A J <s5aly@yahoo.com> wrote:
> log_min_duration_statement output should stay constant for all the
> different clients across different geographic locations.
I'm not sure timings there will be totally immune to network speed.
The whole execution engine is designed around the top level pulling
rows from other levels. If it is sending those rows over the wire
as it pulls them, it could block at times, causing a delay before
completion of the query.
I haven't looked at the PostgreSQL wire protocol in detail, but
other database products where I became familiar with the wire
protocol had many round trips per query run -- making run time
sensitive to the network latency. I've generally gone with a thin
tier on the database server to field requests and provide responses
using stream-oriented protocols with moving windows so I can keep
the database protocol to the fastest, lowest latency connection I
can arrange. I like to use queues in that middle tier for incoming
requests and outgoing responses, to minimize the impact of network
throughput and latency.
-Kevin