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DBA-C0052 · Configuration & Tuning

PostgreSQL WAL and Checkpoint Tuning

Draft one checkpoint note. Do not apply it. Do not turn fsync or full page writes off.

Updated 25 October 2026 · How-To

This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.

What this hour is for

The tuner drafts checkpoint and WAL numbers from figures you type. fsync stays on. full_page_writes stays on. Turning either off is not a way to make a check pass.

Do not change a live setting during the reading. One cluster, and you can name it.

192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. A sample password is replaced. It is not a password you keep.

The change you can finish

Apply nothing while you are writing the note. When the lab window opens, it is one change on the database named in the ticket. Read the draft, then the database, then decide.

Rollback is the backup, the file, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.

  1. Name the cluster or say sketch.
  2. Read the drafted numbers.
  3. Leave fsync on.
  4. Leave full page writes on.
  5. Do not apply.
  6. Stop.

Mistakes that outlive the statement

PostgreSQL WAL and Checkpoint Tuning goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.

Decisions to write down

One decision for PostgreSQL WAL and Checkpoint Tuning: The numbers were read. fsync stays on. full_page_writes stays on. And nothing was applied.

Checks before you call it done

Confirm this before you call the change done: The cluster is written or it is a sketch. The numbers were read. fsync stays on. Nothing was applied. And the database is yours. If one of those fails, stop.

# Checkpoint note. Do not apply it.
# fsync stays on.
# full_page_writes stays on.

Before you leave the database

PostgreSQL WAL and Checkpoint Tuning ends when the database in the prompt is the database in the ticket. If it is not, you are on the wrong database. Stop.

The draft stays a draft until a person has read the names in it. A generator does not log into the database. You delete a line that names a host, a database, or an account you did not write down.

192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a database because a draft included them.

prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. A sample password in a draft is replaced. It is not a password you keep.

One change is the window. If two things move and the result is wrong, you will not know which one did it.

If the same step fails twice, stop for the day. Restore the copy you took first.

A second person reads the database name and the change aloud. If they cannot find them in the ticket, the note is not done.

This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a database you do not administer. You do not disable authentication, a firewall, or TLS to make a check pass.

Tools for this guide

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More in this cluster

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