Sorry, typo on my part (I fixed my last post). Mixed it up with the work_mem setting
It is the Shared_buffer that you alter in the postgresql.conf file.
I haven't managed a Postgresql database before, but I know from working with Microsoft SQL Server you should make sure that you have enough RAM dedicated to SQL so it can load your entire database into RAM. This case no page swapping is needed to access any metadata.
SQL Server they make it very easy to check and change this by just right click on your database in Management Studio. But, with Postgresql you have to change the value in the conf file.
It should be put into documentation for this Project Server that this setting should be looked at.