Re: how does oracle store cursors in memory?

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Sat, 14 Feb 2004 09:48:40 -0000
Message-ID: <005c01c3f2df$b9df8c10$6702a8c0@Primary>

Ryan,

If your comment about hash maps relates to hash joins, the datablocks are NOT stored in the PGA, some columns from some of the rows in the 'first' table's data blocks are copied into the PGA.

Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

  The educated person is not the person
  who can answer the questions, but the
  person who can question the answers -- T. Schick Jr

Next public appearances:
March 2004 Hotsos Symposium - The Burden of Proof March 2004 Charlotte NC OUG - CBO Tutorial April 2004 Iceland

One-day tutorials:
http://www.jlcomp.demon.co.uk/tutorial.html

Three-day seminar:
see http://www.jlcomp.demon.co.uk/seminar.html
____UK___February
____UK___June

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

Original Message ----- From: "Ryan" <ryan.gaffuri_at_cox.net> To: <oracle-l_at_freelists.org> Sent: Saturday, February 14, 2004 1:13 AM Subject: how does oracle store cursors in memory?

I know that data blocks are stored in the sga in linked lists. When hash maps are created the data blocks are stored in the pga as part of the hash map in arrays/linked lists.
How are cursors stored? Now the data for the cursors is going to be in the SGA. Is a cursor just a pointer to the memory location of the data in the SGA? Now I know a 'REF' cursor is basically a named pointer. Am I correct? What data structure does oracle use to store cursors?

Please see the official ORACLE-L FAQ: http://www.orafaq.com

To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line.

--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------

Received on Sat Feb 14 2004 - 03:48:40 CST