db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mike Matrigali <mikem_...@sbcglobal.net>
Subject Re: Modified UTF-8 or UTF-16 for temporary Clobs?
Date Wed, 23 May 2007 16:35:10 GMT

Oystein Grovlen - Sun Norway wrote:
> Mike Matrigali wrote:
>  > What is the expected usage pattern for an update on a clob that uses
>> these "temporary" clobs?  What is the usual input format, what is the
>> usual output format?  Do you expect more than one update usually?  Does
>> an update have to rewrite the end of the file on and shrink or expand of
>> a middle of the clob?
> In client/server, a single update may cause a sequence of updates 
> against the embedded driver.  This is because the locator implementation 
>  uses a stored procedure to perform the update, and Derby does not 
> support Clob as procedure parameters.  To overcome that, the Blob is 
> split into segments of max size for VARCHAR.  Hence, it is important at 
> the overhead of positioning is not big in these cases.  One way to 
> optimize for this would be to remember the end position from last write.
How do these calls relate to calls to the store code for the update?  Is
there still one call to store or one per segment?

View raw message