Re: Predicate locking - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Predicate locking
Date
Msg-id BANLkTi=K-2KzHrjAqtWr72yjTC8ho_k1yg@mail.gmail.com
Whole thread Raw
In response to Re: Predicate locking  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: Predicate locking  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
List pgsql-hackers
On Tue, May 3, 2011 at 10:07 PM, Kevin Grittner
<Kevin.Grittner@wicourts.gov> wrote:
> ... on a toy table with contrived values.  How different is this
> from the often-asked question about why a query against a four-line
> table is not using the index they expect, and how can we expect it
> to scale if it doesn't?  I agree that it's not unreasonable for
> someone to ask either question.  If my response falls short, I'm
> game to try again.

I guess what surprises me about this a bit is that we have to
predicate-lock the whole table even if we're not actually looking at
all the rows.  I can sort of see why that's necessary, but I'm a bit
fuzzy on the details, and it does seem a little unfortunate in this
instance...

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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