Re: On partitioning

On Mon, Dec 8, 2014 at 2:58 PM, Josh Berkus <josh@agliodbs.com> wrote:
>> I think any new partitioning system should keep the good things about
>> the existing system, of which there are some, and not try to reinvent
>> the wheel.  The yard stick for a new system shouldn't be "is this
>> different enough?" but "does this solve the problems without creating
>> new ones?".
>
> It's unrealistic to assume that a new system would support all of the
> features of the existing inheritance partitioning without restriction.
>  In fact, I'd say that such a requirement amounts to saying "don't
> bother trying".
>
> For example, inheritance allows us to have different indexes,
> constraints, and even columns on partitions.  We can have overlapping
> partitions, and heterogenous multilevel partitioning (partition this
> customer by month but partition that customer by week).  We can even add
> triggers on individual partitions to reroute data away from a specific
> partition.   A requirement to support all of these peculiar uses of
> inheritance partitioning would doom any new partitioning project.

I don't think it has to be possible to support every use case that we
can support today; clearly, a part of the goal here is to be LESS
general so that we can be more performant.  But I think the urge to
change too many things at once had better be tempered by a clear-eyed
vision of what can reasonably be accomplished in one patch.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company