The following question appeared on the Oracle Forums recently:
The use of functions – a function with other selects (eg. calculate availability of a part) – is slowing down our system when we do a select over our product file.
Is there some kind of rule when functions should be used or when we should try to create a more complex – combined – SQL that does not use the function.
Can functions be used in the where clause without loosing a lot of speed?
It’s a really good question, because it prompts such a lot of ideas that need to be tied together, so I thought I’d jot down a few thoughts.
