Subject: Grouper Developers Forum
- From: Chris Hyzer <>
- To: Grouper Dev <>
- Subject: flat membership views and change log view
- Date: Thu, 13 May 2010 00:03:16 -0400
- Accept-language: en-US
- Acceptlanguage: en-US
I added these DB views:
There are three new views with the same columns as the previous three lightweight membership views:
These are on the flattened tables. If you are seeing if a user is in a group or listing the members of a group or the groups of a user, then flat and nonflat have similar performance (at least a similar cost in oracle explain plan). However, if you do heavier things then the flat tables have much better performance.
e.g. select all memberships: SELECT * FROM grouper_memberships_lw_v
nonflat cost: 60,000
flat cost: 6,000
e.g. select all memberships that someone is allowed to read
FROM grouper_memberships_lw_v mships, grouper_memberships_lw_v privs
WHERE mships.GROUP_ID = privs.GROUP_ID
AND mships.list_name = 'members'
AND privs.list_name IN ('readers', 'admins')
AND privs.subject_source = 'abc'
AND privs.subject_id = 'def';
nonflat cost: 16,000
flat cost: 52
Bottom line if you are doing complex operations, and you can deal with a few minutes of propagation delay, then the flat views will be a more performant way to get your data...
- flat membership views and change log view, Chris Hyzer, 05/13/2010
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