we were able to use a brin index for our time-series data and that saved
a lot of space. basically, we used a btree for recent data and, once the
data was "stable", reclustered the data to get high correlation on the
brin index, created a brin index and dropped the btree. it works well.
On 4/15/2019 1:42 AM, Ray Cheung wrote:
> Hi ,
>
> We are currently contemplating switching from MySQL to PostgreSQL, the main
> attraction being the use of the TimescaleDB extension. Having done much of
> the ground investigation there is one area of significant concern - the
> storage requirement of PostgreSQL. Put simply, comparing like for like for a
> set of tables, PostgreSQL consumes far more storage space than MySQL:
>
> - MySQL (5.6): 156 MB
> - PostgreSQL (11.2): 246 MB
> - PostgreSQL + TimescaleDB (partitioned/chunked data): 324 MB
>
> I've also submitted this in stackoverflow:
> https://stackoverflow.com/questions/55655272/how-to-reduce-postgresql-databa
> se-size.
>
> I can rearrange the table/column-alignment to save 6 bytes per row of the
> main table, with a saving of a few mega-bytes. Not enough to make any real
> difference. Does anyone know:
>
> - Why PostgreSQL is so storage inefficient in comparison?
> - What existing methods can be used to reduce the storage consumption (I've
> already tried realignment and vacuum full)?
> - Are there any plans to address this storage consumption inefficiency (in
> comparison to MySQL) problem?
>
> Many thanks,
>
> sps-ray
>
>
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