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Re: Ok to write directly to member of merge table?
Posted by: KimSeong Loh
Date: May 05, 2006 02:08AM

Seems like it is possible to create a temporary merge table.

I guess it is probably due to table locking issues.
As the temporary table is connection specific, no locks is necessary.

However, when the temporary table is a MERGE table, then the underlying MyISAM tables need to be locked, but there is a possibility that the temporary MERGE table did not enforce the necessary table locking.

I did a simple test, I locked the underlying MyISAM tables with a write lock from another connection, the temporary Merge table is not locked, but a non-temporary Merge table will be locked. I can continue to insert into the temporary Merge table even though the underlying MyISAM table has been write locked by the other connection. I can see the new rows, but once I unlock the tables from the other connection, the rows inserted was gone.

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