Page 1 of 1

Index Sequential File?

Posted: Tue Aug 08, 2006 7:42 pm
by chowmunyee
Hi,

Is there anyone heard index sequential file before? i searched on the net and manual but i couldnt found out for this....

This is the client told me that sequential file categorized into 2.
normal sequential file.
indexed sequential file.

Due to my data is more than 6 millions records....is it suitable to use sequential file?

Thank you

Posted: Tue Aug 08, 2006 8:09 pm
by kcbland
DataStage does not have anything like this, it doesn't read or write these. The Sequential stage is a traditional sequential textfile reader/writer.

A quick google found this for your reading pleasure:
http://www.theteacher99.btinternet.co.u ... p5_7_1.htm

Posted: Tue Aug 08, 2006 8:24 pm
by chowmunyee
kcbland wrote:DataStage does not have anything like this, it doesn't read or write these. The Sequential stage is a traditional sequential textfile reader/writer.

A quick google found this for your reading pleasure:
http://www.theteacher99.btinternet.co.u ... p5_7_1.htm
Yeah i have search this web site also while im using the google....but when i typed " index sequential file datastage " in search engine....it doesnt display any result which im searching on....

Thank you kcbland...

Posted: Tue Aug 08, 2006 10:29 pm
by loveojha2
Due to my data is more than 6 millions records....is it suitable to use sequential file?
Sequential files are best suited if the processing requirement requires every record to be processed.

Whereas Index Files (including the Hashed indexed ones) are suitable where requirement is faster random processing.

So in all I don't think that there could be any problem with using the Sequential file.

Posted: Tue Aug 08, 2006 10:39 pm
by ray.wurlod
Try searching (both here and Google) for "indexed sequential" and "ISAM" (indexed sequential access method). It's more of a mainframe than a server technology.

Posted: Sun Aug 13, 2006 6:04 am
by kumar_s
Just got to know, propriety database of Hyperion Enterprise application use flat file to store its data. And its is possible to fetch the chunk of data, like for particular period, or for particular account.
Not sure, if it sorts data before it loads in.

Posted: Sun Aug 13, 2006 7:43 am
by chulett
I don't believe so. I've never been directly involved with mainframes but was exposed to Index Sequential files back in the 80's. Spend a goodly number of years working for a Texas Instruments VAR and their 990 'minis' (which interestingly enough ran an OS called 'DX10') supported these - aka ISAM files. I also recall working with 'Relative Record' files but don't recall the gory details of those.

I visited the TI plant in Austin in the summer (primary memory: HOT! AC 24x7) and picked up a TI calculator that I still have and use. I needed it because it supported Hex and Octal math, which was hard to find then. We were under the covers of the OS quite a lot, poking around with what was basically a hex editor, 'fixing' things... and none of it supported decimal. :lol:

Posted: Thu Aug 17, 2006 4:45 am
by kumar_s
Discussion on Hyperion flat file database can be found here.
http://businessintelligence.ittoolbox.c ... ice-487889

Re: Index Sequential File?

Posted: Thu Aug 17, 2006 5:01 am
by ArndW
chowmunyee wrote:...Is there anyone heard index sequential file before?...
This would be an ISAM file - take a google on that and you'll get lots of hits.