My postgres DB has 20 GB of storage space available but when running a DELETE the space decreases to ~4 GB before increasing again to ~14 GB. I understand that deletions will not return reclaimed space because of the MVCC (want to eventually run a FULL VACUUM on that table) but am confused as to why it went down to ~14 GB from 20 GB ultimately. Additionally, the auto-vacuum did run and was assuming this is why it went down to ~4GB first then went back up..still the return of available storage space happened a good amount of time after the auto vacuum ran so is this an incorrect assumption? I would've assumed some space may still be taken from the
DELETEs but 6GB was more than I was expecting.
- postgres DB on AWS has 20 GB of available storage space
- Storage space decreases to ~4 GB
- Auto Vacuum runs
- Time delay but some time after returns to ~14 GB
Unsure why it only returned to 14 GB instead of 20 GB.