You'll find that PostGIS does a pretty good job of selectivity
estimation.
P
On 13-Feb-07, at 9:09 AM, Guillaume Smet wrote:
Hi all,
Following the work on Mark Stosberg on this list (thanks Mark!), I
optimized our slow proximity queries by using cube, earthdistance
(shipped with contrib) an
ive_cache_size
--
1000
(1 row)
I have used the manual pages on postgresql, postmaster, and so on, but
I cant find anywhere to specify which config file Pg is to use. I'm
not entirely sure if he uses the one im editing
(/usr/local/etc/postgresql.conf).
Any hints,
Some tips:
- EXPLAIN ANALYZE provides a more useful analysis of a slow query,
because it gives both the estimate and actual times/rows for each step
in the plan.
- The documentation is right: rows with little variation are pretty
useless to index. Indexing is about "selectivity", reducing th
Doug Y wrote:
For idle persistent connections, do each of them allocate the memory
specified by this setting (shared_buffers * 8k), or is it one pool used
by all the connection (which seems the logical conclusion based on the
name SHARED_buffers)? Personally I'm more inclined to think the latt
