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Home -> Community -> Mailing Lists -> Oracle-L -> Re: how does oracle store cursors in memory?
How does oracle store cursors in memory? In arrays, linked lists, etc...?
What about sql plans? I know they are hashed. So the hash is probably an array. Is it a pointer to a list? Or something else? Is the dictionary cache stored differently from the library cache?
>
> 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
>
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> ----- 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?
>
>
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-- 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 - 08:06:50 CST
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