count(*),count(1)和count(主键) 区别

 1 SQL> select count(*) from ysgl_compile_reqsub;
 2 
 3   COUNT(*)
 4 ----------
 5    5288265
 6 
 7 已用时间:  00: 00: 07.51
 8 SQL> select count(1) from ysgl_compile_reqsub;
 9 
10   COUNT(1)
11 ----------
12    5288265
13 
14 已用时间:  00: 00: 00.68
15 SQL> select count(id) from ysgl_compile_reqsub;
16 
17  COUNT(ID)
18 ----------
19    5288265
20 
21 已用时间:  00: 00: 00.68
22 SQL> select count(rowid) from ysgl_compile_reqsub;
23 
24 COUNT(ROWID)
25 ------------
26      5288265
27 
28 已用时间:  00: 00: 01.01
29 SQL> select count(rowid) from ysgl_vdata_his;
30 
31 COUNT(ROWID)
32 ------------
33      5299458
34 
35 已用时间:  00: 00: 09.98
36 SQL> select count(*) from ysgl_vdata_his;
37 
38   COUNT(*)
39 ----------
40    5299458
41 
42 已用时间:  00: 00: 00.93
43 SQL> select count(1) from ysgl_vdata_his;
44 
45   COUNT(1)
46 ----------
47    5299458
48 
49 已用时间:  00: 00: 00.71
50 SQL> select count(1) from ysgl_excelbasic;
51 
52   COUNT(1)
53 ----------
54    3755052
55 
56 已用时间:  00: 00: 04.60
57 SQL> select count(*) from ysgl_excelbasic;
58 
59   COUNT(*)
60 ----------
61    3755052
62 
63 已用时间:  00: 00: 00.50
64 SQL>