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From: Tom Lane <[email protected]>
To: Tomas Vondra <[email protected]>
Cc: James Finnerty <[email protected]>
Cc: [email protected]
Subject: Re: postgres_fdw: using TABLESAMPLE to collect remote sample
Date: Fri, 30 Dec 2022 23:42:24 -0500
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
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Tomas Vondra <[email protected]> writes:
> After thinking about it a bit more I decided to rip out the 10% sampling
> rate inflation.

+1.  I'm not sure if there's anything more we need to do there, but
that didn't seem like that was it.

I notice that the committed patch still has a reference to that hack
though:

+            * Ensure the sampling rate is between 0.0 and 1.0, even after the
+            * 10% adjustment above.  (Clamping to 0.0 is just paranoia.)

Clamping still seems like a wise idea, but the comment is just
confusing now.

Also, I wonder if there is any possibility of ANALYZE failing
with

ERROR:  TABLESAMPLE clause can only be applied to tables and materialized views

I think the patch avoids that, but only accidentally, because
reltuples will be 0 or -1 for a view.  Maybe it'd be a good
idea to pull back relkind along with reltuples, and check
that too?

			regards, tom lane

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