[ZODB-Dev] Re: ZODB Benchmarks

2007-11-01 Thread Matt Hamilton
Laurence Rowe l at lrowe.co.uk writes: So why is PosgreSQL so much faster? It's using a Write-Ahead-Log for inserts. Instead of inserting into the (B-Tree based) data files at every transaction commit it writes a record to the WAL. This does not require traversal of the B-Tree and has O(1)

Re: [ZODB-Dev] Re: ZODB Benchmarks

2007-11-01 Thread Roché Compaan
On Wed, 2007-10-31 at 10:47 -0400, David Binger wrote: On Oct 31, 2007, at 7:35 AM, Roché Compaan wrote: Thanks for the explanation. The actual insertion is very fast. Your benchmark is dominated by the time to serialize the changes due to an insertion. You should usually have just 2

Re: [ZODB-Dev] Re: ZODB Benchmarks

2007-11-01 Thread Gary Poster
On Nov 1, 2007, at 4:25 PM, Matt Hamilton wrote: David Binger dbinger at mems-exchange.org writes: On Nov 1, 2007, at 7:05 AM, Matt Hamilton wrote: Ie we perhaps look at a catalog data structure in which writes are initially done to some kind of queue then moved to the BTrees at a later

Re: [ZODB-Dev] Re: ZODB Benchmarks

2007-11-01 Thread David Binger
On Nov 1, 2007, at 4:25 PM, Matt Hamilton wrote: David Binger dbinger at mems-exchange.org writes: On Nov 1, 2007, at 7:05 AM, Matt Hamilton wrote: Ie we perhaps look at a catalog data structure in which writes are initially done to some kind of queue then moved to the BTrees at a later

Re: [ZODB-Dev] Re: ZODB Benchmarks

2007-11-01 Thread Russ Ferriday
Quick note... Smaller buckets, fewer conflicts, more overhead on reading and writing. Larger buckets, more conflicts, less overhead on reading and writing. One bucket ... constant conflicts. I'd bet that the additional tree with tiny buckets would be best. Transfer them into the normal tree