Re: ALTER TABLE ADD COLUMN fast default - Mailing list pgsql-hackers

On 20/02/18 07:42, Andres Freund wrote:
> Hi,
> 
> On 2018-02-17 00:23:40 +0100, Tomas Vondra wrote:
>> Anyway, I consider the performance to be OK. But perhaps Andres could
>> comment on this too, as he requested the benchmarks.
> 
> My performance concerns were less about CREATE TABLE related things than
> about analytics workloads or such, where deforming is the primary
> bottleneck.  I think it should be ok, but doing a before/after tpc-h of
> scale 5-10 or so wouldn't be a bad thing to verify.
> 

The test Tomas is doing is analytical query, it's running sum on the new
fast default column.

He uses create and create-alter names as comparison between when the
table was created with the columns and when the columns were added using
fast default.

-- 
  Petr Jelinek                  http://www.2ndQuadrant.com/
  PostgreSQL Development, 24x7 Support, Training & Services