Date: Fri, 21 Nov 2025 16:08:15 -0800
From: dolan@directdemocracysolutions.com
To: pgsql-general@lists.postgresql.org
Message-ID: <5031a50c-aca7-4512-9478-95583606b5ff@Spark>
Subject: FK from logged to unlogged table?
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Precedence: bulk

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Hello,

I'm looking to improve bulk write performance on a table of about 23 million rows by setting it unlogged. If lost, the table can be re-generated from archived raw data. The unlogged table would be referenced from a different, logged, table by a sparse but very important foreign key.

If the unlogged table is lost, I can repair the foreign key data by re-uploading the raw data and following a different unique key. However, this would be annoying and I would rather not have to implement it if I can protect the keyed records instead.

1. Is it allowed to key from a logged table to an unlogged table?
2. What is the system behavior if the unlogged table is lost?
3. Is there a clean way to protect only the subset of records that are keyed? (Yes, I am considering periodic backups to an archive table, but there would still be some repair needed that way).


Thanks! Nice to meet you all.
-Dolan

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<div>Hello,</div>
<div>&=23160;</div>
<div>I'm looking to improve bulk write performance on a table of about 23=
 million rows by setting it unlogged. If lost, the table can be re-genera=
ted from archived raw data. The unlogged table would be referenced from a=
 different, logged, table by a sparse but very important foreign key.</di=
v>
<div>&=23160;</div>
<div>If the unlogged table is lost, I can repair the foreign key data by =
re-uploading the raw data and following a different unique key. However, =
this would be annoying and I would rather not have to implement it if I c=
an protect the keyed records instead.</div>
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<li>Is it allowed to key from a logged table to an unlogged table=3F</li>=

<li>What is the system behavior if the unlogged table is lost=3F</li>
<li>Is there a clean way to protect only the subset of records that are k=
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<div>&=23160;</div>
<div>Thanks=21 Nice to meet you all.</div>
<div>-Dolan</div>
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