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Posted: Tue Jan 25, 2011 6:30 pm
by ray.wurlod
That design operates as two jobs, even though it's one. For a sufficiently small reference data set the hashed file write cache and read cache can be used, so that lookups are performed in memory, which should be faster than performing them to disk.
Posted: Tue Jan 25, 2011 7:00 pm
by chulett
Ray, Smay. Phooey.
Posted: Tue Jan 25, 2011 7:05 pm
by mavrick21
Craig & Ray,
You guys are awesome! :D
Thanks
Posted: Fri Feb 04, 2011 3:06 pm
by mavrick21
I was about to ask - Can data in Hashed file be cleared without deleting DATA.30, OVER.30 and the VOC entry?
And I found out I can
DELETE FROM <HASHED FILE>
Posted here hoping this might be useful for others
Posted: Fri Feb 04, 2011 4:01 pm
by chulett
Only if there is a VOC entry for the hashed file, from what I recall. That is, only if it is in an 'account' rather than a 'directory', that or you've manually created one for it using the SET.FILE command.
There's also a 'Clear' option if you need to do that inside a job in the Hashed File stage but I'm sure you knew that.
Posted: Fri Feb 04, 2011 4:31 pm
by mavrick21
Craig,
In that job the hashed file was used as reference and I couldn't find the job which populated it. Didn't want to waste my time creating a new job to clear it
Posted: Fri Feb 04, 2011 4:52 pm
by ray.wurlod
mavrick21 wrote:I couldn't find the job which populated it.
Why not? Did you attempt a "where used" analysis" on the table definition for the hashed file?
Posted: Fri Feb 04, 2011 5:06 pm
by mavrick21
Ray,
Is "where used" analysis available on DataStage 7.5? If so where can I find it?
Thanks
Posted: Fri Feb 04, 2011 7:04 pm
by chulett
Manager. The icon looks like a chemistry beaker from what I recall.
Posted: Fri Feb 04, 2011 7:06 pm
by chulett
mavrick21 wrote:In that job the hashed file was used as reference and I couldn't find the job which populated it. Didn't want to waste my time creating a new job to clear it
Well, I've seen plenty of places that have jobs that do just that.
Posted: Fri Feb 04, 2011 7:43 pm
by mavrick21
Craig,
We follow the same. One Clear_Hash job for ever Server job
Posted: Sat Feb 05, 2011 12:19 am
by ray.wurlod
mavrick21 wrote:I was about to ask - Can data in Hashed file be cleared without deleting DATA.30, OVER.30 and the VOC entry?
And I found out I can
DELETE FROM <HASHED FILE>
Posted here hoping this might be useful for others
is way more efficient.
Posted: Tue Feb 22, 2011 10:25 am
by mavrick21
Hello,
Below is the LIST.DICT of HASHED_STORE_DEL
Code: Select all
Type &
Field......... Field. Field........ Conversion.. Column......... Output Depth &
Name.......... Number Definition... Code........ Heading........ Format Assoc..
@ID D 0 HASHED_STORE_DE 10L S
L
Jobname D 0 Jobname 10L S
CURR_DEL D 1 CURR_DEL 10L S
@KEY PH Jobname
@ PH Jobname
CURR_DEL
ID.SUP
5 records listed.
Below is a sample entry in the hashed file.
Code: Select all
Jobname... CURR_DEL..
SFCO_CS9_E
PM9
J_Stage_PS E
_VAR_DATA_
SFPA_CS9_E
PM9
265 records listed.
>
>COUNT HASHED_STORE_DEL
265 records counted.
My question- Can I manually insert a record into the hashed file? If so what's the syntax?
Thanks.
Posted: Sat May 28, 2011 12:01 am
by mavrick21
Hello Gurus,
When data is stored in Hashed files, is it indexed on key fields and stored?
Thanks
Posted: Sat May 28, 2011 12:18 am
by chulett
A hash value is computed for the key fields (thus the name) and that is used to store the value. I seem to recall a Ken Bland post here with all kinds of gory details about hashed files... and I'm sure Ray has a thing or two up his sleeve.