performance tuning - splitting data and logs

[kraada]

You're welcome and I'm glad we could get things sorted out for you

[Traclugator]

Creating simlinks is quite scary for me
Would it be safer and easier to just paste the new path into .conf file instead of
#log_directory = 'pg_log'
in the section "ERROR REPORTING AND LOGGING" ?

[kraada]

That should work as well.

[Traclugator]

That should work as well.

What decision will be best for performance - tablespace on a fast (10k RPM) system HDD and logs on a spare disk (7200 RPM) or vise versa?

[WhiteRider]

Having your database on the fastest drive will give you the best performance. Writing logs to a separate disk will help because all the disk access on the DB drive will be concentrated on database access.

[Traclugator]

Having your database on the fastest drive will give you the best performance. Writing logs to a separate disk will help because all the disk access on the DB drive will be concentrated on database access.

Ty

[Traclugator]

OMG, looks that i was wrong.
The biggest disk usage is because of WRITE AHEAD LOG, but it seems to me that
#log_directory = 'pg_log'
is NOT for WRITE AHEAD LOG but only for error reporting
Write ahead dir. does not seem to be changed in conf file.

[Traclugator]

In my case i type
c:\Junction\junction c:\Program Files\PostgreSQL\8.3\data\pg_xlog "P:\PGSQL_WAL\XP"
but it always says

Error setting junction for c:\Program Files\PostgreSQL\8.3\data\pg_xlog:
????? ?? ?????.

I don't know what is ????? ?? ?????. looks like locale problem

[WhiteRider]

...it seems to me that
#log_directory = 'pg_log'
is NOT for WRITE AHEAD LOG but only for error reporting

The # comments out the line. To change configuration you need to remove the #.

[Traclugator]

At last i've made all the junctions needed! But why my pg_xlog DIR is 850MB? Can i chanje it somehow?