Posted by David T. Ashley on 01/08/07 22:36

"Amar" <ghungur.2006@gmail.com> wrote in message
news:1168273543.258541.150800@42g2000cwt.googlegroups.com...
> Hi All,
>
> I need to select data from a database table containing huge amount of
> data. Now I am storing data using one primary key and I am just using
> simple select statement, and this process gives me the output but it is
> taking long to execute the query. As much I had heared I want to use
> some indexing or cluster indexing which might help me but I am not so
> familiar with these things. So if any one having some solutions to
> execute the query in short time period that may help me then please
> welcome...

Indexing means that a B-tree or similar structure is stored (the index) in
addition to the data. The index is a way to find specific values of a
specific field without searching every record in the database (assuming the
field type is ordered and there aren't a zillion duplicates).

In an approximate sense, the addition of the parallel data will change
SELECTs based on indexed data from O(N) to O(log N).

However, as Mr. Moller pointed out, it will make SELECTs faster, but will
slow down operations that involve adding or perhaps modifying records.

You can find a more lengthy explanation that might make sense here:

http://en.wikipedia.org/wiki/Btree

Dave.

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