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From Mike Matrigali <mikem_...@sbcglobal.net>
Subject Re: upgrade and compiled statements in SYSSTATEMENTS - question
Date Sun, 29 Apr 2007 15:53:50 GMT

Knut.Hatlen@Sun.COM wrote:
> Mike Matrigali <mikem_app@sbcglobal.net> writes:
>>My assumption for both soft and hard upgrade on changes to
>>objects in compiled parts of queries was that I did not have
>>to worry about upgrade.  That any change to query plan data
>>structures stored on disk would be taken care of automatically
>>by just dropping them on any release number change.
>>Is that valid?
> If you by "any release number change" mean change of major or minor
> release number, yes. On soft upgrade, the queries will be read directly
> from org/apache/derby/impl/jdbc/metadata.properties or
> org/apache/derby/impl/sql/catalog/metadata_net.properties. On hard
> upgrade, the statements in SYSSTATEMENTS will be dropped, re-read from
> metadata(_net).properties and recompiled.
> There are some more details on the wiki:
> http://wiki.apache.org/db-derby/MetadataUpgrade

Thanks for the pointer.  From the wiki it seems like we don't drop
SYSSTATEMENTS for soft upgrade.  It also sounds like we prevent reads
from SYSSTATEMENTS for soft upgrade.  Is there meant to be something
preventing writes to SYSSTATEMENTS for soft upgrade (ie. is there
anything preventing recompile from updating SYSSTATEMENTS)?


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