Re: Slow response of PostgreSQL - Mailing list pgsql-performance

From Bill Moran
Subject Re: Slow response of PostgreSQL
Date
Msg-id 4032CC2B.9030208@potentialtech.com
Whole thread Raw
In response to Re: Slow response of PostgreSQL  ("scott.marlowe" <scott.marlowe@ihs.com>)
List pgsql-performance
scott.marlowe wrote:
> On Wed, 18 Feb 2004, Christopher Kings-Lynne wrote:
>
>>>>>1- How can I lock a single record so that other users can only read
>>>>>it. ??
>>>>
>>>>
>>>>You cannot do that in PostgreSQL.
>>>
>>>
>>>How about SELECT ... FOR UPDATE?
>>
>>No, because users cannot read the locked row in that case.
>
> I just tested it (within transactions) and it appeared that I could still
> view the rows selected for update.

Thank you.  I was just about to test it myself.

The user's guide, section 9.3.2 states that this is the case: i.e. select
for update will prevent concurrent updating of the row, while allowing
queries utilizing that row to succeed.

--
Bill Moran
Potential Technologies
http://www.potentialtech.com


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