Question

我遇到了一个奇怪的现象，我希望，有人可以向我解释这个：

我有一些＆＃34;静态＆＃34;桌子（每天更换一次）。

mysql> select 'appObjectGroups' as tbl, count(*) as num from appObjectGroups
  union select 'appObjectDependencies' as tbl, count(*) as num from appObjectDependencies
  union select 'appObjectUrls' as tbl, count(*) as num from appObjectUrls 
  union select 'appObjectValues' as tbl, count(*) as num from appObjectValues 
  union select 'appObjects;' as tbl, count(*) as num from appObjects;
+-------------------------+------+
| tbl                     | num  |
+-------------------------+------+
| appObjectGroups         | 1149 |
| appObjectDependencies   | 6885 |
| appObjectUrls           | 1162 |
| appObjectValues         | 3795 |
| appObjects;             | 5409 |
+-------------------------+------+
5 rows in set (0.00 sec)

mysql> select table_name as tbl, table_rows as num from information_schema.tables where table_schema='mySchema' and table_name like 'app%';
+-------------------------+------+
| tbl                     | num  |
+-------------------------+------+
| appObjectGroups         | 1141 |
| appObjectDependencies   | 6153 |
| appObjectUrls           | 1141 |
| appObjectValues         | 3584 |
| appObjects              | 6061 |
+-------------------------+------+
5 rows in set (0.01 sec)

那么，table_rows如何报告与count(*)不同的内容？

对我来说更重要：哪一个是正确的？： - ）

Answer 1

引自documentation：

对于InnoDB表，行计数只是SQL中使用的粗略估计 优化。（如果对InnoDB表进行分区，也是如此。）

mysql在information_schema中的行数count（*）与table.table_rows不一致

1 个答案: