[rt-users] RT query for test InnoDB performance

[Francesco Dalla Ca']

Vivek Khera wrote:

>
> On Jan 17, 2006, at 5:39 PM, Ruslan Zakirov wrote:
>
>>> My understanding is that the above ALTER command does the moral
>>> equivalent of a VACUUM FULL in postgres.  ie, it cleans out the dead
>>> tuples and reclaims the unused space from the table.
>>
>> It's not full vacuum, it only rebuilds indexes.
>
>
> You'd think they'd call this command 'REINDEX tablename' instead,  
> then.  But that'd be too obvious :-(

 From mysql support:

 > ALTER recreates the table as if it was DROPped and CREATEd again it
 > updates all index statistics and "defragments" the table.

A "null" ALTER TABLE (ALTER TABLE x_y_z ENGINE=InnoDB;) is a very 
expensive operation... but more effective than a ANALYZE+OPTIMIZE.

Regards, Francesco.

p.s.: Can anyone give me a sample sql query from "Query browser"?

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