Hello guys,
Just a very quick question ?
I need to do a lookup on an Oracle database, is it worth loading the table into a dataset or not ?
If I'm not wrong, it is no more possible to produce an output link out of an OCI stage that has an input link (except reject) which forces me to create an extra job if I need to load a dataset.
Thank you very much
Lookup on which stage
Moderators: chulett, rschirm, roy
Hi ShaneMuir,ShaneMuir wrote:Have you actually tried?
It is very possible to use an oracle stage directly as a referential input to a lookup.
Yes I have
Just want to know if it takes down performance or not. In other words, is it compulsory to create the datasets to avoid performance drop ?
I heard the wew version creates virtual datasets when lookups on oracle stages occur.
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Unless you are doing a sparse lookup, the data are always loaded into a (virtual) Data Set. You don't have to do anything. This just happens.
Loading into a (physical) Data Set won't change performance at all in the big picture, but may time-shift the cost of loading the data set to an earlier phase of processing. The gain will be slight. A Lookup File Set may be preferable, because that also time-shifts the building of the hash table index on the lookup table (LUT) in memory.
Loading into a (physical) Data Set won't change performance at all in the big picture, but may time-shift the cost of loading the data set to an earlier phase of processing. The gain will be slight. A Lookup File Set may be preferable, because that also time-shifts the building of the hash table index on the lookup table (LUT) in memory.
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Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.
Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.