Re: Cluster and Vacuum Full - Mailing list pgsql-general

From Guillaume Lelarge
Subject Re: Cluster and Vacuum Full
Date
Msg-id CAECtzeWAx+GOHaj58YoGFphVK22ahykBRVuPqi17efODGJM+5A@mail.gmail.com
Whole thread Raw
In response to Cluster and Vacuum Full  (PegoraroF10 <marcos@f10.com.br>)
List pgsql-general
Le lun. 5 oct. 2020 à 12:22, PegoraroF10 <marcos@f10.com.br> a écrit :
I have tables which are Master Detail and usually my program loads all detail
records of a master record. So I configured CLUSTER on all those detail
tables to use an index which is the relation with master table. With that I
can load less records to Shared Buffers because all detaild records are on
sequencial pages, that´s fine.

I know that to have this working I have to periodically run CLUSTER, ok too.

But today instead of CLUSTER I just ran VACUUM FULL. How vacuum full
recreates entirelly that table, like cluster does, I thought it would use
that index too, but didn´t. I didn´t see what sequence of records it did but
was not the one I´ve configured with cluster.

Is that expected or Vacuum should obbey cluster configuration ?


Only CLUSTER obeys cluster configuration. VACUUM FULL in particular doesn't.


--
Guillaume.

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