Optimising

[Sephiriz]

Occasionally, when I optimize a table, I cannot even access the table anymore, and I need to delete it, because it doesn\'t work. Can someone tell me why this happens?

[shivabharat]

Have you read these

 

OPTIMIZE TABLE should be used if you have deleted a large part of a table or if you have made many changes to a table with variable-length rows (tables that have VARCHAR, BLOB, or TEXT columns).  Deleted records are maintained in a linked list and subsequent INSERT operations reuse old record positions. You can use OPTIMIZE TABLE to reclaim the unused space and to defragment the datafile.

 

OPTIMIZE TABLE works the following way:  

 

·If the table has deleted or split rows, repair the table.

·If the index pages are not sorted, sort them.

·If the statistics are not up to date (and the repair couldn\'t be done by sorting the index), update them.