Re: Deterioration in performance when query executed in multi threads

Anne Rosset, 06.05.2013 19:00:
> Postgres version: 9.0.13
>
>> Work_mem is set to 64MB
>> Shared_buffer to 240MB
>> Segment_size is 1GB
>> Wal_buffer is 10MB
>
> Artifact table: 251831 rows
> Field_value table: 77378 rows
> Mntr_subscription: 929071 rows
> Relationship: 270478 row
> Folder: 280356 rows
> Item: 716465 rows
> Sfuser: 5733 rows
> Project: 1817 rows
>
> 8CPUs
> RAM: 8GB
>

With 8GB RAM you should be able to increase shared_buffer to 1GB or maybe even higher especially if this is a dedicated
server.
240MB is pretty conservative for a server with that amount of RAM (unless you have many other applications running on
thatbox) 

Also what are the values for

cpu_tuple_cost
seq_page_cost
random_page_cost
effective_cache_size

What kind of harddisk is in the server? SSD? Regular ones (spinning disks)?