Re: getting the most of out multi-core systems for repeated complex SELECT statements

On Thu, Feb 3, 2011 at 9:00 PM, Greg Smith <greg(at)2ndquadrant(dot)com> wrote:
> Andy Colson wrote:
>>
>> Cpu's wont get faster, but HD's and SSD's will.  To have one database
>> connection, which runs one query, run fast, it's going to need multi-core
>> support.
>
> My point was that situations where people need to run one query on one
> database connection that aren't in fact limited by disk I/O are far less
> common than people think.  My troublesome database servers aren't ones with
> a single CPU at its max but wishing there were more workers, they're the
> ones that have >25% waiting for I/O.  And even that crowd is still a subset,
> distinct from people who don't care about the speed of any one core, they
> need lots of connections to go at once.

The most common case where I can use > 1 core is loading data. and
pg_restore supports parallel restore threads, so that takes care of
that pretty well.