Bert wrote:
No i didn't defined any indexes for the table, I know the performance
will increase with an index, but this was not my question. My question
furthermore belongs to the access mode of the SQL statement.
Furthermore i do not understand why the Upper function should increase
the performance.
The index will have entries like:
CHRIS
BERT
JOE
and so on.
If you run a query like:
select * from table where UPPER(name) = 'CHRIS';
It's an easy match.
If you don't create an UPPER index, it has to do a comparison with each
row - so the index can't be used because postgres has to convert the
field to upper and then do the comparison.
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