Re: rebuild big tables with pgrepack

Hi Ron,

So basically, we need to have twice the space of the table and its indexes available before performing a repack, right?

On Fri, Nov 14, 2025 at 8:47 PM Ron Johnson <ronljohnsonjr@gmail.com> wrote:

On Fri, Nov 14, 2025 at 2:14 PM ek ek <livadidrive@gmail.com> wrote:

Hello everyone,

I’m going to rebuild a 900GB table using pg_repack. I’m hesitant to do such a large operation in one go.

Is there an ideal or recommended way to repack very large tables?

Everything in database maintenance is circumstantial.

The basics that I'd do are:

* Verify that you have enough free disk space for both the new table, the new indices and also the WALs generated.

* Do it during a low-activity window.

* Don't run a database backup at the same time.

* First execute with --dry-run.

* Consider the --no-order option.  That'll speed things up.

* And --no-analyze, though you'll have to manually ANALYZE immediately afterwards.

* (I'd probably disable autoanalyze on that table before the repack and then enable it after the manual ANALYZE.)

* The --jobs option speeds up index rebuilds.

* Run it from cron, and redirect both stdout and stderr to the same log file.

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