Re: Simple postgresql.conf wizard

I profiled this on CVS HEAD.  First, I set this up:

> postgres=# create table tk as select
random()::text||random()::text||random()::text||random()::text||random()::text||random()::textas r from
generate_series(1,1000);
> postgres=# insert into tk (select * from tk);
> postgres=# insert into tk (select * from tk);
> postgres=# insert into tk (select
random()::text||random()::text||random()::text||random()::text||random()::text||random()::textas r from
generate_series(1,2000));
> postgres=# alter table tk alter r set statistics 1000;
> postgres=# analyze tk;

Then I profiled a backend that executed the following query 10x
(uparrow-enter 10 times from psql):

> postgres=# explain select count(*) from (select * from tk as k, tk as l,tk as m,tk as n,tk as o,tk as p where k.r=l.r
andk.r=m.r and k.r=n.r and k.r=o.r and k.r=p.r) as x; 

Results:

  %   cumulative   self              self     total
 time   seconds   seconds    calls   s/call   s/call  name
 77.73      1.92     1.92     5500     0.00     0.00  pglz_decompress
  6.07      2.07     0.15      250     0.00     0.00  eqjoinsel
  1.62      2.11     0.04  2009500     0.00     0.00  varstr_cmp
  1.21      2.14     0.03  3502500     0.00     0.00  datumCopy
  1.21      2.17     0.03     3500     0.00     0.00  deconstruct_array
  1.21      2.20     0.03                             MemoryContextContains

Full results attached.

...Robert