Re: SQL Deterministic UDF and File Read Count

[rob@xxxxxxxxx]

It could be interpreted to mean that, even though I will return the same 
value as the last call if the input parameter(s) are all alike it doesn't 
mean that I will not still execute the UDF.  The deterministic just 
returns the result set from cache.  How this improves performance (since 
it calls the UDF anyway) I don't know.  But that just might be my own 
limitations.

Rob Berendt
-- 
Group Dekko Services, LLC
Dept 01.073
PO Box 2000
Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com





"Bill" <BillZBubb@xxxxxxxxxx> 
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02/15/2005 12:40 PM
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Subject
SQL Deterministic UDF and File Read Count






I have created an SQL UDF which is specified as Deterministic.  The UDF is
written in RPGLE and accesses a table as part of it's logic.  When I do a
Select statement in SQL and reference the UDF it returns the data as
expected.

The concern I have is regarding the file access count:  it has the same
number of accesses as there are number of records returned -- but the 
input
parameters to the UDF were the same for each UDF access.

Am I correct that there would be one access to the UDF's table
corresponding to the first "call" and then since each subsequent call has
the same parameter values it shouldn't access the table again?   This is 
on
a V5R2 system.

Bill

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