Re: Postgres as In-Memory Database?

On 18/11/13 12:53, Stefan Keller wrote:
> Hi Martijn
>
> 2013/11/17 Martijn van Oosterhout <kleptog(at)svana(dot)org
> <mailto:kleptog(at)svana(dot)org>> wrote:
>
> > If your dataset fits in memory then the problem is trivial: any decent
> > programming language provides you with all the necessary tools to deal
> > with data purely in memory.
>
> What about Atomicity, Concurrency and about SQL query language and the
> extension mechanisms of Postgres? To me, that's not trivial.
>
> > There are also quite a lot of databases that cover this area.
>
> Agreed. That's what partially triggered my question, It's notably
> Oracle TimesTen, MS SQL Server 2014 (project Hekaton), (distributed)
> "MySQL Cluster", SAP HANA or SQLite >3. To me this rather confirms
> that an architecture and/or configuration for in-memory could be an
> issue also in Postgres.
>
> The actual architecture of Postgres assumes that memory resources are
> expensive and optimizes avoiding disk I/O. Having more memory
> available affects database design e.g. that it can optimize for a
> working set to be stored entirely in main memory.
>
> --Stefan
>
[...]

It would allow optimised indexes that store memory pointers of
individual records, rather than to a block & then search for the record
- as well as other optimisations that only make sense when data is known
to be in RAM (and RAM is plentiful). As already big severs can have a
TerraByte or more of RAM, that will become more & more common place. I
have 32GB on my development box.

Cheers,
Gavin