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Re: Difference between using Merge vs. symbolic-links approach?
Posted by: M P
Date: June 12, 2007 12:32AM

KimSeong Loh Wrote:
> For 1, I am not aware of this limitation, I have
> to check.

Hi. Quoting from the mySQL documentation page regarding
"You cannot use a number of MyISAM features in MERGE tables. For example, you cannot create FULLTEXT indexes on MERGE tables. (You can, of course, create FULLTEXT indexes on the underlying MyISAM tables, but you cannot search the MERGE table with a full-text search.)."

> For 2, I suspect if you do a simple view like
> select * from anothertable, this should be using
> algorithm should be able to reuse the indexes in
> the underlying table. With TEMPTABLE algorithm the
> indexes of the underlying table is only used to
> generate the view result, cannot be used on the
> actual query, so fulltext index is not usable
> here.
> If you do UNION of multiple tables in the view,
> the algorithm could be TEMPTABLE.
> Anyway, I have not done fulltext in this manner,
> so cannot be sure.

I was actually needing to create a VIEW based on a UNION
of tables, so as you mention the algorithm will be
TEMPTABLE and hence the FULLTEXT index will not be usuable.
Even for a simple "select * from 'tableX'" VIEW using the
MERGE algorithm, wouldn't the documentation reference
quoted above imply that FULLTEXT wouldn't work? (Or,
is "merge" in this context quite different?)

Your answers are quite useful in furthering my understanding,
and are much appreciated.

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