this post was submitted on 18 Aug 2023
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Lemmy PostgreSQL

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PostgreSQL usage in Lemmy is many JOIN (bulletintree.com)
submitted 1 year ago by [email protected] to c/[email protected]
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Some learning about JOIN filled queries like the SELECT that is used to list post_aggregates table when browsing postings on Lemmy.

https://dba.stackexchange.com/questions/155972/postgres-join-conditions-vs-where-conditions

"Logically, it makes no difference at all whether you place conditions in the join clause of an INNER JOIN or the WHERE clause of the same SELECT. The effect is the same. (Not the case for OUTER JOIN!)"

Learning about join_collapse_limit

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[–] [email protected] 1 points 1 year ago* (last edited 1 year ago)

Joins after Picking post list

Research:

https://dba.stackexchange.com/questions/211642/optimising-expensive-join-subquery-by-filtering-with-conditionals

More on LATERAL, including LIMIT before JOIN:
https://stackoverflow.com/questions/28550679/what-is-the-difference-between-a-lateral-join-and-a-subquery-in-postgresql
https://dba.stackexchange.com/questions/229214/how-to-apply-outer-limit-offset-and-filters-in-the-subquery-to-avoid-grouping-ov