If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

 
Go Back  dBforums > Database Server Software > DB2 > How DBMS determines shared/private sort

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 01-01-04, 05:18
pushp pushp is offline
Registered User
 
Join Date: Aug 2003
Location: India
Posts: 30
Question How DBMS determines shared/private sort

Hi All,

Can anybody explains How the database manger /Optimizer determines sort will be of kind shared or private, because in each case memory sources are different .

Appreciates your quick response
Reply With Quote
  #2 (permalink)  
Old 01-01-04, 07:24
sathyaram_s sathyaram_s is offline
Super Moderator
 
Join Date: Aug 2001
Location: UK
Posts: 4,534
Re: How DBMS determines shared/private sort

A shared sort happens when the co-ordinator agent 'spawns' subagents to perform a bit of SQL ... Memory is allocated from the database shared memory, so that all the sub-agents can use the memory for sorting ... This happens when INTRA_PARALLEL is set to YES ..

A private sort happens when the co-ordinator agent executes the SQL ... Memory is allocated from the agent's private memory ...

Even if INTRA_PARALLEL is enabled, depending on the query, the optimizer may decide to use private sorts ...

HTH

Sathyaram

Quote:
Originally posted by pushp
Hi All,

Can anybody explains How the database manger /Optimizer determines sort will be of kind shared or private, because in each case memory sources are different .

Appreciates your quick response
__________________
Visit the new-look IDUG Website , register to gain access to the excellent content.
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On