Re: Doing a query with string vs bind variables.
- From: yf110@xxxxxxxxxxxxxxxxxxx (Malcolm Dew-Jones)
- Date: 17 Sep 2007 19:04:34 -0800
Luch (DarthLuch@xxxxxxxxx) wrote:
: We have a PowerBuilder application where we started noticing the
: performance of a query is worse if you do it with bind variables then
: if you do the same query as a string.
Bind variables minimize the number of times a query must be parsed. That
is likely to speed up your application if the same queries are used
multiple times.
Hard coded values allow the optimizer to select the best possible path to
select the data. That is likely to speed up your application if a query
is only run once, or if the time to parse the query is small compared to
the time it takes to run the query, especially if the values are unusual
compared to most of the data.
Apparently more recent versions of Oracle (version?) will examine the
values of bind variables before running a query as a sanity check that the
existing parsed query will still be sensible for those values. I know not
the exact details.
$0.10
.
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- Doing a query with string vs bind variables.
- From: Luch
- Doing a query with string vs bind variables.
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