Re: Autovacuum------Doubts

On Mon, 2024-04-08 at 14:57 +0530, jaya kumar wrote:
> autovacuum_analyze_threshold and autovacuum_vacuum_threshold both parameter
> values set from 50 to 20.
>
> Created one table with 100 records. First, we deleted 21 records. after an
> autovacuum does not happen automatically. After again I deleted another 20.
> Out of 100 we delectated 40 records then the autovacuum happened automatically.
> As per the configuration Autocacuum will automatically delete 21 records
> in the table but my case does not happen.
>
> Can someone check and explain this.

The threshold is

  autovacuum_vacuum_threshold + autovacuum_vacuum_scale_factor * number of table rows

So since you have set autovacuum_vacuum_scale_factor to 0.1 and there are 100 rows,
you need to delete 20 + 100 * 0.1 = 30 rows before autovacuum kicks in.

Yours,
Laurenz Albe