Subject: Re: Large number of partitions of a table
To: pgsql-admin@lists.postgresql.org
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 <3919502.1642393668@sss.pgh.pa.us> <YeUAx56Juri43xGY@admin.sibptus.ru>
From: Ron <ronljohnsonjr@gmail.com>
Message-ID: <671340a5-1960-e5dc-1d09-4b7f36cda2c8@gmail.com>
Date: Mon, 17 Jan 2022 08:41:34 -0600
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On 1/16/22 11:38 PM, Victor Sudakov wrote:
> Tom Lane wrote:
> [dd]
>
>> The specific point that depesz was responding to in that blog
>> was the 64K-ish limit on rangetable entries in a query.  That is
>> a thing, as he could have shown by using queries that weren't
>> amenable to plan-time pruning.  (It's also an ex-thing, having
>> been fixed for v15 [1]; but that doesn't help you today.)
>> Now, if you use no queries that can't be pruned to a few
>> partitions, then it's academic for you.
> The table will be partitioned `BY LIST (customer_id)` which is a unique
> index. All queries will be using this index

Good.

> so no query should ever have to use more than 1 partition.

I find it hard to believe that you'll *never* run a report against more 
customers than are in a single partition.

>
> This means basically I'm OK?
>

-- 
Angular momentum makes the world go 'round.

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    On 1/16/22 11:38 PM, Victor Sudakov wrote:<br>
    <blockquote type="cite" cite="mid:YeUAx56Juri43xGY@admin.sibptus.ru">
      <pre class="moz-quote-pre" wrap="">Tom Lane wrote:
[dd]

</pre>
      <blockquote type="cite">
        <pre class="moz-quote-pre" wrap="">The specific point that depesz was responding to in that blog
was the 64K-ish limit on rangetable entries in a query.  That is
a thing, as he could have shown by using queries that weren't
amenable to plan-time pruning.  (It's also an ex-thing, having
been fixed for v15 [1]; but that doesn't help you today.)
Now, if you use no queries that can't be pruned to a few
partitions, then it's academic for you.  
</pre>
      </blockquote>
      <pre class="moz-quote-pre" wrap="">
The table will be partitioned `BY LIST (customer_id)` which is a unique
index. All queries will be using this index </pre>
    </blockquote>
    <br>
    Good.<br>
    <br>
    <blockquote type="cite" cite="mid:YeUAx56Juri43xGY@admin.sibptus.ru">
      <pre class="moz-quote-pre" wrap="">so no query should ever have to use more than 1 partition.</pre>
    </blockquote>
    <br>
    I find it hard to believe that you'll <b>never</b> run a report
    against more customers than are in a single partition.<br>
    <br>
    <blockquote type="cite" cite="mid:YeUAx56Juri43xGY@admin.sibptus.ru">
      <pre class="moz-quote-pre" wrap="">

This means basically I'm OK?

</pre>
    </blockquote>
    <br>
    <div class="moz-signature">-- <br>
      Angular momentum makes the world go 'round.</div>
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