Just think, Nirvana is only one bullet away! > -----Original Message----- > From: Mladen Gogala [mailto:[EMAIL PROTECTED] > Sent: Tuesday, August 05, 2003 11:49 AM > To: Multiple recipients of list ORACLE-L > Subject: RE: 9i - Dynamic SGA - SGA_MAX_SIZE > > > To continue down the Stephen's path, "shutdown abort" will > complete very > quickly > and will drastically decrease the size of SGA. What is more, > the "very busy > environment" > Will not be very busy any more. Perhaps very loud, but not very busy. > > -- > Mladen Gogala > Oracle DBA > > > > -----Original Message----- > Kirtikumar Deshpande > Sent: Tuesday, August 05, 2003 12:35 PM > To: Multiple recipients of list ORACLE-L > > > U R Welcome. > Although, reducing SGA size is technically possible, it can be a very > expensive operation in a busy environemt and can take a long time to > complete. I have not run any specific tests to see how long > it takes to > reduce SGA by a certain amount, but you can imagine what must > be done (find > least used blocks/age out blocks, keep them from re-use, and finally > 'detach' them etc..) > > - Kirti > > --- Mohammed Shakir <[EMAIL PROTECTED]> wrote: > > Kirti > > > > Thanks for the info. > > > > I could not raise dynamically the size of db_cache_size and did not > > know why, until I noticed the new parameter sga_max_size. Anyway, I > > tried to lower the size of db_cache_size dynamically and I did not > > have a problem. So sgma_max_size does play its role in > > db_cache_sizing. > > > > I have not tested where I increase the size of sga_max_size using > > init.ora and then try to increase the size of db_cache_size > > dynamically by the same size as the increase in > sga_max_size. That is > > the test for coming weekend. > > > > > > --- Kirtikumar Deshpande <[EMAIL PROTECTED]> wrote: > > > SGA_MAX_SIZE was introduced in 9i to allow dynamic sizing of SGA > > > (Dynamic Sizing feature) components such as, shared pool, large > > > pool, buffer cache etc. In versions up to 8i, such changes > > > required bouncing the instance. > > > This parameter assumes the value of the SGA at instance startup. > > > Various components of the SGA can > > > then be increased/reduced as and when needed. The total SGA, thus, > > > can reach a maximum value set > > > by SGA_MAX_SIZE (if set in the init.ora file). That's the idea. > > > However, the implementation is > > > different on various platforms. With ISM, and DISM, on > Solaris, there > > > are other issues when it > > > comes to using Dynamic SGA. You may want to search Metalink for > > > specific notes/articles for > > > Solaris. > > > On AIX 5L as I found out, Oracle uses SGA_MAX_SIZE, if set in > > > init.ora, at the instanace startup, > > > and allocates the excess (difference in computed SGA value and set > > > SGA_MAX_SIZE) to 'variable > > > size'. Hence there is no room for any dynamic sizing > (upward) of any > > > SGA component. I did not try > > > to downsize shared pool first, and 'upsize' buffer cache > later. May > > > be that would work, but that > > > is not the intention of using this parameter. > > > > > > PGA_AGRREGATE_TARGET is completely different from this > parameter. It > > > sets an instance-wide upper limit for the memory used by sorting, > > > hashing processes. > > > > > > Hope this helps.. > > > > > > - Kirti > > > > > > > > __________________________________ > Do you Yahoo!? > Yahoo! SiteBuilder - Free, easy-to-use web site design software > http://sitebuilder.yahoo.com > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Kirtikumar Deshpande > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') > and in the > message BODY, include a line containing: UNSUB ORACLE-L (or > the name of > mailing list you want to be removed from). You may also send the HELP > command for other information (like subscribing). > > > -------------------------------------------------------- > Note: > This message is for the named person's use only. It may > contain confidential, proprietary or legally privileged > information. No confidentiality or privilege is waived > or lost by any mistransmission. If you receive this > message in error, please immediately delete it and all > copies of it from your system, destroy any hard copies > of it and notify the sender. You must not, directly or > indirectly, use, disclose, distribute, print, or copy > any part of this message if you are not the intended > recipient. Wang Trading LLC and any of its subsidiaries > each reserve the right to monitor all e-mail > communications through its networks. > > Any views expressed in this message are those of the > individual sender, except where the message states > otherwise and the sender is authorized to state them > to be the views of any such entity. > --------------------------------------------------------- > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Mladen Gogala > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Stephen Lee INET: [EMAIL PROTECTED]
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