[Pgcluster-general] slow data-read performances

[Julien Garet]

Hi,

    I've just setup a testing cluster of postgresql with pglcuster and 
there is something and do understand with the perfs. My setup is quite 
simple, I have two identical boxes with database and replicator under 
centos 5, it works well. I have done some testing  with pgbench and a 
third identical box running postgres 8.3 without postgres as reference.
     The number of tps is about 5 times less in the cluster compared to 
the reference box, using all kind of queries of pgbench (1 select, 1 
insert et 3 update), which is quite normal, due to the overhead of the 
cluster in writing data. But when I use pgbench, only using select 
queries, the nodes of the cluster are still 5 times slower than the 
reference postgresql server. And I don't understand that as pgcluster 
isn't supposed to replicate data-read queries between nodes, the 
data-read performances should be the same as the reference. Are there 
any clues to this mysterious thing ?

Julien

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