Re: User Quota Implementation - Mailing list pgsql-hackers

From Jonah H. Harris
Subject Re: User Quota Implementation
Date
Msg-id 40EEC659.8070307@tvi.edu
Whole thread Raw
In response to Re: User Quota Implementation  (Alvaro Herrera <alvherre@dcc.uchile.cl>)
Responses Re: User Quota Implementation  (Alvaro Herrera <alvherre@dcc.uchile.cl>)
List pgsql-hackers
Quota is currently enforced on commit.  I've considered checking during 
insert/update/copy and throwing an abort but within a transaction they 
may be deleting data as well.

However, even as a delete may take place before a massive insert/update, 
a vacuum cannot be run within a transaction block and therefore the 
commit would fail at the same point as an insert/update within the 
transaction itself.

So, essentially, there is no difference at which point to check other 
than to reduce the calculation overhead by placing the check at the 
commit point.

What's the consensus on when to check?

Alvaro Herrera wrote:
> On Thu, Jul 08, 2004 at 03:27:34PM -0600, Jonah H. Harris wrote:
> 
> 
>>Out of necessity, I've implemented user quotas in 7.4.3.  What would the 
>>process be for having this reviewed and combined?  I have a patch for 
>>7.4.3 ready, but wanted to know if you suggest that I patch the latest 
>>cvs instead.  Below if some information on the implementation.
> 
> 
> At exactly what time is the quota enforced?  Does the enforcement
> somehow serialize that operation?
> 

-- 
Jonah H. Harris, UNIX Administrator  | phone: 505.224.4814
Albuquerque TVI                      | fax:   505.224.3014
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"All great truths begin as blasphemies."                --  George Bernard Shaw



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