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From Rick Hillegas <Richard.Hille...@Sun.COM>
Subject Re: btree overflow during insert
Date Thu, 13 Nov 2008 16:58:19 GMT
Hi Alan,

Do you really need a 4KB key? That seems like a very big key. Is there 
some reduction, summary, or checksum of the text which might serve as a 
more compact key?


Alan Burlison wrote:
> Knut Anders Hatlen wrote:
>> I have logged DERBY-3947 and attached a reproducible test case.
>> Note that it is possible to set derby.storage.pageSize just for a single
>> index by issuing
>> CALL SYSCS_UTIL.SET_DATABASE_PROPERTY('derby.storage.pageSize', '32768')
>> right before the index in question is created and resetting it with
>> CALL SYSCS_UTIL.SET_DATABASE_PROPERTY('derby.storage.pageSize', null)
>> afterwards.
> Thank-you very much for doing this, and the comments in the bug are 
> useful too as they gives me a hint as to how we might change the table 
> definition to avoid the problem altogether.  We can probably work 
> around this by reducing the length of the varchar column being 
> indexed, which is a little aggressively-sized (32672).  Failing that 
> we can use the workaround you suggest.
> One thing I'm not quite clear on: does Derby allocate the full length 
> of a varchar column in an index that uses it?  In our case, although 
> the column is varchar(32672), only a small fraction of it is used, 4Kb 
> at most.

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