine [IN] Whether open table in SE
@return Success A pointer to table object
Failure NULL
*/
TABLE *THD::open_temporary_table(TMP_TABLE_SHARE *share,
const char *alias_arg,
bool open_in_engine)
{
TABLE *table;
LEX_CSTRING alias= {alias_arg, strlen(alias_arg) };
DBUG_ENTER("THD::open_temporary_table");
if (!(table= (TABLE *) my_malloc(sizeof(TABLE), MYF(MY_WME))))
{
DBUG_RETURN(NULL); /* Out of memory */
}
if (open_table_from_share(this, share, &alias,
open_in_engine ? (uint)HA_OPEN_KEYFILE : 0,
EXTRA_RECORD,
(ha_open_options |
(open_options & HA_OPEN_FOR_CREATE)),
table, open_in_engine ? false : true))
{
my_free(table);
DBUG_RETURN(NULL);
}
table->reginfo.lock_type= TL_WRITE; /* Simulate locked */
table->grant.privilege= TMP_TABLE_ACLS;
share->tmp_table= (table->file->has_transaction_manager() ?
TRANSACTIONAL_TMP_TABLE : NON_TRANSACTIONAL_TMP_TABLE);
share->not_usable_by_query_cache= 1;
table->pos_in_table_list= 0;
table->query_id= query_id;
/* Add table to the head of table list. */
share->all_tmp_tables.push_front(table);
/* Increment Slave_open_temp_table_definitions status variable count. */
if (rgi_slave)
{
thread_safe_increment32(&slave_open_temp_tables);
}
DBUG_PRINT("tmptable", ("Opened table: '%s'.'%s'%p", table->s->db.str,
table->s->table_name.str, table));
DBUG_RETURN(table);
}
/**
Find a reusable table in the open table list using the specified TABLE_LIST.
@param tl [IN] Table list
@param out_table [OUT] Pointer to the requested TABLE object
@return Success false
Failure true
*/
bool THD::find_and_use_tmp_table(const TABLE_LIST *tl,
TABLE **out_table)
{
DBUG_ENTER("THD::find_and_use_tmp_table");
char key[MAX_DBKEY_LENGTH];
uint key_length;
bool result;
key_length= create_tmp_table_def_key(key, tl->get_db_name(),
tl->get_table_name());
result=
use_temporary_table(find_temporary_table(key, key_length,
TMP_TABLE_NOT_IN_USE),
out_table);
DBUG_RETURN(result);
}
/**
Mark table as in-use.
@param table [IN] Table to be marked in-use
@param out_table [OUT] Pointer to the specified table
@return false Success
true Error
*/
bool THD::use_temporary_table(TABLE *table, TABLE **out_table)
{
DBUG_ENTER("THD::use_temporary_table");
*out_table= table;
/* The following can happen if find_temporary_table() returns NULL */
if (!table)
DBUG_RETURN(false);
/*
Temporary tables are not safe for parallel replication. They were
designed to be visible to one thread only, so have no table locking.
Thus there is no protection against two conflicting transactions
committing in parallel and things like that.
So for now, anything that uses temporary tables will be serialised
with anything before it, when using parallel replication.
TODO: We might be able to introduce a reference count or something
on temp tables, and have slave worker threads wait for it to reach
zero before being allowed to use the temp table. Might not be worth
it though, as statement-based replication using temporary tables is
in any case rather fragile.
*/
if (rgi_slave &&
rgi_slave->is_parallel_exec &&
wait_for_prior_commit())
DBUG_RETURN(true);
/*
We need to set the THD as it may be different in case of
parallel replication
*/
table->in_use= this;
DBUG_RETURN(false);
}
/**
Close a temporary table.
@param table [IN] Table handle
@return void
*/
void THD::close_temporary_table(TABLE *table)
{
DBUG_ENTER("THD::close_temporary_table");
DBUG_PRINT("tmptable", ("closing table: '%s'.'%s'%p alias: '%s'",
table->s->db.str, table->s->table_name.str,
table, table->alias.c_ptr()));
closefrm(table);
my_free(table);
if (rgi_slave)
{
/* Natural invariant of temporary_tables */
DBUG_ASSERT(slave_open_temp_tables || !temporary_tables);
/* Decrement Slave_open_temp_table_definitions status variable count. */
thread_safe_decrement32(&slave_open_temp_tables);
}
DBUG_VOID_RETURN;
}
/**
Write query log events with "DROP TEMPORARY TABLES .." for each pseudo
thread to the binary log.
@return false Success
true Error
*/
bool THD::log_events_and_free_tmp_shares()
{
DBUG_ENTER("THD::log_events_and_free_tmp_shares");
DBUG_ASSERT(!rgi_slave);
TMP_TABLE_SHARE *share;
TMP_TABLE_SHARE *sorted;
TMP_TABLE_SHARE *prev_sorted;
// Assume thd->variables.option_bits has OPTION_QUOTE_SHOW_CREATE.
bool was_quote_show= true;
bool error= false;
bool found_user_tables= false;
// Better add "IF EXISTS" in case a RESET MASTER has been done.
const char stub[]= "DROP /*!40005 TEMPORARY */ TABLE IF EXISTS ";
char buf[FN_REFLEN];
String s_query(buf, sizeof(buf), system_charset_info);
s_query.copy(stub, sizeof(stub) - 1, system_charset_info);
/*
Insertion sort of temporary tables by pseudo_thread_id to build ordered
list of sublists of equal pseudo_thread_id.
*/
All_tmp_tables_list::Iterator it_sorted(*temporary_tables);
All_tmp_tables_list::Iterator it_unsorted(*temporary_tables);
uint sorted_count= 0;
while((share= it_unsorted++))
{
if (IS_USER_TABLE(share))
{
prev_sorted= NULL;
if (!found_user_tables) found_user_tables= true;
for (uint i= 0; i < sorted_count; i ++)
{
sorted= it_sorted ++;
if (!IS_USER_TABLE(sorted) ||
(tmpkeyval(sorted) > tmpkeyval(share)))
{
/*
Insert this share before the current element in
the sorted part of the list.
*/
temporary_tables->remove(share);
if (prev_sorted)
{
temporary_tables->insert_after(prev_sorted, share);
}
else
{
temporary_tables->push_front(share);
}
break;
}
prev_sorted= sorted;
}
it_sorted.rewind();
}
sorted_count ++;
}
/*
We always quote db & table names.
*/
if (found_user_tables &&
!(was_quote_show= MY_TEST(variables.option_bits &
OPTION_QUOTE_SHOW_CREATE)))
{
variables.option_bits |= OPTION_QUOTE_SHOW_CREATE;
}
/*
Scan sorted temporary tables to generate sequence of DROP.
*/
share= temporary_tables->pop_front();
while (share)
{
if (IS_USER_TABLE(share))
{
bool save_thread_specific_used= thread_specific_used;
my_thread_id save_pseudo_thread_id= variables.pseudo_thread_id;
char db_buf[FN_REFLEN];
String db(db_buf, sizeof(db_buf), system_charset_info);
/*
Set pseudo_thread_id to be that of the processed table.
*/
variables.pseudo_thread_id= tmpkeyval(share);
db.copy(share->db.str, share->db.length, system_charset_info);
/*
Reset s_query() if changed by previous loop.
*/
s_query.length(sizeof(stub) - 1);
/*
Loop forward through all tables that belong to a common database
within the sublist of common pseudo_thread_id to create single
DROP query.
*/
for (;
share && IS_USER_TABLE(share) &&
tmpkeyval(share) == variables.pseudo_thread_id &&
share->db.length == db.length() &&
memcmp(share->db.str, db.ptr(), db.length()) == 0;
/* Get the next TABLE_SHARE in the list. */
share= temporary_tables->pop_front())
{
/*
We are going to add ` around the table names and possible more
due to special characters.
*/
append_identifier(this, &s_query, &share->table_name);
s_query.append(',');
rm_temporary_table(share->db_type(), share->path.str);
free_table_share(share);
my_free(share);
}
clear_error();
CHARSET_INFO *cs_save= variables.character_set_client;
variables.character_set_client= system_charset_info;
thread_specific_used= true;
Query_log_event qinfo(this, s_query.ptr(),
s_query.length() - 1 /* to remove trailing ',' */,
false, true, false, 0);
qinfo.db= db.ptr();
qinfo.db_len= db.length();
variables.character_set_client= cs_save;
get_stmt_da()->set_overwrite_status(true);
transaction.stmt.mark_dropped_temp_table();
if ((error= (mysql_bin_log.write(&qinfo) || error)))
{
/*
If we're here following THD::cleanup, thence the connection
has been closed already. So lets print a message to the
error log instead of pushing yet another error into the
stmt_da.
Also, we keep the error flag so that we propagate the error
up in the stack. This way, if we're the SQL thread we notice
that THD::close_tables failed. (Actually, the SQL
thread only calls THD::close_tables while applying
old Start_log_event_v3 events.)
*/
sql_print_error("Failed to write the DROP statement for "
"temporary tables to binary log");
}
get_stmt_da()->set_overwrite_status(false);
variables.pseudo_thread_id= save_pseudo_thread_id;
thread_specific_used= save_thread_specific_used;
}
else
{
free_tmp_table_share(share, true);
/* Get the next TABLE_SHARE in the list. */
share= temporary_tables->pop_front();
}
}
if (!was_quote_show)
{
/*
Restore option.
*/
variables.option_bits&= ~OPTION_QUOTE_SHOW_CREATE;
}
DBUG_RETURN(error);
}
/**
Delete the files and free the specified table share.
@param share [IN] TABLE_SHARE to free
@param delete_table [IN] Whether to delete the table files?
@return void
*/
void THD::free_tmp_table_share(TMP_TABLE_SHARE *share,
bool delete_table)
{
DBUG_ENTER("THD::free_tmp_table_share");
if (delete_table)
{
rm_temporary_table(share->db_type(), share->path.str);
}
free_table_share(share);
my_free(share);
DBUG_VOID_RETURN;
}
/**
Free the specified table object.
@param table [IN] Table object to free.
@return void
*/
void THD::free_temporary_table(TABLE *table)
{
DBUG_ENTER("THD::free_temporary_table");
/*
If LOCK TABLES list is not empty and contains this table, unlock the table
and remove the table from this list.
*/
mysql_lock_remove(this, lock, table);
close_temporary_table(table);
DBUG_VOID_RETURN;
}
/**
On replication slave, acquire the Relay_log_info's data_lock and use slave
temporary tables.
@return true Lock acquired
false Lock wasn't acquired
*/
bool THD::lock_temporary_tables()
{
DBUG_ENTER("THD::lock_temporary_tables");
/* Do not proceed if a lock has already been taken. */
if (m_tmp_tables_locked)
{
DBUG_RETURN(false);
}
if (rgi_slave)
{
mysql_mutex_lock(&rgi_slave->rli->data_lock);
temporary_tables= rgi_slave->rli->save_temporary_tables;
m_tmp_tables_locked= true;
}
DBUG_RETURN(m_tmp_tables_locked);
}
/**
On replication slave, release the Relay_log_info::data_lock previously
acquired to use slave temporary tables.
@return void
*/
void THD::unlock_temporary_tables()
{
DBUG_ENTER("THD::unlock_temporary_tables");
if (!m_tmp_tables_locked)
{
DBUG_VOID_RETURN;
}
if (rgi_slave)
{
rgi_slave->rli->save_temporary_tables= temporary_tables;
temporary_tables= NULL; /* Safety */
mysql_mutex_unlock(&rgi_slave->rli->data_lock);
m_tmp_tables_locked= false;
}
DBUG_VOID_RETURN;
}
|