Re: reindex option for tuning load large data

I believe you should be able to use reindexdb with parallel jobs:
https://www.postgresql.org/docs/13/app-reindexdb.html
It will still create multiple connections, but you won't need to run
multiple commands.

чт, 16 черв. 2022 р. о 22:34 James Pang (chaolpan) <chaolpan(at)cisco(dot)com>
пише:

> Hi ,
>
> We plan to migrate large database from Oracle to Postgres(version 13.6,
> OS Redhat8 Enterprise), we are checking options to make data load in
> Postgres fast. Data volume is about several TB, thousands of indexes,
> many large table with partitions. We want to make data load running fast
> and avoid miss any indexes when reindexing. There are 2 options about
> reindex. Could you give some suggestions about the 2 options, which option
> is better.
>
>
>
> 1. Create tables and indexes( empty database) , update pg_index set
> indisready=false and inisvalid=false, then load data use COPY from csv ,
> then reindex table …
>
> Reindex on Postgres 13.6 not support parallel ,right? So we need to start
> multiple session to reindex multiple tables/indexes in parallel.
>
>
>
>
>
> 2). Use pg_dump to dump meta data only , then copy “CREATE INDEX … sql “
>
> Drop indexes before data load
>
> After data load, increase max_parallel_maintenance_workers,
> maintenance_work_mem
>
> Run CREATE INDEX … sql to leverage parallel create index feature.
>
>
>
>
>
>
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> Thanks,
>
>
>
> James
>
>
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>