Обсуждение: After vacuum db size is increasing
Hi Postgres Admins Any help is much appreciated . When i am running vacuum full, the database size is getting increased a lot, my database wasaround 100gb and when i did vacuum full on the large table ( which consume 95% of data in the database) , database sizebecome 200+ gb , then i did a full vacuum on the database itself and that made the db grow to 300+gb 🙄 and filled mydata drive . The large table size is showing only 80gb. I am running Postgres on windows. Anybody know why its behaving like this Thanks in advance Regards Sri Sent from my iPhone
It is a misconception that VACUUM will decrease allocated diskspace. PG is allocating tablespace, used by data or not. If it needs more, it will extend those. Downsize of this ( pun intended ) that tablespaces normally *don't* shrink. You saying your database is only using 80Gb but this is only 80Gb of *data*. That 80Gb is probably used within the tablespace mentioned. I don;t know the setup of your database but it sounds to me, your tablespace is extended during the VACUUM operation for whatever reason.. (Temporary space?) It seems odd to me that it "adds" the exact amount of space as it was initially... -- Open Systems Development B.V. Peter M. Groen ( Managing Director ) Rooseveltstraat 18-P 2321 BM Leiden Mob : +31 6 81 10 35 37 Email : peter@osdev.nl Slype : peter_m_groen On Mon, 2021-08-16 at 12:20 -0400, srijith s wrote: > Hi Postgres Admins > > Any help is much appreciated . When i am running vacuum full, the > database size is getting increased a lot, my database was around > 100gb and when i did vacuum full on the large table ( which consume > 95% of data in the database) , database size become 200+ gb , then i > did a full vacuum on the database itself and that made the db grow to > 300+gb 🙄 and filled my data drive . > The large table size is showing only 80gb. > > I am running Postgres on windows. Anybody know why its behaving like > this > > Thanks in advance > Regards > Sri > > > > > > Sent from my iPhone > >
On Mon, Aug 16, 2021 at 12:20 PM srijith s <udbdoctor@gmail.com> wrote:
Hi Postgres Admins
Any help is much appreciated . When i am running vacuum full, the database size is getting increased a lot, my database was around 100gb and when i did vacuum full on the large table ( which consume 95% of data in the database) , database size become 200+ gb , then i did a full vacuum on the database itself and that made the db grow to 300+gb 🙄 and filled my data drive .
The large table size is showing only 80gb.
I am running Postgres on windows. Anybody know why its behaving like this
Thanks in advance
Regards
Sri
Sent from my iPhone
Running a VACUUM FULL is essentially rewriting the entire table. While it is running, it is making a secondary copy of the object given. Doing this on a single table could use up to double the size of the existing table while it is running. It is also generating WAL files in addition to this which will take up even more space.
After it completes, then and only then, will you get your space back. And it will all depend on how much space was actually bloat to begin with.
It is recommended to keep an eye on your database's disk space and never let it grow above 75% usage for these very sorts of situations. Often to reclaim space in PostgreSQL you must use additional space to reclaim it back.