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Posted to derby-user@db.apache.org by Alan Burlison <Al...@sun.com> on 2009/06/18 11:56:06 UTC
SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE versus SYSCS_UTIL.SYSCS_UPDATE_STATISTICS
Does SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE recalculate statistics, or
is it necessary to do a SYSCS_UTIL.SYSCS_UPDATE_STATISTICS as well? The
docs are unclear.
--
Alan Burlison
--
Re: SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE versus SYSCS_UTIL.SYSCS_UPDATE_STATISTICS
Posted by Alan Burlison <Al...@sun.com>.
Knut Anders Hatlen wrote:
> Could you please file a JIRA issue and point to the
> sections that you found unclear? Thanks.
https://issues.apache.org/jira/browse/DERBY-4289
--
Alan Burlison
--
Re: SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE versus SYSCS_UTIL.SYSCS_UPDATE_STATISTICS
Posted by Alan Burlison <Al...@sun.com>.
Knut Anders Hatlen wrote:
> As far as I can see, SYSCS_INPLACE_COMPRESS_TABLE does not update the
> index statistics. I couldn't find anything in the in-place compress code
> that attempted to update the statistics, and it didn't appear to have
> updated them when I monitored the CREATIONTIMESTAMP column in
> SYS.SYSSTATISTICS.
>
> I think much of the documentation about index statistics was written
> before in-place compress was implemented, which is probably why the docs
> are unclear. Could you please file a JIRA issue and point to the
> sections that you found unclear? Thanks.
Hmm just noticed this in the docs for the related
SYSCS_UTIL.SYSCS_COMPRESS_TABLE procedure:
"The SYSCS_UTIL.SYSCS_COMPRESS_TABLE system procedure updates statistics
on all indexes as part of the index rebuilding process."
But no mention of that (either way) for
SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE
--
Alan Burlison
--
Re: SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE versus
SYSCS_UTIL.SYSCS_UPDATE_STATISTICS
Posted by Knut Anders Hatlen <Kn...@Sun.COM>.
Alan Burlison <Al...@Sun.COM> writes:
> Does SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE recalculate statistics,
> or is it necessary to do a SYSCS_UTIL.SYSCS_UPDATE_STATISTICS as well?
> The docs are unclear.
Hi Alan,
As far as I can see, SYSCS_INPLACE_COMPRESS_TABLE does not update the
index statistics. I couldn't find anything in the in-place compress code
that attempted to update the statistics, and it didn't appear to have
updated them when I monitored the CREATIONTIMESTAMP column in
SYS.SYSSTATISTICS.
I think much of the documentation about index statistics was written
before in-place compress was implemented, which is probably why the docs
are unclear. Could you please file a JIRA issue and point to the
sections that you found unclear? Thanks.
--
Knut Anders