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From:Michael Widenius Date:June 20 2001 2:40pm
Subject:Re: Back again to MERGEs...
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Hi!

>>>>> "Paul" == Paul Cadach <paul@stripped> writes:

<cut>
>> 
>> Can't you for now do:
>> 
>> ALTER TABLE merge_table UNION=(empty_copy_of_table);

Paul> What did you mean saying "empty_copy_of_table"? Does I needs to create
Paul> temporary empty table and include it into merge?

Yes.  You can of course also refer to a non existing table, but in
this case everyone that tries to access the table during the rename
will get a table-not-found error.

>> RENAME ...
>> 
>> ALTER TABLE merge_table UNION=(old-union)

Paul> Nice idea but it's not fault-safe (because client/network can crash
Paul> somewhere between ALTER, RENAME and second ALTER, and we will have incorrect
Paul> datas).
Paul> Also, I can't issue 'ALTER TABLE' because all members of MERGE are
Paul> compressed (equal to read-only), and MERGE itself looks like read-only. :(

This should already be fixed in the 4.0 tree.

>> We will look in 4.0 to see what we can do to handle MERGE tables
>> better in this case.

Paul> As I said before, tracking renaming members of MERGE and keep MERGE
Paul> specification intact IMHO would helpful in this situation.

I agree.

Regards,
Monty
Thread
Back again to MERGEs...Michael Widenius20 Jun
Re: Back again to MERGEs...Paul Cadach20 Jun
  • Re: Back again to MERGEs...Michael Widenius20 Jun