SHOW TABLE STATUS FROM XXX_DB LIKE 'XXX_TABLE'

SHOW TABLE STATUS FROM XXX_DB LIKE 'XXX_TABLE'

Postby CarstenHarnisch » Wed 17 May 2006 08:40

We are in process to the final performance optimization a .NET project using the MySQLDirect.NET provider.

Most data retrieval is done with typed datasets and the "basic" table-mappings. We are using basically InnoDB on most tables, besides a couple of memory and temporary tables.

Anway scanning the mysql.log it results that after firing the "real" sql statement there is always a prepended with a statement like
"SHOW TABLE STATUS FROM xxx_DB LIKE 'xxx_tablename'" !

Anyway this is done for normal select, but also to selects on views and derivated "tables" within complex statements.

For what is this statement needed for? Anyway to get rid of it ? Anyway we are seeing sometime a big performance impact especially in high load situation where the stats are changing very frequently ...

regards

Carsten Harnisch
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Postby Alexey » Wed 17 May 2006 11:23

It has an attitude only toward autoincrement columns.
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Postby CarstenHarnisch » Wed 17 May 2006 17:27

sorry, but this means what ?
This is basically after ALL select statements so I am not sure why this should be related autoincrements ?!?

Carsten
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Postby Alexey » Thu 18 May 2006 06:44

We are checking this carefully. You will be notified as soon as possible.
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Postby Andreas Oesterhelt » Fri 19 May 2006 10:43

Alexey, if this would be of any help, we could send you query log
excerpts that show which queries we use. But it breaks down to
what Carsten already said: Basically every query is followed by
a show table status request. If you need samples from the
application code to look into it, we'd gladly provide them, too.

I know that flagging support requests as "urgent" rarely helps,
but we're in a big hurry regarding this project. Any fast hint would
be greatly appreciated.
Andreas Oesterhelt
 

Postby Alexey » Fri 19 May 2006 11:00

Send us everything you suppose may be helpful.
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Postby Alexey » Wed 04 Oct 2006 13:14

We have checked this.
"SHOW TABLE STATUS" is invoked only for those tables that have autoincremented fields.
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