summaryrefslogtreecommitdiff
path: root/doc/FAQ_chinese
blob: e39c0c77a9f55d5cf9a898af5e989f777a6721dc (plain)
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

                          PostgreSQL ³£¼ûÎÊÌ⣨FAQ£©
                                       
   ×î½ü¸üУº2003 Äê 01 Ô 06 ÈÕ ÐÇÆÚÒ» 22:27:35 CST
   
   Ŀǰά»¤ÈËÔ±£ºBruce Momjian (pgman@candle.pha.pa.us)
   ÖÐÎİæÎ¬»¤ÈËÔ±£ººÎΰƽ £¨laser@pgsqldb.com £©
   
   ±¾ÎĵµµÄ×îа汾¿ÉÒÔÔÚhttp://www.postgresql.org/files/documentation/fa
   qs/FAQ.html ²é¿´¡£
   
   ²Ù×÷ϵͳƽ̨Ïà¹ØµÄÎÊÌâÔÚhttp://www.postgresql.org/docs/faq/Àï»Ø´ð¡£
     _________________________________________________________________
   
                                  ³£¼ûÎÊÌâ
                                      
   1.1) PostgreSQL ÊÇʲô£¿¸ÃÔõô·¢Òô£¿
   1.2) PostgreSQL µÄ°æÈ¨ÊÇʲô?
   1.3) PostgreSQL ÔËÐÐÔÚʲô Unix ƽ̨ÉÏ£¿
   1.4) ¿ÉÓÃµÄ·Ç Unix ƽ̨ÓÐÄÇЩ£¿
   1.5) ÎÒ´ÓÄÄÀïÄܵõ½ PostgreSQL£¿
   1.6) ÎÒ´ÓÄÄÀïÄܵõ½¶Ô PostgreSQL µÄÖ§³Ö£¿
   1.7) PostgreSQL ×îеİ汾ÊÇʲô£¿
   1.8) ÓÐÄÄЩ¿ÉÓÃµÄ PostgreSQL µÄÎĵµ£¿
   1.9) ÎÒÈçºÎÁ˽âÒÑÖªµÄ BUG »òȱʧµÄÌØÐÔ£¿
   1.10) ÎÒÓ¦¸ÃÔõÑùѧϰ SQL £¿
   1.11) PostgreSQL ÊÇ Y2K ¼æÈݵÄÂð£¿
   1.12) ÎÒÓ¦¸ÃÔõÑù¼ÓÈ뿪·¢¶ÓÎ飿
   1.13) ÎÒÓ¦¸ÃÔõÑùÌá½»Ò»¸ö BUG ±¨¸æ£¿
   1.14) PostgreSQL ºÍÆäËû DBMS ±ÈÆðÀ´ÈçºÎ£¿
   1.15) ÎÒÓ¦¸ÃÔõÑùÔÞÖú PostgreSQL £¿
   
                               Óû§¿Í»§¶ËÎÊÌâ
                                      
   2.1) ÓÐ PostgreSQL µÄ ODBC Çý¶¯³ÌÐòô£¿
   2.2) ÓÐʲô¹¤¾ß¿ÉÒÔ°Ñ PostgreSQL ÓÃÓÚ Web Ò³Ãæ£¿
   2.3) PostgreSQL ÓµÓÐͼÐÎÓû§½çÃæÂð£¿
   2.4) ÎÒÃÇ¿ÉÒÔÓÃʲôÓïÑÔºÍ PostgreSQL ´ò½»µÀ£¿
   
                                ϵͳ¹ÜÀíÎÊÌâ
                                      
   3.1) ÎÒÔõÑùÄÜ°Ñ PostgreSQL ×°ÔÚ /usr/local/pgsql ÒÔÍâµÄµØ·½£¿
   3.2) µ±ÎÒÔËÐÐ postmaster ʱ£¬³öÏÖ Bad System Call£¨ÏµÍ³µ÷ÓÃ´í£©»ò Core
   Dumped ´íÎó¡£ÎªÊ²Ã´£¿
   3.3) µ±ÎÒÊÔͼÔËÐÐ postmaster ʱ£¬³öÏÖ IpcMemoryCreate ´íÎó¡£ÎªÊ²Ã´£¿
   3.4) µ±ÎÒÊÔͼÔËÐÐ postmaster ʱ£¬³öÏÖ IpcSemaphoreCreate
   ´íÎó¡£ÎªÊ²Ã´£¿
   3.5) ÎÒÈçºÎ¿ØÖÆÀ´×ÔÆäËûÖ÷»úµÄÁ¬½Ó£¿
   3.6) ÎÒÔõÑùµ÷ÕûÊý¾Ý¿âÒýÇæÒÔ»ñµÃ¸üºÃµÄÐÔÄÜ£¿
   3.7) PostgreSQL Àï¿ÉÒÔ»ñµÃʲôÑùµÄµ÷ÊÔÌØÐÔ£¿
   3.8) ΪʲôÔÚÊÔͼÁ¬½ÓµÇ¼ʱÊÕµ½¡°Sorry, too many clients¡± ÏûÏ¢£¿
   3.9) pgsql_tmp Ŀ¼Àï¶¼ÓÐЩʲô£¿
   3.10) ΪʲôҪÔÚÉý¼¶ PostgreSQL ·¢²¼°æ±¾Ê±×ö dump ºÍ restore £¿
   
                                  ²Ù×÷ÎÊÌâ
                                      
   4.1) ¶þ½øÖÆÓαêºÍÆÕͨÓαêÖ®¼äµÄÇø±ðÊÇʲô£¿
   4.2) ÈçºÎֻѡÔñÒ»¸ö²éѯ½á¹ûµÄÍ·¼¸ÐУ¿
   4.3) ÎÒÈçºÎ»ñȡһ¸öÊý¾Ý¿âÖбíµÄÁÐ±í£¬»òÕßÊÇÆäËûÎÒÄÜÔÚ psql
   Àï¿´µ½µÄ¶«Î÷£¿
   4.4) ÔõÑù´Ó±íÀïÃæÉ¾³ýÒ»ÁУ¿
   4.5) Ò»ÐУ¬Ò»¸ö±í£¬Ò»¸ö¿âµÄ×î´ó³ß´çÊǶàÉÙ£¿
   4.6) ´æ´¢Ò»¸öµäÐ͵ÄÎı¾ÎļþÀïµÄÊý¾ÝÐèÒª¶àÉÙ´ÅÅ̿ռ䣿
   4.7) ÈçºÎ²é¿´±í¡¢Ë÷Òý¡¢Êý¾Ý¿âÒÔ¼°Óû§µÄ¶¨Ò壿
   4.8) ÎҵIJéѯºÜÂý»òÕßûÓÐÀûÓÃË÷Òý¡£ÎªÊ²Ã´£¿
   4.9) ÎÒÈçºÎ²ÅÄÜ¿´µ½²éѯÓÅ»¯Æ÷ÊÇÔõÑù´¦ÀíÎҵIJéѯµÄ£¿
   4.10) R-tree Ë÷ÒýÊÇʲô£¿
   4.11) ʲôÊÇ»ùÒò²éѯÓÅ»¯£¨Genetic Query Optimization£©£¿
   4.12)
   ÎÒÔõÑù×öÕýÔò±í´ïʽËÑË÷ºÍ´óСдÎ޹صÄÕýÔò±í´ïʽ²éÕÒ£¿ÔõÑùÀûÓÃË÷Òý½øÐдó
   СдÎ޹زéÕÒ£¿
   4.13) ÔÚÒ»¸ö²éѯÀÎÒÔõÑù¼ì²âÒ»¸ö×Ö¶ÎÊÇ·ñΪ NULL£¿
   4.14) ¸÷ÖÖ×Ö·ûÀàÐÍÖ®¼äÓÐʲô²»Í¬£¿
   4.15.1) ÎÒÔõÑù´´½¨Ò»¸öÐòÁкÅ/×Ô¶¯µÝÔöµÄ×ֶΣ¿
   4.15.2) ÎÒÈçºÎ»ñµÃÒ»¸ö²åÈëµÄÐòÁкŵÄÖµ£¿
   4.15.3) ʹÓà currval() ºÍ nextval() »áµ¼ÖÂºÍÆäËûÓû§µÄÎÉÂÒÇé¿ö£¨race
   condition£©Âð£¿
   4.15.4)
   Ϊʲô²»ÔÚÊÂÎñÒì³£ÖÐÖ¹ºóÖØÓÃÐòÁкÅÄØ£¿ÎªÊ²Ã´ÔÚÐòÁкÅ×ֶεÄȡֵÖдæÔÚ¼ä
   ¶ÏÄØ£¿
   4.16) ʲôÊÇ OID£¿Ê²Ã´ÊÇ TID £¿
   4.17) PostgreSQL ʹÓõÄһЩÊõÓïµÄº¬ÒåÊÇʲô£¿
   4.18) ΪʲôÎÒÊÕµ½´íÎó¡°ERROR: Memory exhausted in AllocSetAlloc()¡±£¿
   4.19) ÎÒÈçºÎ²ÅÄÜÖªµÀËùÔËÐÐµÄ PostgreSQL µÄ°æ±¾£¿
   4.20) ΪʲôÎҵĴó¶ÔÏó²Ù×÷µ¼Ö´íÎó¡°invalid large obj
   descriptor¡±£¨·Ç·¨µÄ´ó¶ÔÏóÃèÊö·û£©£¿
   4.21) ÎÒÈçºÎ´´½¨Ò»¸öȱʡֵÊǵ±Ç°Ê±¼äµÄ×ֶΣ¿
   4.22) ΪʲôʹÓà IN µÄ×Ó²éѯÕâôÂý£¿
   4.23) ÈçºÎ½øÐÐ outer join £¨ÍâÁ¬½Ó£©£¿
   4.24) ÈçºÎʹÓÃÉæ¼°¶à¸öÊý¾Ý¿âµÄ²éѯ£¿
   4.25) ÈçºÎÈú¯Êý·µ»Ø¶àÐлò¶àÁУ¿
   4.26) ΪʲôÔÚ PL/PgSQL º¯ÊýÖв»Äܿɿ¿µØ´´½¨»òɾ³ýÁÙʱ±í£¿
   4.27) ÓÐÄÄЩÊý¾Ý¸´ÖÆÑ¡Ï
   4.28) ÓÐÄÄЩÊý¾Ý¼ÓÃÜÑ¡Ï
   
                              À©Õ¹ PostgreSQL
                                      
   5.1) ÎÒдÁËÒ»¸öÓû§¶¨Ò庯Êý¡£µ±ÎÒÔÚ psql ÀïÔËÐÐʱ£¬ÎªÊ²Ã´»áµ¼Ö core
   dump£¿
   5.2) ÎÒÈçºÎÄܸø PostgreSQL ¹±Ï×һЩͦ²»´íµÄÐÂÀàÐͺͺ¯Êý£¿
   5.3) ÎÒÔõÑùдһ¸ö·µ»ØÒ»Ìõ¼Ç¼µÄ C º¯Êý£¿
   5.4) ÎÒÐÞ¸ÄÁËÒ»¸öÔ´Îļþ£¬ÎªÊ²Ã´ÖØÐ±àÒëºóûÓп´µ½¸Ä±ä£¿
     _________________________________________________________________
   
                                  ³£¼ûÎÊÌâ
                                      
    1.1) PostgreSQL ÊÇʲô£¿¸ÃÔõô·¢Òô£¿
    
   PostgreSQL ¶Á×÷ Post-Gres-Q-L ¡£
   
   PostgreSQL ÊÇÏÂÒ»´ú DBMS µÄÑо¿ÔÐÍ POSTGRES
   Êý¾Ý¿â¹ÜÀíϵͳµÄÔöÇ¿°æ¡£PostgreSQL ÔÚ±£³Ö POSTGRES
   µÄÇ¿´óµÄÊý¾ÝÄ£ÐͺͷḻµÄÊý¾ÝÀàÐ͵Ļù´¡ÉÏ£¬ÓÃÒ»¸öÀ©Õ¹Á赀 SQL
   ×Ó¼¯È¡´úÁËÔÏ鵀 PostQuel ²éѯÓïÑÔ¡£PostgreSQL
   ÊÇ×ÔÓɵIJ¢ÇÒËùÓÐÔ´´úÂë¶¼¿ÉÒÔ»ñµÃ¡£
   
   PostgreSQL µÄ¿ª·¢ÓÉ²Î¼Ó PostgreSQL
   ¿ª·¢ÓʼþÁбíµÄÒ»¸ö¿ª·¢ÈËԱС×é½øÐС£Ä¿Ç°µÄе÷ÈËÊÇ Marc G. Fournier
   £¨scrappy@postgreSQL.org
   £©¡££¨¹ØÓÚÈçºÎ¼ÓÈë²Î¼û1.6½Ú£©¡£Õâ¸ö¶ÓÎéÏÖÔÚ¸ºÔð PostgreSQL
   µÄËùÓпª·¢¡£
   
   PostgreSQL 1.01 µÄ×÷ÕßÊÇ Andrew Yu ºÍ Jolly
   Chen¡£»¹ÓÐÐí¶àÆäËûÈËÎªÒÆÖ²£¬²âÊÔ£¬µ÷ÊÔºÍÔöÇ¿´úÂë×öÁË´óÁ¿¹±Ïס£PostgreS
   QL µÄ×î³õÆðÔ´ Postgres£¬ÊÇÔÚ¼ÓÖÝ´óѧ²®¿ËÀû·ÖУµÄ Michael Stonebraker
   ½ÌÊÚµÄÖ¸µ¼Ï£¬ÓÉÐí¶àÑо¿Éú£¬±¾¿ÆÉúºÍ±à³ÌÖ°Ô±Íê³ÉµÄ¡£
   
   Õâ¸öÈí¼þ×î³õÔÚ²®¿ËÀûµÄÃû×ÖÊÇ Postgres¡£ÔÚ 1995 Ä꣬µ±Ôö¼ÓÁË SQL
   ¹¦Äܺó£¬ËüµÄÃû×Ö¸Ä³É Postgres95¡£ÔÚ 1996ÄêÄ©£¬²Å¸ÄÃûΪ PostgreSQL¡£
   
    1.2) PostgreSQL µÄ°æÈ¨ÊÇʲô?
    
   PostgreSQL ÊÜÏÂÃæµÄ°æÈ¨Ô¼Êø¡£
   
   PostgreSQL Êý¾Ý¿â¹ÜÀíϵͳ
   
   £¨PostgreSQL Data Base Management System£©
   
   ²¿·Ö°æÈ¨£¨c£©1996-2002£¬PostgreSQL È«Çò¿ª·¢Ð¡×é
   ²¿·Ö°æÈ¨£¨c£©1994-6 ¼ÓÖÝ´óѧ¶ÊÂ
   
   £¨Portions copyright (c) 1996-2002, PostgreSQL Global Development
   Group
    Portions Copyright (c) 1994-6 Regents of the University of
   California£©
   
   ÔÊÐíΪÈκÎÄ¿µÄʹÓ㬿½±´£¬Ð޸ĺͷַ¢Õâ¸öÈí¼þºÍËüµÄÎĵµ¶ø²»ÊÕÈ¡ÈκηÑÓÃ
   £¬²¢ÇÒÎÞÐëÇ©ÊðÒò´Ë¶ø²úÉúµÄÖ¤Ã÷£¬Ç°ÌáÊÇÉÏÃæµÄ°æÈ¨ÉùÃ÷ºÍ±¾¶ÎÒÔ¼°ÏÂÃæÁ½¶Î
   ÎÄ×Ö³öÏÖÔÚËùÓп½±´ÖС£
   
   £¨Permission to use, copy, modify, and distribute this software and
   its documentation for any purpose, without fee, and without a written
   agreement is hereby granted, provided that the above copyright notice
   and this paragraph and the following two paragraphs appear in all
   copies.£©
   
   ÔÚÈκÎÇé¿öÏ£¬¼ÓÖÝ´óѧ¶¼²»³Ðµ£ÒòʹÓôËÈí¼þ¼°ÆäÎĵµ¶øµ¼ÖµĶÔÈκε±ÊÂÈË
   µÄÖ±½ÓµÄ£¬¼ä½ÓµÄ£¬ÌØÊâµÄ£¬¸½¼ÓµÄ»òÕßÏà°é¶øÉúµÄË𻵣¬°üÀ¨ÀûÒæËðʧµÄÔðÈÎ
   £¬¼´Ê¹¼ÓÖÝ´óѧÒѾ½¨ÒéÁËÕâЩËðʧµÄ¿ÉÄÜÐÔʱҲÊÇÈç´Ë¡£
   
   £¨IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY
   PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
   DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS
   SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA
   HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.£©
   
   ¼ÓÖÝ´óѧÃ÷È··ÅÆúÈκα£Ö¤£¬°üÀ¨µ«²»¾ÖÏÞÓÚÄ³Ò»ÌØ¶¨ÓÃ;µÄÉÌÒµºÍÀûÒæµÄÒþº¬
   ±£Ö¤¡£ÕâÀïÌṩµÄÕâ·ÝÈí¼þÊÇ»ùÓÚ¡°µ±×÷ÊÇ¡±µÄ»ù´¡µÄ£¬Òò¶ø¼ÓÖÝ´óѧûÓÐÔðÈÎ
   Ìṩά»¤£¬Ö§³Ö£¬¸üУ¬ÔöÇ¿»òÕßÐ޸ĵķþÎñ¡£
   
   £¨THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
   PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
   CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
   UPDATES, ENHANCEMENTS, OR MODIFICATIONS.£©
   ÉÏÃæ¾ÍÊÇ BSD °æÈ¨ÉùÃ÷£¬Ò»¸ö¾­
   µäµÄ¿ªÔ´°æÈ¨ÉùÃ÷¡£Ëü¶ÔÔ´´úÂëµÄʹÓÃδ×÷ÈκÎÏÞÖÆ¡£ÎÒÃÇϲ»¶Ëü²¢ÇÒ²»´òËã¸Ä
   ±äËü¡£
   
    1.3) PostgreSQL ÔËÐÐÔÚʲô Unix ƽ̨ÉÏ£¿
    
   Ò»°ã˵À´£¬Ò»¸öÏÖ´úµÄ UNIX ¼æÈÝµÄÆ½Ì¨¶¼ÄÜÔËÐÐ PostgreSQL
   ¡£ÔÚ°²×°Ö¸ÄÏÀïÁгöÁË·¢²¼Ê±¾¹ýÃ÷È·²âÊÔµÄÆ½Ì¨¡£
   
    1.4) ¿ÉÓÃµÄ·Ç Unix ƽ̨ÓÐÄÄЩ£¿
    
   ¿Í»§¶Ë
   
   °Ñ libpq C ¿â£¬psql£¬ÆäËû½Ó¿ÚºÍ¿Í»§¶ËÓ¦ÓóÌÐò±àÒë³É¿ÉÒÔÔÚ MS Windows
   ƽ̨ÉÏÔËÐÐÊÇ¿ÉÄܵġ£ÕâÖÖÇé¿öÏ£¬¿Í»§¶ËÔÚ MS Windows ÉÏÔËÐУ¬²¢ÇÒͨ¹ý
   TCP/IP ÓëÒ»¸öÔËÐÐÔÚÎÒÃÇÖ§³ÖµÄ Unix
   ƽ̨ÉϵķþÎñÆ÷½øÐÐͨѶ¡£·¢²¼°æ±¾Öаüº¬Ò»¸öÎļþ win32.mak ÓÃÓÚÉú³É
   Win32 libpq ¿âºÍ psql ¡£PostgreSQL Ò²¿ÉÒÔºÍ ODBC ¿Í»§¶ËͨѶ¡£
   
   ·þÎñÆ÷
   
   Êý¾Ý¿â·þÎñÆ÷ÏÖÔÚ¿ÉÒÔͨ¹ý Cygwin £¬Cygnus µÄ Unix/NT ÒÆÖ²¿âÔÚ Windows
   NT ºÍ Win2k ÉÏÔËÐС£²ÎÔÄ·¢²¼°æ±¾ÀïµÄ See pgsql/doc/FAQ_MSWIN Îļþ»ò
   http://www.PostgreSQL.org/docs/faq-mswin.html ¡£
   
   ÒÆÖ²µ½ MS Win NT/2000/XP µÄ±¾»ú°æµÄ¹¤×÷ÕýÔÚ½øÐС£
   
    1.5) ÎÒ´ÓÄÄÀïÄܵõ½ PostgreSQL£¿
    
   PostgreSQL µÄÖ÷ÄäÃûFTPÕ¾µãÊÇ
   ftp://ftp.PostgreSQL.org/pub£¬¾µÏñÕ¾µã¿ÉÒԲο¼ÎÒÃÇÍøÕ¾µÄÖ÷Ò³¡£
   
    1.6) ÎÒ´ÓÄÄÀïÄܵõ½¶Ô PostgreSQL µÄÖ§³Ö£¿
    
   Ö÷ÒªµÄÓʼþÁбíÊÇ£ºpgsql-general@postgreSQL.org¡£¿ÉÒÔÔÚÄÇÀïÌÖÂÛÓйØ
   PostgreSQL µÄÎÊÌâ¡£Òª¼ÓÈëÁÐ±í£¬·¢Ò»·âÓʼþÄÚÈÝ£¨²»ÊÇÖ÷ÌâÐУ©Îª
        subscribe
        end

   µÄÓʼþµ½ pgsql-general-request@postgreSQL.org ¡£
   
   »¹¿ÉÒÔ»ñȡժҪÁÐ±í¡£Òª¼ÓÈëÕâ¸öÁÐ±í£¬·¢Óʼþµ½£ºpgsql-general-digest-req
   uest@postgreSQL.org£¬ÆäÄÚÈÝΪ£º
        subscribe
        end

   ÿµ±Ö÷Áбí´ïµ½´óÔ¼ 30k µÄÏûÏ¢ÄÚÈÝʱ£¬ÕªÒª¾Í·¢Ë͸øÕâ¸öÁбíµÄ³ÉÔ±¡£
   
   »¹¿ÉÒԲμӳô³æÓʼþÁÐ±í¡£Òª¼ÓÈëÕâ¸öÁÐ±í£¬·¢ËÍÒ»¸öÓʼþµ½
   bugs-request@postgreSQL.org£¬ÄÚÈÝΪ£º
        subscribe
        end

   »¹¿ÉÒԲμӿª·¢ÈËÔ±ÓʼþÁÐ±í¡£Òª¼ÓÈëÕâ¸öÁÐ±í£¬·¢ËÍÒ»¸öÓʼþµ½
   hackers-request@postgreSQL.org£¬ÄÚÈÝΪ£º
        subscribe
        end

   ÆäËûµÄ¹ØÓÚ PostgreSQL ÓʼþÁбíºÍÆäËûÐÅÏ¢¿ÉÒÔÔÚ PostgreSQL µÄ WWW
   Ö÷Ò³ÕÒµ½£º
   
     http://postgresql.org/
     
   ÔÚ EFNet ÀﻹÓÐÒ»¸ö IRC ƵµÀ£¬ÆµµÀ #PostgreSQL¡£ÎÒÓà unix ÃüÁîirc -c
   '#PostgreSQL' "$USER" irc.phoenix.net
   
   ÉÌÒµÖ§³Ö¹«Ë¾µÄÁбíÔÚ
   http://www.PostgreSQL.org/users-lounge/commercial-support.html ¡£
   
    1.7) PostgreSQL ×îеİ汾ÊÇʲô£¿
    
   PostgreSQL ×îеİ汾Êǰ汾 7.2.3¡££¨Òë×¢£ºÏÖÔÚÓ¦¸ÃÊÇ 7.3.1 ÁË¡££©
   
   ÎÒÃǼƻ®Ã¿ËĸöÔ·¢²¼Ò»¸öÖ÷Òª°æ±¾¡£
   
    1.8) ÓÐÄÄЩ¿ÉÓÃµÄ PostgreSQL µÄÎĵµ£¿
    
   ÔÚ·¢²¼°üÀïÓÐһЩÊֲᣬÊÖ²áÒ³ºÍһЩСµÄ²âÊÔÀý×Ó¡£²Î¼û /doc
   Ŀ¼¡££¨Òë×¢£ºÓ¦Îª $PGHOME/doc£©¡£Ä㻹¿ÉÒÔÔÚÏßä¯ÀÀ PostgreSQL
   µÄÊֲᣬÔÚ http://www.PostgreSQL.org/users-lounge/docs/ ¡£
   
   ÓÐÁ½±¾¹ØÓÚ PostgreSQL µÄÊéÔÚÏßÌṩ£¬ÔÚ
   http://www.PostgreSQL.org/docs/awbook.html ºÍ
   http://www.commandprompt.com/ppbook/ ¡£ÔÚ
   http://www.ca.PostgreSQL.org/books/ ÉÏÓйØÓÚ PostgreSQL
   µÄ¿É¹ºÊé¼®µÄÁÐ±í¡£ÔÚ http://techdocs.PostgreSQL.org/ ÉÏÊÕ¼¯ÁËÓйØ
   PostgreSQL µÄ¼¼ÊõÎÄÕ¡£
   
   psql ÓÐһЩ²»´íµÄ \d ÃüÁÏÔʾ¹ØÓÚÀàÐÍ£¬²Ù×÷·û£¬º¯Êý£¬¾Û¼¯µÈµÄÐÅÏ¢¡£
   
   ÎÒÃÇµÄ web Õ¾µã°üº¬¸ü¶àµÄÎĵµ£®
   
    1.9) ÎÒÈçºÎÁ˽âÒÑÖªµÄ BUG ºÍȱʧµÄÌØÐÔ£¿
    
   PostgreSQL Ö§³ÖÒ»¸öÀ©Õ¹Á赀 SQL-92 µÄ×Ó¼¯¡£²ÎÔÄÎÒÃÇµÄ TODO
   ÁÐ±í£¬»ñȡһ¸öÒÑÖª³ô³æ£¬È±Ê§ÌØÐÔºÍδÀ´¼Æ»®¡£
   
    1.10) ÎÒÓ¦¸ÃÔõÑùѧϰ SQL£¿
    
   ÔÚ http://www.postgresql.org/docs/awbook.html µÄ¹ØÓÚ PostgreSQL
   µÄÊé½ÌÊÚ SQL¡££¨Òë×¢£ºÎÒÏÂÔØµ½±¾µØÁË¡££©ÔÚ
   http://www.commandprompt.com/ppbook ÓÐÁíÍâÒ»±¾¹ØÓÚ PostgreSQL
   µÄÊé¡£ÔÚhttp://www.intermedia.net/support/sql/sqltut.shtm£¬http://ourw
   orld.compuserve.com/homepages/graeme_birchall/HTM_COOK.HTM  ºÍ
   http://sqlcourse.com ÓÐÒ»¸ö²»´íµÄÈëÃŽ̡̳£
   
   ÁíÒ»¸öÊÇ "Teach Yourself SQL in 21 Days, Second
   Edition"£¨21Ììѧ»áSQL£¬µÚ¶þ°æ£©£¬ÔÚ
   http://members.tripod.com/er4ebus/sql/index.htm
   
   ÎÒÃǵÄÐí¶àÓû§Ï²»¶ The Practical SQL Handbook, Bowman, Judith S., et
   al., Addison-Wesley ¡£ ÆäËûµÄÓÐ The Complete Reference SQL, Groff et
   al., McGraw-Hill ¡£
   
    1.11) PostgreSQL ÊÇ Y2K ¼æÈݵÄÂð£¿
    
   ÊÇ£¬ÎÒÃǺÜÈÝÒ׿ØÖÆ 2000 AD Ö®ºóºÍ 2000 BC ֮ǰµÄÈÕÆÚ¡£
   
    1.12) ÎÒÓ¦¸ÃÔõÑù¼ÓÈ뿪·¢¶ÓÎ飿
    
   Ê×ÏÈ£¬ÏÂÔØ×îеÄÔ´´úÂë²¢ÔĶÁÎÒÃÇ web Õ¾µã»ò·¢²¼°üÖÐµÄ PostgreSQL
   ¿ª·¢ÕßÎĵµ¡£Æä´Î£¬¼ÓÈë pgsql-hackers ºÍ pgsql-patches
   ÓʼþÁÐ±í¡£µÚÈý£¬Ïò pgsql-patches Ìá½»¸ßÖÊÁ¿µÄ²¹¶¡³ÌÐò¡£
   
   ÏÖÔÚ´ó¸ÅÓÐÊ®¼¸¸öÈËÓÐ PostgreSQL CVS ¹éµµ COMMIT µÄȨÏÞ¡£ËûÃǶ¼ÒѾ­
   Ìá½»Á˷dz£¶à¸ßÖÊÁ¿µÄ²¹¶¡ÁË£¬ÒÔÖÁÓÚÏÖÓеÄÌá½»È˺ÜÄѸúÉϽÚ×࣬²¢ÇÒÎÒÃÇÏà
   ÐÅËûÃÇÌá½»µÄ²¹¶¡¶¼ÊǸßÖÊÁ¿µÄ¡£
   
    1.13) ÎÒÓ¦¸ÃÔõÑùÌá½»Ò»¸öBUG±¨¸æ£¿
    
   Çë·ÃÎÊ http://www.PostgreSQL.org/bugs/bugs.php µÄ PostgreSQL BugTool
   Ò³Ãæ, ÄÇÀï¸ø³öÁËÈçºÎÌá½»Ò»¸öBUG±¨¸æµÄÖ¸ÄÏ¡£
   
   ͬÑùÒ²Òª¿´¿´ÎÒÃÇµÄ ftp Õ¾µã
   ftp://ftp.postgreSQL.org/pub£¬¿´ÓÐûÓиüÐ嵀 PostgreSQL °æ±¾»ò²¹¶¡¡£
   
    1.14) PostgreSQL ºÍÆäËû DBMS ±ÈÆðÀ´ÈçºÎ£¿
    
   ÆÀ¼ÛÈí¼þÓкü¸ÖÖ·½·¨£ºÌØÐÔ£¬ÐÔÄÜ£¬¿É¿¿ÐÔ£¬Ö§³ÖºÍ¼Û¸ñ¡£
   
   ÌØÐÔ
          PostgreSQL ÓµÓдóÐÍÉÌÓà DBMS
          Àï´ó¶àÊýÌØÐÔ£¬ÀýÈ磺ÊÂÎñ£¬×Ó²éѯ£¬´¥·¢Æ÷£¬ÊÓͼ£¬Íâ¼ü²Î¿¼ÍêÕûÐÔº
          ͸´ÔÓµÄËøµÈ¡£ÎÒÃÇ»¹ÓÐһЩËüÃÇûÓеÄÌØÐÔ£¬ÈçÓû§¶¨ÒåÀàÐÍ£¬¼Ì³Ð£¬
          ¹æÔòºÍ¶à°æ±¾²¢ÐпØÖÆÒÔ¼õÉÙËøµÄÕùÓõȡ£
          
          
   ÐÔÄÜ
          PostgreSQL
          ºÍÆäËûÉÌÓúͿªÔ´µÄÊý¾Ý¿â¾ßÓÐÀàËÆµÄÐÔÄÜ¡£¶ÔijЩ´¦ÀíËü±È½Ï¿ì£¬¶ÔÆ
          äËûһЩ´¦ÀíËü±È½ÏÂý¡£Óë MySQL »ò¸üÇá±ãµÄÊý¾Ý¿âϵͳ±È½Ï£¬ÎÒÃÇÔÚ
          insert/update ʱÂý£¬ÒòΪÎÒÃÇÓÐÊÂÎñ´¦Àí¡£µ±È» MySQL
          ²»¾ßÓÐÎÒÃÇÔÚÉÏÃæµÄÌØÐÔ
          ¶ÎÀï¸ø³öµÄÈκÎÌØÐÔ¡£ÎÒÃǵÄÖ÷Òª·½ÏòÊǿɿ¿ÐÔºÍÌØÐÔ£¬¾¡¹ÜÎÒÃÇÔÚÿ´
          η¢²¼Ê±²»¶ÏµØ¸Ä½øÐÔÄÜ¡£ÓÐÒ»¸öºÜÓÐȤµÄÍøÒ³±È½ÏÁË PostgreSQL ºÍ
          MySQL http://openacs.org/why-not-mysql.html¡£
          
   ¿É¿¿ÐÔ
          ÎÒÃÇÖªµÀ DBMS
          ±ØÐëÊǿɿ¿µÄ£¬·ñÔòËü¾ÍÒ»µãÓö¼Ã»ÓС£ÎÒÃÇŬÁ¦×öµ½·¢²¼¾­
          ¹ýÈÏÕæ²âÊԵģ¬Îȶ¨µÄ³ô³æ×îÉٵĴúÂ롣ÿ¸ö°æ±¾ÖÁÉÙÓÐÒ»¸öÔ嵀 beta
          ²âÊÔ£¬²¢ÇÒÎÒÃǵķ¢²¼ÀúÊ·ÏÔʾÎÒÃÇ¿ÉÒÔÌṩÎȶ¨µÄ£¬Àι̵ģ¬¿ÉÓÃÓÚÉ
          ú²úʹÓõİ汾¡£ÎÒÃÇÏàÐÅÔÚÕâ·½ÃæÎÒÃÇÓëÆäËûµÄÊý¾Ý¿âÈí¼þÊÇÏ൱µÄ¡£
          
          
   Ö§³Ö
          ÎÒÃǵÄÓʼþÁбíÌṩһ¸ö·Ç³£´óµÄ¿ª·¢ÈËÔ±ºÍÓû§µÄ×éÒÔ°ïÖú½â¾öËùÅöµ
          ½µÄÈκÎÎÊÌâ¡£ÎÒÃDz»Äܱ£Ö¤¿Ï¶¨Äܽâ¾öÎÊÌ⣬Ïà±È֮ϣ¬ÉÌÓà DBMS
          Ò²²¢²»ÊÇ×ÜÄܹ»Ìṩ½â¾ö·½·¨¡£Ö±½ÓÓ뿪·¢ÈËÔ±£¬Óû§Èº£¬ÊÖ²áºÍÔ´³ÌÐ
          ò½Ó´¥Áî PostgreSQL µÄÖ§³Ö±ÈÆäËû DBMS
          »¹ÒªºÃ¡£»¹ÓÐһЩÉÌÒµÐÔµÄÔ¤°ü×°µÄÖ§³Ö£¬¿ÉÒÔ¸øÌṩ¸øÄÇЩÐèÒªµÄÈË¡
          ££¨²ÎÔÄÖ§³Ö FAQ Ìõ¿î 1.6 С½Ú¡££©
          
          
   ¼Û¸ñ
          ÎÒÃǶÔÈκÎÓÃ;¶¼Ãâ·Ñ£¬°üÀ¨ÉÌÓúͷÇÉÌÓÃÄ¿µÄ¡£Äã¿ÉÒÔ²»¼ÓÏÞÖÆµØÏòÄ
          ãµÄ²úÆ·Àï¼ÓÈëÎÒÃǵĴúÂ룬³ýÁËÄÇЩÎÒÃÇÔÚÉÏÃæµÄ°æÈ¨ÉùÃ÷ÀïÉùÃ÷µÄ
          BSD ·ç¸ñµÄ°æÈ¨Íâ¡£
          
    1.15) ÎÒÓ¦¸ÃÔõÑùÔÞÖú PostgreSQL £¿
    
   ×Ô´Ó1996Ä꿪ʼ£¬PostgreSQL ÒѾÓÐÁËÒ»¸öÓÅÐãµÄ×éÖ¯¡£ÕâЩӦ¸Ã¹é¹¦ÓÚ Marc
   Fournier£¬ÊÇËû´´½¨Á˲¢ÔÚÕâЩÄêÒ»Ö±¹ÜÀíÕâ¸ö×éÖ¯¡£
   
   ¶ÔÓÚÒ»¸ö¿ªÔ´ÏîÄ¿À´Ëµ£¬ÖÊÁ¿»ù´¡ÉèÊ©ÊǷdz£ÖØÒªµÄ¡£ËüÄÜ·ÀÖ¹³öÏÖÑÏÖØÑÓ³ÙÏî
   Ŀǰ½øµÄ»ìÂÒ¡£
   
   ÏÔÈ»£¬Õâ¸ö×éÖ¯µÄÔËת³É±¾²»·Æ¡£Î¬³ÖÆäǰ½øÓи÷ÖÖÔ¶ȵġ¢Ò»´ÎÐԵĿªÖ§¡£Èç
   ¹ûÄã»òÕßÄãµÄ¹«Ë¾ÄܽøÐоèÔùÒÔÖ§³ÖÕâÏîÊÂÒµ£¬Çë·ÃÎÊ
   http://store.pgsql.com/shopping/ ½øÐоèÔù¡£
   
   ËäÈ»¸ÃÍøÒ³Ìá¼°ÁË PostgreSQL ¹«Ë¾£¬ÕâЩ¾èÔù½«½öÓÃÓÚÖ§³Ö PostgreSQL
   ÏîÄ¿£¬²¢²»»áÓÃÓÚ×ÊÖúû¸öÌØ¶¨µÄ¹«Ë¾¡£Èç¹ûÄãÔ¸Ò⣬Ҳ¿ÉÒÔÓʼÄ֧Ʊµ½ÁªÏµµØ
   Ö·¡£
     _________________________________________________________________
   
                               Óû§¿Í»§¶ËÎÊÌâ
                                      
    2.1) ÓÐ PostgreSQL µÄ ODBC Çý¶¯Ã´£¿
    
   ÓÐÁ½¸ö ODBC Çý¶¯¿ÉÒÔ»ñµÃ£¬PsqlODBC ºÍ OpenLink ODBC.
   
   ¿ÉÒÔÔÚhttp://gborg.postgresql.org/project/psqlodbc/projdisplay.php
   ÏÂÔØ PsqlODBC ¡£
   
   OpenLink ODBC ¿ÉÒÔ´Ó http://www.openlinksw.com/ »ñµÃ¡£ËüÓëËûÃǵıê×¼
   ODBC ¿Í»§¶ËÈí¼þ¼æÈÝ£¬Òò¶øÄã¿ÉÒÔÔÚÈκÎËûÃÇÖ§³ÖµÄ¿Í»§¶Ëƽ̨£¨Win, Mac,
   Unix, VMS£©ÉÏʹÓà PostgreSQL ODBC¡£
   
   ËûÃÇ¿ÉÄܽ«Õâ¸ö²úÆ·ÏúÊÛ¸øÄÇЩÐèÒªÉÌÒµÖ§³ÖµÄÓû§£¬µ«ÊÇ×ÜÊÇÓÐÒ»¸ö
   freeware £¨×ÔÓÉÈí¼þ£©µÄ°æ±¾¿ÉÒԵõ½¡£ÇëѯÎÊ
   postgres95@openlink.co.uk¡£
   
    2.2) ÓÐʲô¹¤¾ß¿ÉÒÔ°Ñ PostgreSQL ÓÃÓÚ Web Ò³Ãæ£¿
    
   Ò»¸ö½éÉÜÒÔÊý¾Ý¿âΪºǫ́µÄͦ²»´íµÄ Õ¾µãÊÇ£ºhttp://www.webreview.com ¡£
   
   ¶ÔÓÚ Web ¼¯³É£¬PHP ÊÇÒ»¸ö¼«ºÃµÄ½Ó¿Ú¡£ËüÔÚ£ºhttp://www.php.net/ ¡£
   
   ¶ÔÓÚ¸´ÔÓµÄÈÎÎñ£¬ºÜ¶àÈ˲ÉÓà Perl ½Ó¿ÚºÍ CGI.pm »ò mod_perl ¡£
   
    2.3) PostgreSQL ÓµÓÐͼÐÎÓû§½çÃæÂð£¿
    
   Êǵġ£Óм¸¸öÊÊÓÃÓÚ PostgreSQL
   µÄͼÐνӿڡ£°üÀ¨PgAccess£¨http://www.pgaccess.com)£¬PgAdmin II
   £¨http://www.pgadmin.org£¬½öÊÊÓÃÓÚWin32£©£¬ RHDB Admin
   (http://sources.redhat.com/rhdb/£© ÒÔ¼° Rekall
   £¨http://www.thekompany.com/products/rekall/£¬
   רÓеÄ/proprietary)¡£»¹ÓÐPHPPgAdmin
   £¨http://phppgadmin.sourceforge.net/£© £¬Ò»¸ö»ùÓÚ web µÄ PostgreSQL
   ·ÃÎʽӿڡ£
   
   ÎÒÃÇÓÐÒ»¸ö²»´íµÄͼÐÎÓû§½çÃæ£¬³ÆÎª PgAccess
   £¬ËüÒ²¿ÉÒÔÓÃ×÷±¨±íÉú³ÉÆ÷¡£ÍøÒ³ÊÇ http://www.pgaccess.org/¡£
   
    2.4) ÎÒÃÇ¿ÉÒÔÓÃʲôÓïÑÔºÍ PostgreSQL ´ò½»µÀ£¿
    
   ´ó¶àÊýÁ÷Ðеıà³ÌÓïÑÔ¶¼ÓзÃÎÊ PostgreSQL
   µÄ½Ó¿Ú¡£Çë¼ì²é±à³ÌÓïÑÔµÄÀ©Õ¹Ä£¿éÁÐ±í¡£
   
   PostgreSQL ·¢²¼°üÖаüº¬ÁËÒÔϽӿڣº
     * C (libpq)
     * Embedded C (ecpg)
     * Java (jdbc)
     * Python (PyGreSQL)
     * TCL (libpgtcl)
       
   ÆäËûµÄ½Ó¿ÚÔÚ http://gborg.postgresql.org É쵀 Drivers/Interfaces
   С½Ú¡£
     _________________________________________________________________
   
                                ϵͳ¹ÜÀíÎÊÌâ
                                      
    3.1) ÎÒÔõÑùÄÜ°Ñ PostgreSQL ×°ÔÚ /usr/local/pgsql ÒÔÍâµÄµØ·½£¿
    
   ÔÚÔËÐÐ configure ʱ¼ÓÉÏ --prefix Ñ¡Ïî¡£
   
    3.2) µ±ÎÒÔËÐÐ postmaster ʱ£¬³öÏÖ Bad System Call£¨ÏµÍ³µ÷ÓÃ´í£©»ò Core
    Dumped ´íÎó¡£ÎªÊ²Ã´£¿
    
   Õâ¿ÉÄÜÊÇºÜ¶à·½ÃæµÄÎÊÌ⣬ÇëÏȼì²é²Ù×÷ϵͳºËÐÄÊÇ·ñÖ§³Ö System V
   À©Õ¹¡£PostgreSQL ÐèÒªÄÚºËÖ§³Ö¹²ÏíÄÚ´æºÍÐźŵơ£
   
    3.3) µ±ÎÒÊÔͼÔËÐÐ postmaster ʱ£¬³öÏÖ IpcMemoryCreate ´íÎó¡£ÎªÊ²Ã´£¿
    
   ÄãҪôÊÇûÓÐÔÚÄÚºËÀïÕýÈ·ÅäÖù²ÏíÄڴ棬ҪôÊÇÄãÐèÒªÀ©´óÄãµÄÄں˵ĿÉÓù²
   ÏíÄÚ´æ¡£ÐèÒªµÄ¹²ÏíÄÚ´æ¾ßÌåµÄÊýÁ¿È¡¾öÓÚÄãµÄÌåϵ½á¹¹ºÍÄãÅäÖÃÄãµÄ
   postmaster
   ÔËÐÐʱʹÓõĻº³åÇøºÍºó¶Ë½ø³ÌÊýÄ¿¡£¶Ô´ó¶àÊýϵͳ£¬Ê¹ÓÃȱʡ»º³åÇøºÍ½ø³ÌÊý
   Ŀʱ£¬Äã×îÉÙÐèÒª~1MB¡£Óйع²ÏíÄÚ´æºÍÐźŵƵÄÏêϸÐÅÏ¢Çë²Î¿¼ PostgreSQL
   Administrator's Guide ¡£
   
    3.4) µ±ÎÒÊÔͼÔËÐÐ postmaster ʱ£¬³öÏÖ IpcSemaphoreCreate ´íÎó¡£ÎªÊ²Ã´£¿
    
   Èç¹û´íÎóÐÅÏ¢ÊÇ IpcSemaphoreCreate: semget failed (No space left on
   device)£¬ÄÇôÔÒòÊÇÄãµÄÄÚºËûÓÐÅäÖÃ×ã¹»µÄÐźŵÆ×ÊÔ´¡£Postgres
   µÄÿ¸öDZÔڵĺǫ́½ø³Ì¶¼ÐèÒªÒ»¸öÐźŵơ£Ò»¸öÁÙʱµÄ½â¾ö·½·¨ÊÇÒԱȽÏÉٵĺó
   ̨½ø³ÌÊý£¨²ÎÊý£©Æô¶¯ postmaster¡£Ê¹Óÿª¹Ø -N ´øÒ»¸öÉÙÓÚȱʡֵ 32
   µÄ²ÎÊýÔËÐÐ postmaster¡£¸ü³¤¾ÃµÄ½â¾ö·½·¨ÊǼӴóÄãµÄÄÚºËµÄ SEMMNS ºÍ
   SEMMNI ²ÎÊý¡£
   
   ÔÚÊý¾Ý¿â·ÃÎÊÁ¿ºÜ´óʱ£¬ÐźŵƲ»¿ÉÓÿÉÄܵ¼ÖÂϵͳ±ÀÀ£¡£
   
   Èç¹û´íÎóÐÅÏ¢ÊÇÆäËûµÄʲô¶«Î÷£¬Äã¿ÉÄܾ͸ù±¾Ã»ÓÐÔÚÄÚºËÀïÃæÅäÖÃÐźŵÆÖ§³Ö
   ¡£Óйع²ÏíÄÚ´æºÍÐźŵƵÄÏêϸÐÅÏ¢Çë²Î¿¼ PostgreSQL Administrator's
   Guide ¡£
   
    3.5) ÎÒÈçºÎ¿ØÖÆÀ´×ÔÆäËûÖ÷»úµÄÁ¬½Ó£¿
    
   ȱʡʱ£¬PostgreSQL Ö»ÔÊÐíͨ¹ý unix ÓòÌ×½Ó×ÖÀ´×Ô±¾»úµÄÁ¬½Ó¡£³ý·ÇÄãʹÓÃ
   -i ¿ª¹ØÆô¶¯ postmaster£¬²¢ÇÒͨ¹ý¶ÔÓ¦µÄ±à¼ $PGDATA/pg_hba.conf
   Îļþ´ò¿ªÁËÖ÷»úΪ»ù´¡£¨ host-based
   £©µÄÈÏÖ¤£¬·ñÔòÆäËû»úÆ÷ÊDz»ÄÜÓëÄãµÄ»úÆ÷Á¬½ÓµÄ¡£ÕâÑù½«ÔÊÐí TCP/IP Á¬½Ó¡£
   
    3.6) ÎÒÔõÑùµ÷ÕûÊý¾Ý¿âÒýÇæÒÔ»ñµÃ¸üºÃµÄÐÔÄÜ£¿
    
   µ±È»£¬Ë÷Òý¿ÉÒÔ¼ÓËÙ²éѯ¡£EXPLAIN ÃüÁîÔÊÐíÄã¹Û²ì PostgreSQL
   ÈçºÎ½âÊÍÄãµÄ²éѯ£¬ÒÔ¼°Ê¹ÓÃÁËÄÄЩË÷Òý¡£
   
   Èç¹ûÄãÕý´¦ÀíÒ»¶Ñ INSERT£¬¿¼ÂÇʹÓà COPY
   ÃüÁîÒÔ´óÅúÁ¿µÄ·½Ê½½øÐС£ÕâÑù×ö±Èµ¥¶ÀµÄÒ»¸ö¸ö INSERT
   ¿ìµÃ¶à¡£Æä´Î£¬Ã»Óд¦ÓÚ BEGIN WORK/COMMIT
   ÊÂÎñ¿éÖ®¼äµÄÓï¾ä±»ÈÏΪÊôÓÚͬһ¸öÊÂÎñ¡£ÊÔ×ÅÔÚÒ»¸öÊÂÎñ¿éÀïÃæ´¦Àí¸ü¶àµÄÓï
   ¾ä¡£ÕâÑù¿ÉÒÔ¼õÉÙÊÂÎñ´øÀ´µÄ¶îÍ⿪Ïú¡£Í¬Ñù£¬ÔÚ×ö´óÁ¿µÄÊý¾Ý¸Ä±äʱ¿¼ÂÇɾ³ý
   ºÍÖØ½¨Ë÷Òý¡£
   
   »¹Óм¸¸öµ÷½ÚµÄÑ¡Ïî¿ÉÒÔʹÓá£Äã¿ÉÒÔͨ¹ý´ø -o -F Ñ¡ÏîÆô¶¯ postmaster
   À´½ûÖ¹ fsync()¡£ÕâÑù½«±ÜÃâÿ´ÎÊÂÎñºóµ÷Óà fsync() °ÑÊý¾Ýˢе½´ÅÅÌÉÏ¡£
   
   Ä㻹¿ÉÒÔʹÓà postmaster -B
   Ñ¡ÏîÔö¼Óºó¶Ë½ø³ÌʹÓõĹ²ÏíÄڴ滺³åµÄÊýÄ¿¡£Èç¹ûÄã°ÑÕâ¸ö²ÎÊýÉèÖõÃÌ«´ó£¬
   postmaster ¿ÉÄÜÎÞ·¨Æô¶¯£¬ÒòΪÄãÒѾ­
   ³¬¹ýÁËÄãµÄÄÚºËÔÚ¹²ÏíÄÚ´æ¿Õ¼äÉϵÄÏÞÖÆ¡£Ã¿¸ö»º³åÇøÊÇ 8K ²¢ÇÒȱʡ 64
   ¸ö»º³åÇø¡£
   
   Ä㻹¿ÉÒÔʹÓúǫ́½ø³ÌµÄ -S
   Ñ¡ÏîÀ´Ôö¼Óÿ¸öºǫ́½ø³ÌÓÃÓÚÁÙʱÅÅÐòÓõÄ×î´óÄÚ´æÊýÁ¿¡£-S
   ÖµÊÇÒÔK×ֽڼƵģ¬È±Ê¡ÊÇ 512 £¨Ò²¾ÍÊÇ˵£¬512K£©¡£
   
   Ä㻹¿ÉÒÔʹÓà CLUSTER ÃüÁîÀ´°Ñ±íÀïµÄÊý¾Ý°´ÕÕij¸öË÷Òý½øÐоۼ¯´æ·Å¡£²ÎÔÄ
   CLUSTER µÄÊÖ²áÒ³»ñÈ¡¸ü¶àϸ½Ú¡£
   
    3.7) PostgreSQL Àï¿ÉÒÔ»ñµÃʲôÑùµÄµ÷ÊÔÌØÐÔ£¿
    
   PostgreSQL
   Óм¸¸öÌØÐÔÓÃÓÚ±¨¸æ×´Ì¬ÐÅÏ¢£¬ÕâЩÐÅÏ¢¿ÉÄܶԵ÷ÊÔÓÃ;ºÜÓаïÖú¡£
   
   Ê×ÏÈ£¬Í¨¹ý¸½´ø --enable-cassert Ñ¡ÏîÔËÐÐ configure£¬Óкܶà assert()
   ¼à¿Øºǫ́½ø³ÌºÍÔÚ·¢ÉúÄ³Ð©Î´ÔøÔ¤ÁϵÄÏÖÏóʱֹͣ³ÌÐòÔËÐС£
   
   postmaster ºÍ postgres ¶¼ÓÐһЩ¿ÉÓõÄÑ¡Ïî¡£Ê×ÏÈ£¬µ±ÄãÆô¶¯ postmaster
   ʱ£¬È·±£Äã°Ñ±ê×¼Êä³öºÍ±ê×¼´íÎóÊä³ö¶¨Ïòµ½ÁËÒ»¸öÈÕÖ¾ÎļþÀïÈ¥ÁË£¬Ïó£º
        cd /usr/local/pgsql
        ./bin/postmaster >server.log 2>&1 &

   ÕâÑù½«ÔÚ PostgreSQL ¶¥¼¶Ä¿Â¼ÏÂÊä³öÒ»¸ö server.log
   Îļþ¡£Õâ¸öÎļþ°üº¬·þÎñÆ÷Åöµ½µÄÎÊÌâºÍ´íÎóµÄÓÐÓÃÐÅÏ¢¡£postmaster ÓÐÒ»¸ö
   -d Ñ¡Ï¸ÃÑ¡ÏîÔÊÐíÎÒÃÇ»ñµÃ¸ü¶àµÄϸ½Ú»ã±¨¡£-d
   Ñ¡Ïî½ÓÊÜÒ»¸öÊý×Ö±êÃ÷µ÷ÊÔ¼¶±ð¡£ÐèÒª¾¯¸æµÄÊǸߵĵ÷ÊÔ¼¶±ð¿ÉÄÜ»áÉú³É¾Þ´óµÄ
   ÈÕÖ¾Îļþ¡£
   
   Èç¹û postmaster ûÓÐÔËÐУ¬Äã¿ÉÒÔÖ±½ÓÔÚÃüÁîÐÐÉÏÆô¶¯ postgres
   ºǫ́½ø³Ì£¬È»ºóÖ±½Ó¼üÈë SQL Óï¾ä¡£ÎÒÃÇÖ»
   ÍÆ¼öÔÚµ÷ÊÔµÄʱºòÕâô¸É¡£Çë×¢ÒâÕâʱÓû»ÐÐÜÞ¶ø²»ÊǷֺűíʾÓï¾ä½áβ¡£Èç¹û
   Äã´ø×ŵ÷ÊÔ·ûºÅ±àÒ룬Äã¿ÉÒÔʹÓÃÒ»¸öµ÷ÊÔÆ÷¹Û¿´·¢ÉúÁËʲôÊÂÇé¡£ÒòΪºǫ́½ø
   ³ÌûÓÐÓÉ postmaster
   Æô¶¯µÄ£¬Ëü²»ÊǺÍʵ¼ÊµÄÔËÐл·¾³Ò»Ö£¬¶øÇÒËø¶¨/ºǫ́½»»¥ÎÊÌâ¿ÉÄܲ»ÄÜÖØÏÖ¡
   £
   
   Èç¹û postmaster ÒѾÔËÐУ¬¿ÉÔÚÒ»¸ö´°¿ÚÖÐÆô¶¯ psql£¬È»ºóÕÒ³ö psql ¶ÔÓ¦µÄ
   postgres ½ø³ÌµÄ PID¡£Ê¹ÓÃÒ»¸öµ÷ÊÔÆ÷¸½×ÅÔÚÕâ¸ö postgres PID
   ÉÏ¡£Äã¿ÉÒÔÔÚµ÷ÊÔÆ÷ÀïÉèÖöϵ㲢ÇÒ´Ó psql ÀïÖ´Ðвéѯ¡£Èç¹ûÄãÔÚµ÷ÊÔ
   postgres µÄÆô¶¯£¬Äã¿ÉÒÔÉèÖà PGOPTIONS="-W n"£¬È»ºóÆô¶¯
   psql¡£ÕâÑù½«µ¼ÖÂÆô¶¯ÑÓ³Ù n
   Ã룬ÕâÑùÄã¾Í¿ÉÒÔ¸½¼ÓÒ»¸öµ÷ÊÔÆ÷²¢ÇÒ¸ú×ÙÆô¶¯Ë³ÐòµÄ¹ý³Ì¡£
   
   postgres ³ÌÐòÓÐ -s£¬-A£¬ºÍ -t Ñ¡Ïî¿ÉÄÜÔÚµ÷ÊÔºÍÐÔÄܲâÁ¿µÄʱºò·Ç³£ÓÐÓá£
   
   Ä㻹¿ÉÒÔ´ø profiling
   Ö§³Ö±àÒëºǫ́£¬ÒÔ±ã¹Û²ìÄÄЩº¯ÊýÕ¼ÓõÄÖ´ÐÐʱ¼ä½Ï¶à¡£profile Îļþ½«·ÅÔÚ
   pgsql/data/base/dbname Ŀ¼Ï¡£¿Í»§¶Ë profile
   Îļþ½«·ÅÔÚ¿Í»§¶Ëµ±Ç°Ä¿Â¼Ï¡£ÔÚ Linux ÏÂÖ§³Ö profiling
   ÒªÔÚ±àÒëʱ¼ÓÉÏ-DLINUX_PROFILE ¡£
   
    3.8) ΪʲôÔÚÊÔͼÁ¬½ÓµÇ¼ʱÊÕµ½¡°Sorry, too many clients¡±ÏûÏ¢£¿
    
   ÄãÐèÒªÔö´ó postmaster Æô¶¯Ê±Ö§³ÖµÄ²¢·¢ºǫ́½ø³ÌÊý¡£
   
   ȱʡÏÞÖÆÊÇ 32 ½ø³Ì¡£Äã¿ÉÒÔͨ¹ý´ø×ÅÊʵ±µÄ -N Öµ¿ª¹ØÆô¶¯ postmaster
   Ôö¼ÓÕâ¸öÊýÄ¿¡£»òÕßÐÞ¸Ä postgresql.conf Îļþ¡£
   
   ҪעÒâÈç¹ûÄã°Ñ -N ÉèÖÃΪ´óÓÚ 32£¬Äã±ØÐëͬÑùÔö´ó -B£¬³¬¹ýËüȱʡµÄ
   64£»-B ±ØÐë×îÉÙÊÇ -N
   µÄÁ½±¶£¬¶øÇÒΪÁ˸üºÃµÄÐÔÄÜ¿ÉÄÜÒª±ÈÄǸöÊý×ÖÒª´ó¡£¶ÔÓÚ´óÊýÄ¿µÄºó¶Ë½ø³Ì£¬
   Äã¿ÉÄÜ»¹»á·¢ÏÖÄ㻹ÐèÒªÔö¼ÓÐí¶à Unix
   ÄÚºËÅäÖòÎÊýÖµ¡£Òª¼ì²éµÄ¶«Î÷°üÀ¨¹²ÏíÄÚ´æ¿éµÄ×î´ó³ß´ç£¬SHMMAX£¬ÐźŵƵÄ
   ×î´óÊýÄ¿£¬SEMMNS ºÍ
   SEMMNI£¬×î´óµÄ½ø³ÌÊý£¬NPROC£¬µ¥Óû§×î´ó½ø³ÌÊý£¬MAXUPRC£¬ÒÔ¼°´ò¿ªÎļþµÄ
   ×î´óÊýÄ¿£¬NFILE ºÍ NINODE ¡£Postgres ¶ÔÔÊÐíµÄºǫ́½ø³ÌÊýÓÐÏÞÖÆµÄÔ­
   ÒòÊÇΪÁËÈ·±£ÄãµÄϵͳ²»»áÓùâ×ÊÔ´¡£
   
   ÔÚ Postgres ÔçÓÚ 6.5 µÄ°æ±¾£¬×î´óºǫ́½ø³ÌÊýȱʡÊÇ
   64£¬²¢ÇÒ¶ÔËüµÄÐÞ¸ÄÊ×ÏÈÐèÒªÐÞ¸Ä include/storage/sinvaladt.h ÀïµÄ
   MaxBackendId ³£Á¿£¬È»ºóÖØÐ BUILD¡£
   
    3.9) pgsql_tmp Ŀ¼Àï¶¼ÓÐЩʲô£¿
    
   ¸ÃĿ¼Ï±£´æÁ˲éѯִÐÐÆ÷Éú³ÉµÄÁÙʱÎļþ¡£ÀýÈ磬Èç¹ûÐèҪΪÂú×ã ORDER BY
   Ìõ¼þ×öÅÅÐò£¬²¢ÇÒÅÅÐòÐèÒª±Èºǫ́µÄ -S
   ²ÎÊý¸ø³öµÄ¸ü¶àµÄ¿Õ¼ä£¬ÄÇô¾Í»á´´½¨Ò»¸öÁÙʱÎļþ±£´æ¶à³öÀ´µÄÊý¾Ý¡£
   
   ÁÙʱÎļþÓ¦¸Ã×Ô¶¯É¾³ý£¬²»¹ýÈç¹ûÔÚÅÅÐò¹ý³ÌÖкǫ́±ÀÀ£Á˾ͿÉÄÜÁôÏÂÀ´¡£Í£Ö¹
   ²¢ÖØÆð postmaster ½«»áɾ³ýÕâЩÎļþ¡£
   
    3.10) ΪʲôҪÔÚÉý¼¶ PostgreSQL ·¢²¼°æ±¾Ê±×ö dump ºÍ restore £¿
    
   PostgreSQL ¿ª·¢×é¶Ôÿ´ÎСµÄÉý¼¶½ö×öÁ˽ÏÉÙµÄÐÞ¸Ä,Òò´Ë´Ó 7.2 Éý¼¶µ½
   7.2.1 ²»ÐèÒª dump ºÍ restore¡£µ«ÊÇÖ÷ÒªµÄÉý¼¶£¨ÀýÈç´Ó 7.2 µ½
   7.3£©Í¨³£»áÐÞ¸Äϵͳ±íºÍÊý¾Ý±íµÄÄÚ²¿¸ñʽ¡£ÕâЩ±ä»¯Ò»°ã±È½Ï¸´ÔÓ£¬Òò´ËÎÒÃ
   Dz»Î¬Êý¾ÝÎļþµÄÏòºó¼æÈÝ¡£dump
   ½«Êý¾Ý°´ÕÕͨÓõĸñʽÊä³ö£¬Ëæºó¿ÉÒÔ±»ÖØÐ¼ÓÔØ²¢Ê¹ÓÃеÄÄÚ²¿¸ñʽ¡£
   
   ´ÅÅÌÎļþ¸ñʽûÓб仯µÄÉý¼¶£¬¿ÉÒÔÓà pg_upgrade ½Å±¾£¬¶ø²»ÐèÒª×ö dump ºÍ
   restor¡£·¢²¼ËµÃ÷script »áÖ¸Ã÷ pg_upgrade ¶Ô¸Ã´ÎÉý¼¶ÊÇ·ñ¿ÉÓá£
     _________________________________________________________________
   
                                  ²Ù×÷ÎÊÌâ
                                      
    4.1) ¶þ½øÖÆÓαêºÍÆÕͨÓαêÖ®¼äµÄÇø±ðÊÇʲô£¿
    
   ²ÎÔÄ DECLARE ÊÖ²áÒ³»ñÈ¡ÐÅÏ¢¡£
   
    4.2)ÈçºÎÖ» SELECT Ò»¸ö²éѯ½á¹ûµÄÍ·¼¸ÐУ¿
    
   ²ÎÔÄ FETCH ÊÖ²áÒ³£¬»òÕßʹÓà SELECT ... LIMIT....
   
   ¼´Ê¹ÄãÖ»ÐèÒª¿ªÍ·µÄ¼¸ÐУ¬Ò²»áÉæ¼°µ½Õû¸ö²éѯ¡£ÊÔ×ÅʹÓôøÓÐ ORDER BY
   µÄ²éѯ¡£Èç¹ûÓÐÒ»¸öË÷ÒýÓë ORDER BY Æ¥Å䣬PostgreSQL
   ¿ÉÄܾÍÖ»´¦ÀíÒªÇóµÄÍ·¼¸Ìõ¼Ç¼£¬·ñÔò½«¶ÔÕû¸ö²éѯ½øÐд¦ÀíÖ±µ½Éú³ÉÐèÒªµÄÐÐ
   ¡£
   
    4.3) ÎÒÈçºÎ»ñȡһ¸ö±íµÄÁÐ±í£¬»òÕßÊÇÆäËûÎÒÄÜÔÚ psql Àï¿´µ½µÄ¶«Î÷£¿
    
   Äã¿ÉÒÔÔĶÁ psql µÄÔ´´úÂëÎļþpgsql/src/bin/psql/describe.c
   ¡£Ëü°üÀ¨ÎªÉú³É psql µÄ·´Ð±¸ÜÃüÁîµÄÊä³öµÄ SQL ÃüÁî¡£Ä㻹¿ÉÒÔ´ø -E
   Ñ¡ÏîÆô¶¯ psql£¬ÕâÑùËü½«´òÓ¡³öÖ´ÐÐÄã¸ø³öµÄÃüÁîËùÓõIJéѯ¡£
   
    4.4) ÔõÑù´Ó±íÀïÃæÉ¾³ýÒ»ÁУ¿
    
   7.3 ÀïÔö¼ÓÁË ALTER TABLE DROP
   COLUMN£¬ÒÔÖ§³Ö´ËÏÄÜ¡£ÔÚÒÔǰµÄ°æ±¾ÖУ¬¿ÉÒÔÕâÑù×ö£º
    BEGIN;
    LOCK TABLE old_table;
    SELECT ...  -- select all columns but the one you want to remove
    INTO TABLE new_table
    FROM old_table;
    DROP TABLE old_table;
    ALTER TABLE new_table RENAME TO old_table;
    COMMIT;

    4.5) Ò»ÐУ¬Ò»¸ö±í£¬Ò»¸ö¿âµÄ×î´ó³ß´çÊǶàÉÙ£¿
    
   ÏÂÃæÊÇһЩÏÞÖÆ£º
    Ò»¸öÊý¾Ý¿â×î´ó³ß´ç£¿   ÎÞÏÞÖÆ£¨´æÔÚ 1TB µÄÊý¾Ý¿â£©
    Ò»¸ö±íµÄ×î´ó³ß´ç£¿    16TB
    Ò»ÐеÄ×î´ó³ß´ç£¿      1.6TB
     Ò»¸ö×ֶεÄ×î´ó³ß´ç?   1GB
    Ò»¸ö±íÀï×î´óÐÐÊý£¿     ÎÞÏÞÖÆ
    Ò»¸ö±íÀï×î´óÁÐÊý£¿     ¸úÁÐÀàÐÍÓйØ,250-1600
    Ò»¸ö±íÀïµÄ×î´óË÷ÒýÊýÁ¿£¿ÎÞÏÞÖÆ

   µ±È»£¬Êµ¼ÊÉÏûÓÐÕæÕýµÄÎÞÏÞÖÆ£¬»¹ÊÇÒªÊÜ¿ÉÓôÅÅ̿ռ䡢¿ÉÓÃÄÚ´æ/½»»»ÇøµÄÖ
   ÆÔ¼¡£
   
   ±íµÄ×î´ó³ß´ç 16 TB ²»ÐèÒª²Ù×÷ϵͳ¶Ô´óÎļþµÄÖ§³Ö¡£´ó±íÓöà¸ö 1 GB
   µÄÎļþ´æ´¢£¬Òò´ËÎļþϵͳ³ß´çµÄÏÞÖÆÊDz»ÖØÒªµÄ¡£
   
   Èç¹ûȱʡµÄ¿é´óСÔö³¤µ½ 32K £¬×î´óµÄ±í³ß´çºÍ×î´óÁÐÊý¿ÉÒÔÔö¼Ó¡£
   
    4.6)´æ´¢Ò»¸öµäÐÍµÄÆ½ÃæÎļþÀïµÄÊý¾ÝÐèÒª¶àÉÙ´ÅÅ̿ռ䣿
    
   Ò»¸ö Postgres
   Êý¾Ý¿â×î¶à¿ÉÄÜÐèÒªÏ൱ÓÚÔÚÒ»¸öÆ½ÃæÎļþÀï´æ´¢ÏàͬÊý¾ÝµÄ5±¶µÄ´ÅÅ̿ռ䡣
   
   ÀýÈ磬¼ÙÉèÓÐÒ»¸ö 100,000
   ÐеÄÎļþ£¬Ã¿ÐÐÓÐÒ»¸öÕûÊýºÍÒ»¸öÎı¾ÃèÊö¡£¼ÙÉèÎı¾´®µÄƽ¾ù³¤¶Èλ20×Ö½Ú¡£
   Æ½ÃæÎļþÕ¼Óà 2.8 MB¡£´æ·ÅÕâЩÊý¾ÝµÄ PostgreSQL Êý¾Ý¿âÎļþ´óÔ¼ÊÇ 6.4
   MB:
     36 ×Ö½Ú: ÿÐеÄÍ·£¨¹À¼ÆÖµ£©
     24 ×Ö½Ú: Ò»¸öint×ֶκÍÒ»¸öÎı¾ÐÍ×Ö¶Î
   +  4 ×Ö½Ú: Ò³ÃæÄÚÖ¸ÏòÔª×éµÄÖ¸Õë
   ----------------------------------------
     64 ×Ö½ÚÿÐÐ

   PostgreSQL Êý¾ÝÒ³µÄ´óСÊÇ 8192 ×Ö½Ú (8 KB)£¬Ôò£º

   8192 ×Ö½Úÿҳ
   -------------------   =  128 ÐÐ/Êý¾ÝÒ³£¨ÏòÏÂÈ¡Õû£©
     64 ×Ö½ÚÿÐÐ

   100000 Êý¾ÝÐÐ
   --------------------  =  782 Êý¾ÝÒ³£¨ÏòÉÏÈ¡Õû£©
      128 ÐÐÿҳ

   782 Êý¾ÝÒ³ * 8192 ×Ö½Ú/Ò³  =  6,406,144 ×Ö½Ú£¨6.4 MB£©

   Ë÷Òý²»ÐèÒªÕâô¶àµÄ¶îÍâÏûºÄ£¬µ«Ò²È·Êµ°üÀ¨±»Ë÷ÒýµÄÊý¾Ý£¬Òò´ËËüÃÇÒ²¿ÉÄܺÜ
   ´ó¡£
   
   ¿ÕÖµ´æ·ÅÔÚλͼÖУ¬Òò´ËÕ¼ÓúÜÉٵĿռ䡣
   
    4.7) ÈçºÎ²é¿´±í¡¢Ë÷Òý¡¢Êý¾Ý¿âÒÔ¼°Óû§µÄ¶¨Ò壿
    
    psql ÓÐÐí¶à·´Ð±¸ÜÃüÁîÓÃÓÚÏÔʾÕâЩÐÅÏ¢¡£Óà \? ¿´¿´¶¼ÓÐÄÄЩ¡£ÒÔ pg_
   ´òÍ·µÄϵͳ±íÒ²ÃèÊöÁËÕâЩÐÅÏ¢¡£ psql -l ¿ÉÒÔÁгöËùÓеÄÊý¾Ý¿â¡£
   
   Ò²¿ÉÒÔÊÔÊÔÎļþ
   pgsql/src/tutorial/syscat.source¡£ËüÑÝʾÁËÐí¶à´ÓÊý¾Ý¿âϵͳ±íÀï»ñÈ¡ÐÅÏ¢
   ÐèÒªµÄ SELECT¡£
   
    4.8) ÎҵIJéѯºÜÂý»òÕßûÓÐÀûÓÃË÷Òý¡£ÎªÊ²Ã´£¿
    
   ²¢·Çÿ¸ö²éѯ¶¼»á×Ô¶¯Ê¹ÓÃË÷Òý¡£Ö»ÓÐÔÚ±íµÄ´óС³¬¹ýÒ»¸ö×îСֵ£¬²¢ÇÒ²éѯֻ
   Ñ¡Ôñ±íÖнÏС±ÈÀýµÄÐÐʱ²ÉÓÃʹÓÃË÷Òý¡£ÕâÊÇÒòΪË÷ÒýɨÃèÒýÆðµÄËæ¼´´ÅÅÌ´æÈ¡
   ¿ÉÄܱÈÖ±½ÓµØ¶ÁÈ¡±í£¨Ë³ÐòɨÃ裩¸üÂý¡£ÎªÁËÅжÏÊÇ·ñʹÓÃË÷Òý£¬PostgreSQL
   ±ØÐë»ñµÃÓйرíµÄͳ¼ÆÖµ¡£ÕâЩͳ¼ÆÖµ¿ÉÒÔʹÓà VACUUM ANALYZE£¬»ò ANALYZE
   »ñµÃ¡£Ê¹ÓÃͳ¼ÆÖµ£¬ÓÅ»¯Æ÷ÖªµÀ±íÖÐÓжàÉÙÐУ¬¾ÍÄܹ»¸üºÃµØÅжÏÊÇ·ñÀûÓÃË÷Òý
   ¡£Í³¼ÆÖµ¶ÔÈ·¶¨ÓÅ»¯µÄÁ¬½Ó˳ÐòºÍÁ¬½Ó·½·¨Ò²ºÜÓÐÓá£ÔÚ±íµÄÄÚÈÝ·¢Éú±ä»¯Ê±£¬
   Ó¦¶¨ÆÚ½øÐÐͳ¼ÆÖµµÄ»ñÈ¡¡£
   
   Ë÷Òýͨ³£²»ÓÃÓÚ ORDER BY
   »òÖ´ÐÐÁ¬½Ó¡£¶ÔÒ»¸ö´ó±íµÄÒ»´Î˳ÐòɨÃ裬ÔÙ×öÒ»¸öÏÔʽµÄÅÅÐòͨ³£±ÈË÷ÒýɨÃè
   Òª¿ì¡£
   
   µ«ÊÇ£¬ÔÚ LIMIT ºÍ ORDER BY ½áºÏʹÓÃʱ¾­
   ³£»áʹÓÃË÷Òý£¬ÒòΪֻ»á·µ»Ø±íµÄһС²¿·Ö¡£Êµ¼ÊÉÏ£¬ËäÈ» MAX() ºÍ MIN()
   ²¢²»Ê¹ÓÃË÷Òý£¬Í¨¹ý¶Ô ORDER BY ºÍ LLIMIT
   ʹÓÃË÷ÒýÈ¡µÃ×î´óÖµºÍ×îСֵҲÊÇ¿ÉÒԵģº
       SELECT col
       FROM tab
       ORDER BY col [ DESC ]
       LIMIT 1;
   
   µ±Ê¹ÓÃͨÅä·û²Ù×÷£¬ÀýÈç LIKE »ò ~ ʱ£¬Ë÷ÒýÖ»ÄÜÔÚÌØ¶¨µÄÇé¿öÏÂʹÓãº
     * ×Ö·û´®µÄ¿ªÊ¼²¿·Ö±ØÐëÊÇÆÕͨ×Ö·û´®£¬Ò²¾ÍÊÇ˵£º
     * LIKE ģʽ²»ÄÜÒÔ % ´òÍ·¡£
     * ~ £¨ÕýÔò±í´ïʽ£©Ä£Ê½±ØÐëÒÔ ^ ´òÍ·¡£
     * ×Ö·û´®²»ÄÜÒÔÆ¥Åä¶à¸ö×Ö·ûµÄģʽÀà´òÍ·£¬ÀýÈç [a-e]¡£
     * ´óСдÎ޹صIJéÕÒ£¬Èç ILIKE ºÍ ~* µÈ²»Ê¹ÓÃË÷Òý¡£µ«¿ÉÒÔÓà 4.12
       ½ÚÃèÊöµÄº¯ÊýË÷Òý¡£
     * ÔÚ×ö initdb ʱ±ØÐë²ÉÓÃȱʡµÄ±¾µØÉèÖà C locale¡£
       
    4.9) ÎÒÈçºÎ²ÅÄÜ¿´µ½²éѯÓÅ»¯Æ÷ÊÇÔõÑù´¦ÀíÎҵIJéѯµÄ£¿
    
   ²Î¿¼ EXPLAIN ÊÖ²áÒ³¡£
   
    4.10) R-tree Ë÷ÒýÊÇʲô£¿
    
   R-tree Ë÷ÒýÓÃÓÚË÷Òý¿Õ¼äÊý¾Ý¡£Ò»¸ö¹þÏ£Ë÷ÒýÎÞ·¨´¦Àí·¶Î§ËÑË÷¡£¶ø B-tree
   Ë÷ÒýÖ»ÄÜ´¦ÀíһάµÄ·¶Î§ËÑË÷¡£R-tree
   Ë÷Òý¿ÉÒÔ´¦Àí¶àάÊý¾Ý¡£ÀýÈ磬Èç¹û¿ÉÒÔÔÚÒ»¸öÀàÐÍΪ point
   µÄ×Ö¶ÎÉϽ¨Á¢Ò»¸ö R-tree Ë÷Òý£¬ÄÇôϵͳÄܸü¸ßЧµØ»Ø´ðÀàËÆ
   ¡°Ñ¡ÔñÔÚÒ»¸ö³¤·½Ðη¶Î§ÄÚµÄËùÓе㡱¡£
   ÃèÊö×î³õµÄ R-Tree Éè¼ÆµÄÕýʽÂÛÎÄÊÇ£º
   Guttman, A. "R-Trees: A Dynamic Index Structure for Spatial
   Searching." Proc of the 1984 ACM SIGMOD Int'l Conf on Mgmt of Data,
   45-57.
   Ä㻹¿ÉÒÔÔÚ Stonebraker µÄ¡°Readings in Database
   Systems¡±ÀïÕÒµ½ÕâÆªÎÄÕ¡£
   ϵͳÄÚÖÃµÄ R-Tree ¿ÉÒÔ´¦Àí¶à±ßÐκͷ½ÐΡ£ÀíÂÛÉÏ˵£¬R-tree
   ¿ÉÒÔÀ©Õ¹Îª´¦Àí¸ü¶àάÊý¡£²»¹ýÔÚʵ¼ùÉÏ£¬À©Õ¹ R-trees
   ÐèÒªÒ»¶¨µÄ¹¤×÷Á¿£¬¶øÎÒÃÇĿǰûÓÐÈçºÎ×öµÄÎĵµ¡£
   
    4.11) ʲôÊÇ»ùÒò²éѯÓÅ»¯£¨Genetic Query Optimization£©£¿
    
   GEQO Ä£¿é²ÉÓûùÒòËã·¨£¨Genetic
   Algorithm£¬GA£©¼Ó¿ì¶à±íÁ¬½ÓµÄ²éѯÓÅ»¯¡£ËüÔÊÐíͨ¹ý·ÇÇî¾ÙËÑË÷´¦Àí´óµÄÁ¬½
   Ó²éѯ¡£
   
    4.12)
    ÎÒÔõÑù×öÕýÔò±í´ïʽËÑË÷ºÍ´óСдÎ޹صÄÕýÔò±í´ïʽËÑË÷£¿ÔõÑùÀûÓÃË÷Òý½øÐдóСдÎ
    Þ¹ØËÑË÷£¿
    
   ²Ù×÷·û ~ ´¦ÀíÕýÔò±í´ïʽƥÅ䣬¶ø ~*
   ´¦Àí´óСдÎ޹صÄÕýÔò±í´ïʽƥÅä¡£´óдЩÎÞ¹ØµÄ LIKE ±äÖÖ³ÉΪ ILIKE¡£
   ´óСдÎ޹صĵÈʽ±È½Ïͨ³£Ð´×ö£º
       SELECT *
       FROM tab
       WHERE lower(col) = 'abc';
   ÕâÑù½«²»»áʹÓñê×¼µÄË÷Òý¡£µ«ÊÇ¿ÉÒÔ´´½¨Ò»¸ö¿É±»ÀûÓõĺ¯ÊýË÷Òý:
       CREATE INDEX tabindex ON tab (lower(col));
   
    4.13) ÔÚÒ»¸ö²éѯÀÎÒÔõÑù¼ì²âÒ»¸ö×Ö¶ÎÊÇ·ñΪ NULL£¿
    
   Óà IS NULL ºÍ IS NOT NULL ²âÊÔÕâ¸ö×ֶΡ£
   
    4.14) ¸÷ÖÖ×Ö·ûÀàÐÍÖ®¼äÓÐʲô²»Í¬£¿
    
     ÀàÐÍ            ÄÚ²¿Ãû³Æ    ˵Ã÷
     --------------------------------------------------
     "char"        char         1¸ö×Ö·û character
     CHAR(#)      bpchar
   ¶¨³¤×Ö·û´®£¬Êµ¼ÊÊý¾Ý²»×㶨Ò峤¶Èʱ£¬ÒÔ¿Õ¸ñ²¹Æë
     VARCHAR(#)  varchar
   Ö¸¶¨ÁË×î´ó³¤¶È£¬±ä³¤×Ö·û´®£¬²»×㶨Ò峤¶ÈµÄ²¿·Ö²»²¹Æë
     TEXT           text         ´®³¤¶È½öÊÜÐеÄ×î´ó³¤¶ÈÏÞÖÆ
     BYTEA          bytea       ±ä³¤×Ö½ÚÐòÁУ¨±ä³¤µÄ¶þ½øÖÆÊý¾Ý£©
   ÔÚϵͳ±íºÍÔÚһЩ´íÎóÐÅÏ¢ÀïÄ㽫¿´µ½ÄÚ²¿Ãû³Æ¡£
   ÉÏÃæ×îºóËÄÖÖÀàÐÍÊÇ"varlena"£¨±ä³¤£©ÀàÐÍ£¨Ò²¾ÍÊÇ˵£¬¿ªÍ·µÄËĸö×Ö½ÚÊdz¤¶
   È£¬ºóÃæ²ÅÊÇÊý¾Ý£©¡£ÓÚÊÇʵ¼ÊÕ¼ÓõĿռä±ÈÉùÃ÷µÄ´óСҪ¶àһЩ¡£È»¶øÕâЩÀàÐ
   Ͷ¼¿ÉÒÔ±»Ñ¹Ëõ´æ´¢£¬Ò²¿ÉÒÔÓà TOAST
   ÍÑ»ú´æ´¢£¬Òò´Ë´ÅÅ̿ռäÒ²¿ÉÄܱÈÔ¤ÏëµÄÒªÉÙ¡£
   CHAR(n) ×îÊʺÏÓÚ´æ´¢³¤¶È»ù±¾²î²»¶àµÄ×Ö·û´®¡£VARCHAR(n)
   ÔÚ´æ´¢ÏÞÖÆÁË×î´ó³¤¶ÈµÄ±ä³¤×Ö·û´®ÊÇ×îºÃµÄ¡£TEXT
   ÊÊÓÃÓÚ´æ´¢²»ÏÞÖÆ³¤¶ÈµÄ×Ö·û´®£¬×î´ó¿É´ï 1G¡£BYTEA
   ÓÃÓÚ´æ´¢¶þ½øÖÆÊý¾Ý£¬ÓÈÆäÊǰüº¬ NULL
   ×Ö½Ú£¨¶þ½øÖƵÄ0£©µÄÖµ¡£ÕâЩÀàÐ;ßÓÐÀàÐ͵ÄÐÔÄÜ¡£
   
    4.15.1) ÎÒÔõÑù´´½¨Ò»¸öÐòÁкÅ/×Ô¶¯µÝÔöµÄ×ֶΣ¿
    
   PostgreSQL Ö§³Ö SERIAL
   Êý¾ÝÀàÐÍ¡£ËüÔÚ×Ö¶ÎÉÏ×Ô¶¯´´½¨Ò»¸öÐòÁкÍË÷Òý¡£ÀýÈ磬
       CREATE TABLE person (
           id SERIAL,
           name TEXT
           );
   »á×Ô¶¯×ª»»Îª£º
   
       CREATE SEQUENCE person_id_seq;
       CREATE TABLE person (
           id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
           name TEXT
           );
       CREATE UNIQUE INDEX person_id_key ON person ( id );
   ²Î¿¼ create_sequence ÊÖ²áÒ³»ñÈ¡¹ØÓÚÐòÁеĸü¶àÐÅÏ¢¡£Ä㻹¿ÉÒÔÓÃÿÐеÄ
   oid ×Ö¶Î×÷Ϊһ¸öΨһֵ¡£²»¹ý£¬Èç¹ûÄãÐèÒªÇãµ¹ºÍÖØÔØÊý¾Ý¿â£¬ÄãÐèҪʹÓÃ
   pg_dump µÄ -o Ñ¡Ïî»òÕß COPY WITH OIDS Ñ¡ÏîÒÔ±£Áô OID¡£
   
    4.15.2) ÎÒÈçºÎ»ñµÃÒ»¸ö²åÈëµÄÐòÁкŵÄÖµ£¿
    
   Ò»ÖÖ·½·¨ÊÇÔÚ²åÈë֮ǰÏÈÓú¯Êý nextval() ´ÓÐòÁжÔÏóÀï¼ìË÷³öÏÂÒ»¸ö SERIAL
   Öµ£¬È»ºóÔÙÏÔʽ²åÈ롣ʹÓà 4.15.1 ÀïµÄÀý±í£¬¿ÉÓÃαÂëÕâÑùÃèÊö£º
       new_id = execute("SELECT nextval('person_id_seq')");
       execute("INSERT INTO person (id, name) VALUES (new_id, 'Blaise
   Pascal')");
   ÕâÑù»¹ÄÜÔÚÆäËû²éѯÖÐʹÓôæ·ÅÔÚ new_id ÀïµÄÐÂÖµ£¨ÀýÈ磬×÷Ϊ person
   ±íµÄÍâ¼ü£©¡£×¢Òâ×Ô¶¯´´½¨µÄ SEQUENCE ¶ÔÏóµÄÃû³Æ½«»áÊÇ
   <table>_<serialcolumn>_seq£¬ÕâÀï table ºÍ serialcolumn
   ·Ö±ðÊÇÄãµÄ±íµÄÃû³ÆºÍÄãµÄ SERIAL ×ֶεÄÃû³Æ¡£
   ÀàËÆµÄ£¬ÔÚ SERIAL ¶ÔÏóȱʡ²åÈëºóÄã¿ÉÒÔÓú¯Êý currval() ¼ìË÷¸Õ¸³ÖµµÄ
   SERIAL Öµ£¬ÀýÈ磬
       execute("INSERT INTO person (name) VALUES ('Blaise Pascal')");
       new_id = execute("SELECT currval('person_id_seq')");
   ×îºó£¬Äã¿ÉÒÔʹÓÃ´Ó INSERT Óï¾ä·µ»ØµÄ OID
   ²éÕÒȱʡֵ£¬¾¡¹ÜÕâ¿ÉÄÜÊÇ×îȱ·¦ÒÆÖ²ÐԵķ½·¨¡£ÔÚ Perl ÀʹÓôøÓÐ
   Edmund Mergl µÄ DBD::Pg Ä£¿éµÄ DBI£¬oid Öµ¿ÉÒÔͨ¹ý $sth->execute()
   ºóµÄ $sth->{pg_oid_status} »ñµÃ¡£
   
    4.15.3) ʹÓà currval() ºÍ nextval() »áµ¼ÖÂÒ»¸öÓëÆäËûÓû§Ö®¼äµÄÎÉÂÒÇé¿öÂð£¿
    
   ²»»á¡£currval() ·µ»Øºǫ́½ø³Ì¶ø²»ÊÇËùÓÐÓû§¸³ÓèµÄµ±Ç°Öµ¡£
   
    4.15.4)
    Ϊʲô²»ÔÚÊÂÎñÒì³£ÖÐÖ¹ºóÖØÓÃÐòÁкÅÄØ£¿ÎªÊ²Ã´ÔÚÐòÁкÅ×ֶεÄȡֵÖдæÔÚ¼ä¶ÏÄØ£
    ¿
    
   ΪÁËÌá¸ß²¢·¢ÐÔ£¬ÐòÁкÅÔÚÐèÒªµÄʱºò¸³ÓèÕýÔÚÔËÐеÄÊÂÎñ£¬²¢ÇÒÖ»ÔÚÊÂÎñ½áÊø
   ֮ǰ²»·âËø¡£Õâ¾Í»áµ¼ÖÂØ²ÕÛÊÂÎñºóµÄÐòÁкųöÏÖ¼ä¸ô¡£
   
    4.16) ʲôÊÇ OID£¿Ê²Ã´ÊÇ TID£¿
    
   OID ÊÇ PostgreSQL ÖÐÐеÄΨһ±êʶ¡£PostgreSQL
   Àï´´½¨µÄÿһÐж¼»ñµÃÒ»¸öΨһµÄ OID¡£ËùÓÐÔÚ initdb ¹ý³ÌÖд´½¨µÄ OID
   ¶¼Ð¡ÓÚ 16384 £¨²Î¼û include/access/transam.h£©¡£ËùÓÐÓû§´´½¨µÄ OID
   ¶¼´óÓÚ»òµÈÓÚÕâ¸öÖµ¡£È±Ê¡Ê±£¬ËùÓÐÕâЩ OID
   ²»½öÔÚÒ»¸ö±í»òÒ»¸öÊý¾Ý¿âÀïÃæÎ¨Ò»£¬¶øÇÒÔÚÕû¸ö PostgreSQL
   °²×°ÀïÒ²ÊÇΨһµÄ¡£
   PostgreSQL ÔÚËüµÄÄÚ²¿ÏµÍ³±íÀïʹÓà OID ÔÚ±íÖ®¼ä½¨Á¢ÁªÏµ¡£ÕâЩ OID
   ¿ÉÒÔÓÃÓÚ±êÊ¶ÌØ¶¨µÄÓû§ÐÐÒÔ¼°ÓÃÔÚÁ¬½ÓÀï¡£½¨ÒéʹÓÃ×Ö¶ÎÀàÐÍ OID ´æ´¢ OID
   Öµ¡£¿ÉÒÔÔÚ OID ×Ö¶ÎÉÏ´´½¨Ò»¸öË÷ÒýÒÔ¿ìËÙ·ÃÎÊ¡£
   OID ´ÓÒ»¸ö±»ËùÓÐÊý¾Ý¿âʹÓõÄÖÐÐÄÇøÓòÀ︳ֵ¸øËùÓÐÐÂÐС£Èç¹ûÄãÏë°Ñ OID
   ¸Ä³É±ðµÄÖµ£¬»òÕßÏë×öÒ»·Ý±íµÄ´øÔʼ OID µÄ¿½±´£¬Äã¿ÉÒÔ×öµ½£º
       CREATE TABLE new(old_oid oid, mycol int);
       SELECT old_oid, mycol INTO new FROM old;
       COPY new TO '/tmp/pgtable';
       DELETE FROM new;
       COPY new WITH OIDS FROM '/tmp/pgtable';
   OID
   ÓÃ4×Ö½ÚµÄÕûÊý±£´æ£¬ÔÚ³¬¹ý40ÒÚʱ½«Òç³ö¡£Ã»ÓÐÈ˱¨¸æ³öÏÖ¹ýÒç³ö£¬¶øÎÒÃÇ´òË
   ãÔÚÓÐÈ˱¨¸æÖ®Ç°Ïû³ýÕâ¸öÏÞÖÆ¡£
   TID ÓÃÓÚ±êʶ´ø×ÅÊý¾Ý¿é£¨µØÖ·£©ºÍ£¨¿éÄÚ£©Æ«ÒƵÄÌØ¶¨µÄÎïÀíÐС£TID
   ÔÚÐб»¸ü¸Ä»òÖØÔØºó·¢Éú¸Ä±ä¡£Ë÷ÒýÈë¿ÚʹÓÃËüÃÇÖ¸ÏòÎïÀíÐС£
   
    4.17) PostgreSQL ʹÓõÄһЩÊõÓïµÄº¬ÒåÊÇʲô£¿
    
   һЩԴ´úÂëºÍһЩ¾ÉÒ»µãµÄÎĵµÊ¹ÓÃһЩÓиü³£ÓÃÓ÷¨µÄÊõÓï¡£ÏÂÃæÊÇÆäÖÐÒ»²¿
   ·Ö£º
       table, relation, class
       row, record, tuple
       column, field, attribute
       retrieve, select
       replace, update
       append, insert
       OID, serial value
       portal, cursor
       range variable, table name, table alias
   ÓÐÒ»¸öͨÓÃÊý¾Ý¿âÊõÓïµÄÁÐ±í£ºhttp://hea-www.harvard.edu/MST/simul/softw
   are/docs/pkgs/pgsql/glossary/glossary.html ¡£
   
    4.18) ΪʲôÎÒÊÕµ½´íÎó¡°ERROR: Memory exhausted in AllocSetAlloc()¡±£¿
    
   ÕâºÜ¿ÉÄÜÊÇϵͳµÄÐéÄâÄÚ´æÓùâÁË£¬»òÕßÄں˶ÔijЩ×ÊÔ´Óнϵ͵ÄÏÞÖÆÖµ¡£ÔÚÆô
   ¶¯ postmaster ֮ǰÊÔÊÔÏÂÃæµÄÃüÁ
       ulimit -d 262144
       limit datasize 256m
   È¡¾öÓÚÄãÓõÄ
   shell£¬ÉÏÃæÃüÁîÖ»ÓÐÒ»ÌõÄܳɹ¦£¬µ«ÊÇËü½«°ÑÄãµÄ½ø³ÌÊý¾Ý¶ÎÏÞÖÆÉèµÃ±È½Ï¸ß£
   ¬Òò¶øÒ²ÐíÄÜÈòéѯÍê³É¡£ÕâÌõÃüÁîÓ¦ÓÃÓÚµ±Ç°½ø³Ì£¬ÒÔ¼°ËùÓÐÔÚÕâÌõÃüÁîÔËÐк
   ó´´½¨µÄ×Ó½ø³Ì¡£Èç¹ûÄãÊÇÔÚÔËÐÐSQL¿Í»§¶ËʱÒòΪºǫ́·µ»ØÁËÌ«¶àµÄÊý¾Ý¶ø³öÏÖ
   ÎÊÌ⣬ÇëÔÚÔËÐпͻ§¶Ë֮ǰִÐÐÉÏÊöÃüÁî¡£
   
    4.19) ÎÒÈçºÎ²ÅÄÜÖªµÀËùÔËÐÐµÄ PostgreSQL µÄ°æ±¾£¿
    
   ´Ó psql À¼üÈë SELECT version()£»
   
    4.20) ΪʲôÎҵĴó¶ÔÏó²Ù×÷µ¼Ö´íÎó¡°invalid large obj
    descriptor¡±£¨·Ç·¨µÄ´ó¶ÔÏóÃèÊö·û£©£¿
    
   ÄãÐèÒªÔÚʹÓÃÈκδó¶ÔÏó¾ä±úµÄǰºó·ÅÉÏ BEGIN WORK ºÍ
   COMMIT£¬Ò²¾ÍÊÇ˵£¬°üΧ lo_open ... lo_close¡£
   Ŀǰ PostgreSQL
   Ç¿ÖÆÊµÊ©ÕâÌõ¹æÔò£ºÔÚÊÂÎñÌύʱ¹Ø±Õ´ó¶ÔÏó¾ä±ú£¬ÕâÑù£¬£¨Ã»ÓвÉÓÃÊÂÎñʱ£©
   £¬Ê״ζԴó¶ÔÏó¾ä±ú×öÈκÎÊÂÇéµÄÆóͼ¶¼»áµ¼ÖÂÒ»¸ö invalid large obj
   descriptor¡£ËùÒÔ£¬Èç¹ûÄãûÓÐʹÓÃÒ»¸öÊÂÎñ£¬ÒÔǰÄܹ¤×÷µÄ´úÂ루ÖÁÉÙÊÇ´ó¶à
   Êýʱ¼ä£©½«»áÉú³ÉÕâôһ¸ö´íÎóÐÅÏ¢¡£
   Èç¹ûÄãʹÓÿͻ§¶Ë½Ó¿Ú£¬Èç ODBC£¬Äã¿ÉÄÜÐèÒª set auto-commit off¡£
   
    4.21) ÎÒÈçºÎ´´½¨Ò»¸öȱʡֵÊǵ±Ç°Ê±¼äµÄ×ֶΣ¿
    
   ʹÓà CURRENT_TIMESTAMP£º
       CREATE TABLE test(x int, modtime timestamp DEFAULT
   CURRENT_TIMESTAMP);
   
    4.22) ΪʲôʹÓà IN µÄ×Ó²éѯÕâôÂý£¿
    
   Ŀǰ£¬ÎÒÃÇͨ¹ýΪÍâ²éѯµÄÿһÐÐ˳ÐòɨÃè×Ó²éѯµÄ½á¹ûÀ´Á¬½Ó×Ó²éѯºÍÍâ²éѯ
   ¡£Èç¹û×Ó²éѯ·µ»ØÉÙÊý¼¸ÐУ¬¶øÍâ²éѯ·µ»ØºÜ¶àÐУ¬IN
   Ö´Ðеúܿ졣ΪÁ˼ӿìÆäËû IN ²éѯµÄÖ´ÐУ¬¿ÉÒÔÓà EXISTS Ìæ»» IN£º
       SELECT *
       FROM tab
       WHERE col IN (SELECT subcol FROM subtab);
   ¸ÄΪ£º
       SELECT *
       FROM tab
       WHERE EXISTS (SELECT subcol FROM subtab WHERE subcol = col);
   ºóÕßÒªÏëÖ´Ðеøü¿ì£¬subcol
   Ó¦¸ÃÊÇÒ»¸öË÷ÒýÁС£ÎÒÃÇÏ£ÍûÔÚδÀ´µÄ·¢²¼°æ±¾ÖÐÐÞ²¹Õâ¸öÏÞÖÆ¡£
   
    4.23) ÎÒÔõÑù½øÐÐ outer join £¨ÍâÁ¬½Ó£©£¿
    
   PostgreSQL ²ÉÓñê×¼µÄ SQL Óï·¨Ö§³ÖÍâÁ¬½Ó¡£ÕâÀïÊÇÁ½¸öÀý×Ó£º
       SELECT *
       FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
   »ò
       SELECT *
       FROM t1 LEFT OUTER JOIN t2 USING (col);
   ÕâÁ½¸öµÈ¼ÛµÄ²éѯÔÚ t1.col ºÍ t2.col ÉÏ×öÁ¬½Ó£¬²¢ÇÒ·µâ»?t1
   ÖÐËùÓÐδÁ¬½ÓµÄÐУ¨ÄÇЩÔÚ t2 ÖÐûÓÐÆ¥ÅäµÄÐУ©¡£ÓÒ[Íâ]Á¬½Ó(RIGHT OUTER
   JOIN)½«·µ»Ø t2 ÖÐδÁ¬½ÓµÄÐС£ÍêÈ«ÍâÁ¬½Ó£¨FULL OUTER JOIN£©½«·µ»Ø t1 ºÍ
   t2 ÖÐδÁ¬½ÓµÄÐС£¹Ø¼ü×Ö OUTER
   ÔÚ×ó[Íâ]Á¬½Ó¡¢ÓÒ[Íâ]Á¬½ÓºÍÍêÈ«[Íâ]Á¬½ÓÖÐÊÇ¿ÉÑ¡µÄ£¬ÆÕͨÁ¬½Ó±»³ÉΪÄÚÁ¬½Ó
   £¨INNER JOIN£©¡£
   ÔÚ´ËǰµÄ°æ±¾ÖУ¬ÍâÁ¬½Ó¿ÉÒÔÓà UNION ºÍ NOT IN
   À´Ä£Äâ¡£ÀýÈ磬ÏÂÃæµÄÀý×ÓÔÚ±í tab1 ºÍ tab2 Ö®¼ä×öÍâÁ¬½Ó£º
       SELECT tab1.col1, tab2.col2
       FROM tab1, tab2
       WHERE tab1.col1 = tab2.col1
       UNION ALL
       SELECT tab1.col1, NULL
       FROM tab1
       WHERE tab1.col1 NOT IN (SELECT tab2.col1 FROM tab2)
       ORDER BY col1
   
    4.24) ÈçºÎʹÓÃÉæ¼°¶à¸öÊý¾Ý¿âµÄ²éѯ£¿
    
   ûÓа취²éѯµ±Ç°Êý¾Ý¿âÖ®ÍâµÄÊý¾Ý¿â¡£ÒòΪ PostgreSQL
   ¼ÓÔØÊý¾Ý¿âÏà¹ØµÄϵͳĿ¼£¨ÏµÍ³±í£©£¬¿çÊý¾Ý¿âµÄ²éѯÈçºÎÖ´ÐÐҲδÃ÷È·¡£
   contrib/dblink
   ÔÊÐí²ÉÓú¯Êýµ÷ÓÃʵÏÖ¿ç¿â²éѯ¡£µ±È»¿ÉÒÔͬʱÁ¬½Óµ½²»Í¬µÄÊý¾Ý¿â²¢ÔÚ¿Í»§¶Ë
   ºÏ²¢½á¹û¡£
   
    4.25) ÈçºÎÈú¯Êý·µ»Ø¶àÐлò¶àÁУ¿
    
   ¿ÉÒÔÔÚ PL/pgSQL º¯ÊýÖÐʹÓà refcursors ·µ»Ø½á¹û¼¯¡£²Î¿´
   http://www.PostgreSQL.org/idocs/index.php?plpgsql-cursors.html,
   23.7.3.3½Ú¡£
   
    4.26) ΪʲôÔÚ PL/PgSQL º¯ÊýÖв»Äܿɿ¿µØ´´½¨»òɾ³ýÁÙʱ±í£¿
    
   PL/PgSQL »º´æº¯ÊýµÄÄÚÈÝ£¬ÓÉ´Ë´øÀ´µÄÒ»¸ö²»ºÃµÄ¸±×÷ÓÃÊÇÈôÒ»¸ö PL/PgSQL
   º¯Êý·ÃÎÊÁËÒ»¸öÁÙʱ±í£¬È»ºó¸Ã±í±»É¾³ý²¢Öؽ¨ÁË£¬ÔòÔٴε÷Óøú¯Êý½«Ê§°Ü£¬
   ÒòΪ»º´æµÄº¯ÊýÄÚÈÝÈÔȻָÏò¾ÉµÄÁÙʱ±í¡£½â¾öµÄ·½·¨ÊÇÔÚ PL/PgSQL ÖÐÓÃ
   EXECUTE ¶ÔÁÙʱ±í½øÐзÃÎÊ¡£ÕâÑù»á±£Ö¤²éѯÔÚÖ´ÐÐǰ×ÜÊÇÖØÐ·ÖÎö¡£
   
    4.27) ÓÐÄÄЩÊý¾Ý¸´ÖÆÑ¡Ï
    
   Óм¸ÖÖÖ÷/´Ó·½Ê½µÄ¸´ÖÆÑ¡Ïî¡£ÕâЩѡÏîÖ»ÔÊÐíÖ÷Êý¾Ý¿â½øÐиüУ¬´ÓÊý¾Ý¿âÖ»Ä
   ܽøÐжÁ¡£ÍøÒ³
   http://gborg.PostgreSQL.org/genpage?replication_research
   µÄ×îºóÁгöÁËÕâЩѡÏî¡£ÔÚ
   http://gborg.PostgreSQL.org/project/pgreplication/projdisplay.php
   ÕýÔÚ½øÐÐÒ»¸ö¶àÖ÷±¾¸´ÖƵĽâ¾ö·½°¸¡£
   
    4.28) ÓÐÄÄЩÊý¾Ý¼ÓÃÜÑ¡Ï
    
   contrib/pgcrypto °üº¬Á˺ܶàÔÚ SQL
   ²éѯÖÐʹÓõļÓÃܺ¯Êý¡£¼ÓÃܿͻ§¶Ëµ½·þÎñÆ÷¶Ë´«ÊäÊý¾ÝµÄΨһ·½·¨ÊÇÔÚ
   pg_hba.conf ÖвÉÓà hostss ¡£
   7.3 °æ±¾ÖÐ×Ô¶¯¶ÔÊý¾Ý¿âÓû§ÃÜÂë½øÐмÓÃÜ¡£ÔÚÒÔǰµÄ°æ±¾ÖУ¬±ØÐëÔÚ
   postgresql.conf Öдò¿ª PASSWORD_ENCRYPTION
   Ñ¡Ïî¡£·þÎñÆ÷¿ÉÒÔÔËÐÐÔÚ¼ÓÃܵÄÎļþϵͳÉÏ£¨ÒÔ´ïµ½¼ÓÃܵÄÄ¿µÄ£©¡£
   ----------------------------------------------------------------------
   ----------
   
                              À©Õ¹ PostgreSQL
                                      
    5.1) ÎÒдÁËÒ»¸öÓû§¶¨Ò庯Êý¡£µ±ÎÒÔÚ psql ÀïÔËÐÐʱ£¬ÎªÊ²Ã´»áµ¼Ö core dump£¿
    
   ²úÉúÕâ¸öÎÊÌâµÄÔÒòºÜ¶à¡£ÇëÏÈÔÚÒ»¸öµ¥¶ÀµÄ²âÊÔ³ÌÐòÖвâÊÔÄãµÄ×Ô¶¨Ò庯Êý¡£
   
    5.2) ÎÒÈçºÎÄܸø PostgreSQL ¹±Ï×һЩͦ²»´íµÄÐÂÀàÐͺͺ¯Êý£¿
    
   ½«ÄãµÄÀ©Õ¹·¢Ë͵½ pgsql-hackers ÓʼþÁÐ±í£¬ËüÃÇ×îÖջᱻ·Åµ½ contrib/
   ×ÓĿ¼¡£
   
    5.3) ÎÒÔõÑùдһ¸ö·µ»ØÒ»ÌõÔª×éµÄ C º¯Êý£¿
    
   ÔÚ PostgreSQL 7.3 ÒÔºóµÄ°æ±¾ÖУ¬C, PL/PgSQL ºÍ SQL
   Íêȫ֧³Ö·µ»ØÖµÎª±íµÄº¯Êý¡£¸ü¶àÐÅÏ¢Çë²Î¿¼ ³ÌÐòÔ±Ö¸ÄÏ£¨the Programmer's
   Guide£©¡£ÔÚ contrib/tablefunc ÖÐÓÐÒ»¸öÀý×ÓÊÇÓà C
   дµÄ·µ»ØÖµÎª±íµÄº¯Êý¡£
   
    5.4) ÎÒÐÞ¸ÄÁËÒ»¸öÔ´Îļþ£¬ÎªÊ²Ã´ÖØÐ±àÒëºóûÓп´µ½¸Ä±ä£¿
    
   Makefiles ÖÐûÓаüº¬Í·ÎļþµÄÕýÈ·ÒÀÀµ¡£Äú±ØÐëÏÈ×ömake clean£¬ ÔÙ×öÒ»´Î
   make ¡£Èç¹ûÄúʹÓõÄÊÇ GCC £¬Ôò¿ÉÒÔ²ÉÓÃÑ¡Ïî --enable-depend
   ÈñàÒëÆ÷×Ô¶¯Éú³ÉÍ·ÎļþµÄÒÀÀµ¹ØÏµ¡£