Re: Update blocking a select count(*)?

[Benedict Holland <benedict.m.holland@xxxxxxxxx>]

I ran the scripts on the page and both returned empty (though I have queries running and currently nothing blocks). I don't know what they should have been. The output was from PgAdmin3 which is a UI for postgres. I assume that they get this queried information from something inside of postgres as I can't imagine the query tool doing something other than querying the database for specs. I think it looks at the PID. This very well might be a PgAdmin issue and have nothing to do with postgres.

~Ben

On Fri, Jun 15, 2012 at 4:00 PM, Kevin Grittner <Kevin.Grittner@xxxxxxxxxxxx> wrote:

Benedict Holland <benedict.m.holland@xxxxxxxxx> wrote:

> Is it a bug that the blocking process reported is the finial
> process but really the process blocking the intermediate?

What reported that?  The PostgreSQL server doesn't report such
things directly, and I don't know pgadmin, so I don't know about
that tool.  I wrote the recursive query on this page:

http://wiki.postgresql.org/wiki/Lock_dependency_information

So if that reported anything incorrecly, please let me know so I can
fix it.

By the way, the example with the three connections would have been
better had I suggested a BEGIN TRANSACTION ISOLATION LEVEL
REPEATABLE READ; on the third connection.  With that, even if one or
both of the transactions on the other connections committed, the
third transaction's count should remain unchanged.

-Kevin