On 23-May-06, at 10:24 AM, Richard Huxton wrote:
Dhanaraj M wrote:
I have the following doubts.
1. Does postgres create an index on every primary key? Usually,
queries are performed against a table on the primary key, so, an
index on it will be very useful.
Yes, a unique index is used to enforce the primary-key.
2. If 'm executing a complex query and it takes 10 seconds to
return the results -- it takes 10 seconds to execute the next time
also. I'm wondering if there's any kind of caching that can be
enabled -- so, the next time it takes <10 seconds to return the
results.
Not of query results. Obviously data itself might be cached. You
might want to look at memcached for this sort of thing.
Postgresql relies on the kernel buffers, and shared buffers for caching.
As someone else said postgresql is quite conservative when shipped.
Tuning helps considerably
Dave
--
Richard Huxton
Archonet Ltd
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