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From: Gabriel Sánchez <[email protected]>
To: Postgres General <[email protected]>
Subject: Speeding up ANALYZE on large partitioned tables
Date: Wed, 1 Apr 2026 11:04:43 -0400
Message-ID: <CANHuRqGh4x4OAXwePkjhcN2QqCPFHoKxP7astnOUQRB8P0Eyag@mail.gmail.com> (raw)

Hi PostgreSQL community,

I have a database with several very large tables (for example, 86 GB) that
are partitioned by year, sub-partitioned by month, and sub-sub-partitioned
by day. Each day a new partition is added, and that partition is
immediately ANALYZEd by my process.

However I noticed that sometimes the query plans for queries on the
top-level partitioned table don't make much sense, and I read in the
documentation that ANALYEing the leaf partitions doesn't update the
statistics of the parent and grandparent tables. So I have to run ANALYZE
on the top-level table, and when I do that the query plan makes more sense.
But it takes quite a while to ANALYZE the 86 GB table with hundreds of
sub-sub=partitions, because that ANALYZE triggers an ANALYZE on each
partition down the tree. Since leaf tables are always ANALYZED when
created, isn't there a way to update the statistics of the parent and
grandparent tables based on the statistics already calculated for the
partitions? Maybe with an ANALYZE ONLY [top-level table]?

Thanks,
Gabriel

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