Home -> Mailing Lists -> Oracle-L -> Re: query hanged in parsing

Re: query hanged in parsing

From: Jonathan Lewis <jlewisoracle_at_gmail.com>
Date: Thu, 16 May 2024 12:30:45 +0100
Message-ID: <CAGtsp8npAotKqxMinOo=Ysy9xMRWSHdG4iLz2QpLpL3Ysjjj=g_at_mail.gmail.com> 








In more recent versions of Oracle, when you drop a partition from a
partitioned table with global indexes the index entries for that partition
may not be deleted immediately and there is a procedure (which can be
called manually, or could be left to happen in the auto cleanup job) to
delete the entries later.  Such entries are referred to a Orphan entries.



At run time, when using the index, the runtime engine has a note of which
partitions have been dropped and therefore has a note of which index
entries (which include the parittions data object id in their rowid) should
be skipped.



This makes me wonder if the "65K partition" table has a "large" number of
dropped partitions which have deliberately not had their orphan entries
deleted and the parse time may be Oracle trying to work out what the
statistics of index access would be if those index entries were to be
ignored.



Regards


Jonathan Lewis




On Thu, 16 May 2024 at 12:02, Mark W. Farnham <mwf_at_rsiz.com> wrote:



> What do you mean by “orphan entries in indexes?”


>

>

>

> mwf

>

>

>

>

>



--
http://www.freelists.org/webpage/oracle-l


Received on Thu May 16 2024 - 13:30:45 CEST












Original text of this message