Re: ITL waits in the dictionary

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Thu, 21 Nov 2019 21:10:07 +0000
Message-ID: <CWXP265MB1750BE49970C2A2CFD6F6F28A54E0_at_CWXP265MB1750.GBRP265.PROD.OUTLOOK.COM>


And seg$ could run into problems if your system has run into the issue of having undo segments with very large numbers of small (64KB extents) which get release or acquired in extreme bursts from concurrent processes occsionally.

Regards
Jonathan Lewis



From: oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org> on behalf of Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> Sent: 21 November 2019 21:06
To: oracle-l_at_freelists.org
Subject: Re: ITL waits in the dictionary

Trying to come up with some reason why ind$ might be subject to ordinary ITL waits - if you're gathering stats use a level of concurrency greater than one the ind$ could be subject to N concurrent processes updating it.

Regards
Jonathan Lewis



From: oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org> on behalf of Mladen Gogala <gogala.mladen_at_gmail.com> Sent: 20 November 2019 17:46
To: oracle-l_at_freelists.org
Subject: ITL waits in the dictionary

I have a bad habit of checking whether any objects in the database are being used so intensely to cause ITL waits. I do occasionally encounter an object and if it's a user object, I can usually fix it. However, here is something that I'm stuck with:

SQL> select owner,object_name,object_type,value from v$segment_Statistics where statistic_name like 'ITL%' and value>0; OWNER OBJECT_NAME OBJECT_TYPE VALUE ________ ______________ ______________ ________

SYS      IND$           TABLE              1049
SYS      SEG$           TABLE                69
SYS      CDEF$          TABLE                22
SYS      I_OBJ2         INDEX                 1
SYS      I_OBJ5         INDEX                 1
SYS      I_COL1         INDEX                 4


6 rows selected.

My pain is obviously with the SYS.IND$ table, which doesn't contain anything of importance, only the definitions of all the indexes in the database. I should have changed SQL.BSQ but that water is now under the bridge. Is there anything else I can do to increase INITRANS for SYS.IND$? The advice like "tell your users not to create indexes" is obviously impossible to follow.
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http://www.freelists.org/webpage/oracle-l Received on Thu Nov 21 2019 - 22:10:07 CET

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