Thank you for your help. I found that an implicit index is created for
the primary key in the current version. However, it is not done in 7.x
version.
Mark Woodward 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.
>>
>>
>
>Well, here is an interesting question that I have suddenly become very
>curious of, if you have a primary key, obviously a unique index, is it, in
>fact, use this index regardless of analyzing the table?
>
>
>
>
>>>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.
>>
>>
>
>
>I am looking at this string of posts and it occurs to me that he should
>run analyze. Maybe I'm jumping at the wrong point.
>
>