Re: MySQL 3.23.44 not using indexes

[Myk Melez]

Michael Widenius wrote:

>You can check if the index are ok with CHECK TABLE;  If this says the
>index is ok, they are not corrupted.
>
Apparently this doesn't work in all cases.  "CHECK TABLE" told me 
everything was fine, but dumping the data to a dump file via mysqldump 
and then re-importing it into a new database fixed the problem, so there 
must have been some undetected corruption in the database.

>The above shows that MySQL could use the index but decides to not use
>this because it concludes that a table scan will be faster.
>
>To verify this can you send us the result for the following queries:
>
>SELECT count(*) FROM bugs WHERE bug_status IN ('NEW', 'ASSIGNED', 'REOPENED');
>SELECT count(*) FROM bugs;
>
The results were about 25,000 and 131,000, respectively.

-myk