Обсуждение: transaction ID wraparound - should I use 'VACUUM' or 'VACUUM FULL' ?
Hi, In old version of Postgres we have to execute 'VACUUM FULL' to solve problem of transaction ID wraparound, do we need to execute 'VACUUM FULL' in Postgres 8.3 or 8.4 to avoid this problem? How to check using SQL if transaction ID is close to wraparound? Michal Szymanski http://blog.szymanskich.net
Michal Szymanski wrote: > Hi, > In old version of Postgres we have to execute 'VACUUM FULL' to solve > problem of transaction ID wraparound, do we need to execute 'VACUUM > FULL' in Postgres 8.3 or 8.4 to avoid this problem? No, plain VACUUM suffices. > How to check using SQL if transaction ID is close to wraparound? See age(datfrozenxid) FROM pg_database, but ignore system databases. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
Alvaro Herrera <alvherre@commandprompt.com> writes:
> Michal Szymanski wrote:
>> In old version of Postgres we have to execute 'VACUUM FULL' to solve
>> problem of transaction ID wraparound, do we need to execute 'VACUUM
>> FULL' in Postgres 8.3 or 8.4 to avoid this problem?
> No, plain VACUUM suffices.
Just to clarify: plain VACUUM has always sufficed; in *no* version of
Postgres has it ever been the case that VACUUM FULL was more useful
than VACUUM to protect against wraparound.
regards, tom lane
On 10 Paź, 04:38, t...@sss.pgh.pa.us (Tom Lane) wrote: > Alvaro Herrera <alvhe...@commandprompt.com> writes: > > Michal Szymanski wrote: > >> In old version of Postgres we have to execute 'VACUUM FULL' to solve > >> problem of transaction ID wraparound, do we need to execute 'VACUUM > >> FULL' in Postgres 8.3 or 8.4 to avoid this problem? > > No, plain VACUUM suffices. > > Just to clarify: plain VACUUM has always sufficed; in *no* version of > Postgres has it ever been the case that VACUUM FULL was more useful > than VACUUM to protect against wraparound. > > regards, tom lane For me it was clear that plain VACUUM is enough but my friend had situation when wraparound happend when he used plain vaccum after 'vacuum full' prblem was solved. I will change our vacuum full to plain vacuum and we will see what happen. Regards Michal Szymanski