[ZODB-Dev] pack script for RelStorage

[Shane Hathaway]

Eric Brun wrote:
> My pack take 2 days !
> And my db have the same size as before start packing :-(

That is to be expected; with PostgreSQL, you need to vacuum after 
packing, and even then, it prefers not to actually give back the space 
unless you "vacuum full".  You should enable the autovacuum feature, 
which is enabled by default in PostgreSQL 8.2.

> I don't have time for test with log , sorry.

That makes it hard to help you, unfortunately.

> We have a problem with huge Plone site that is very slow.
> With RelStorage , we hoped a bit fix this.
> 
> Have you experience of RelStorage on huge DB ?

Some, yes.  The main issue right now does appear to be pack speed.

> Now I test it with Postgresql 8.1 and pgpool2.
> What is the best pratice in the domain (config, clusering ...)?

Well, I've come to learn that 10K+ RPM drives and a good RAID controller 
will probably help a lot.  Make sure the fsync option is enabled since 
it improves the consistency of write speed.  Make sure the max_fsm_pages 
parameter is set high enough to allow vacuum to actually work (use 
"vacuum verbose" to find out how high it needs to be set).  More 
information will come as more people use it.

Shane