Hello Scott,
Scott Marlowe wrote:
On Mon, 2005-03-28 at 15:43, T E Schmitz wrote:
How expensive would it be to maintain the following VIEW:
CREATE VIEW origin AS SELECT DISTINCT origin FROM transaktion
if there is in index on transaktion.origin; the table transaktion has thousands of records and there are only a few distinct origin?
The cost will only be encurred when running the view. if you want materialized views (which WOULD have maintenance costs) you'll have to
Thank you for the pointer - that might come in handy for another scenario.
The cost of executing that view should be the same as the cost of running the query by hand.
I did an EXPLAIN ANALYZE and a sequential scan was carried out despite the index I had on the column. Maybe this is because I only have very few records in my test DB.
Would the "SELECT DISTINCT origin" always cause a sequential table scan regardless whether there is an index on the origin column or not?
--
Regards/Gruß,
Tarlika Elisabeth Schmitz
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