Why is SHOW COLLATION So Frequently Executed? (Doc ID 1582899.1)

Last updated on MAY 05, 2016

Applies to:

MySQL Server - Version 5.0 and later
Information in this document applies to any platform.

Symptoms

Show collation is executed at very high frequency and leads to "excessive table scans" reported by MySQL Enterprise Monitor.

 show status like '%collation%';
+---------------------+-------+
| Variable_name       | Value |
+---------------------+-------+
| Com_show_collations | 13344 |
+---------------------+-------+
1 row in set (0.10 sec)
show status like '%uptime%';
+---------------------------+--------+
| Variable_name             | Value  |
+---------------------------+--------+
| Uptime                    | 133    |
| Uptime_since_flush_status | 133    |
+---------------------------+--------+
2 rows in set (0.00 sec)

 100 times/s is a bit too much!

Cause

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