Need help with hashfile

Post questions here relative to DataStage Enterprise/PX Edition for such areas as Parallel job design, Parallel datasets, BuildOps, Wrappers, etc.

Moderators: chulett, rschirm, roy

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zulfi123786
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Need help with hashfile

Post by zulfi123786 »

Can any one help me in understanding the two options "Enabled, Lock for Updates" and "Disabled, Lock for Updates" as i did not find the description given in the guide to be friendly.
ArndW
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Post by ArndW »

What is enabled or disabled? For those who aren't at a DataStage client to check, which button or box in which stage are you referring to?
chulett
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Post by chulett »

Pre-load file to memory enabled or disabled, with the added bonus of the record being 'looked up' locked during the process... and the manual seems pretty detailed on how it works to me:
Pre-load file to memory. You can use these options to
improve performance if the output link is a reference input to
a Transformer stage. If you select Enabled, the hashed file is
read into memory when the job is run (Disabled is selected
by default). The remaining two options are for specialist use
and cater for situations where you need to modify a lookup
table as a job runs. If Enabled, Lock for Updates is selected
the hashed file is read into memory when the job is run. If a
lookup is not found in memory, the job looks in the file on
disk, if the lookup is still not found, an update lock is taken
in the knowledge that the record will subsequently be
written in the hashed file by this job. The operation for
Disabled, Lock for Updates is similar, except that the hashed
file is not read into memory.
Which part is... less than friendly? :wink:
-craig

"You can never have too many knives" -- Logan Nine Fingers
ray.wurlod
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Post by ray.wurlod »

Moderator: please move to Server forum
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