Re: Extraordinarily slow!!

Tom Lane wrote:

>"Justin R. Smith" <jsmith@drexel.edu> writes:
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>>I've solved the problem.
>>
>>
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>>I was accessing Postgres over an ssh connection and had enabled X
>>forwarding in the sshd server (not the default configuration). For
>>reasons that pass understanding, psql attempts to establish an X
>>connection with EACH elementary operation it performs (unless no such
>>connection is possible). It doesn't actually USE this X connection for
>>anything as far as I know, but the attempt to make the connection over a
>>slow communication line creates an enormous delay,
>>
>>
Now this was happening with external commands like create_user and
create_db?

If so, I would expect you have a really weird library issue.  In this
case, a stack trace on a hung process might be very informative.

If not, check your PAGER settings (I find that although I normally
prefer less, more is better in this case).

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>>Reconfiguring the sshd server to NOT forward X connections solved the
>>problem. Database operations take fractions of a second now...
>>
>>
It still seems likely that you will want to track this down in case
something else is wrong that you only discover later.

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>>Interestingly, it does NOT help to have X forwarding turned off only in
>>the client: sshd itself must not do any forwarding.
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>[ scratches head... ]  That makes no sense at all.  psql doesn't even
>know what X is, let alone try to open X connections for every database
>operation.
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>Is it conceivable that the openssl library would do this?  That would
>seem pretty broken too.
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Something is broken.  That is for sure.  And it probably isn't
PostgreSQL....

>How are you using ssh to access the database, exactly?  Is psql running
>through a tunnel port, or what?  What versions of ssl/ssh at each end of
>the connection?
>
>            regards, tom lane
>
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