convert FB record structure with VARCHAR to VB file.

ramsri · Active User Joined: 18 Oct 2008 Posts: 380 Location: India

Hi,

We have a FB file with a length 21167 and would like to convert it to a VB file to save DASD space. Below given is the record structure:

Gnanas N · Posted: Mon Oct 08, 2012 9:36 pm

Hi Ramsri,

How is this FB data set created? Unload of DB2 table?

ramsri · Active User Joined: 18 Oct 2008 Posts: 380 Location: India

Hi,

Output FB dataset is created through program.

Thanks.

Akatsukami · Posted: Mon Oct 08, 2012 9:51 pm

So presumably this program moves the VARCHAR column to a fixed-length character field and writes a fixed-length record. Have you considered changing the program to use variable-length fields and records?

Gnanas N · Posted: Mon Oct 08, 2012 10:04 pm

Is it possible to change the program to create VB data set instead of FB one?

In General,

Nic Clouston · Posted: Mon Oct 08, 2012 10:43 pm

Whilst you are going about all this rearrange your structure so that the varchar field is the last field. You will have to recompile any program that uses that copybook (which you would have to do anyway as you are changing from FB to VB)

I assume you are wanting a SYNCSORT solution for this requirement otherwise you would have posted in one of the language sections or the DFSort section.

ramsri · Active User Joined: 18 Oct 2008 Posts: 380 Location: India

Hi, Program can't be touched (external system). We get the file and want to save DASD space on our side. Yes.....we use Syncsort and looking to convert it from FB to VB.

Thanks.

gcicchet · Posted: Tue Oct 09, 2012 2:20 pm

Hi,

like Nic says, you will need to change all programs that currently read the FB file after converting the file to VB, a lot of work just to save some space.

Gerry

Bill Woodger · Posted: Tue Oct 09, 2012 5:08 pm

Saving 19k per record is probably noticeable. It'd allow you to get more than two records per track :-)

Ramsri,

Note Nic's point about the fields after your VARCHAR. They need to be relocated.

What is your VARCHAR "padded" with? Does it actually contain the length in the first two bytes?

ramsri · Active User Joined: 18 Oct 2008 Posts: 380 Location: India

Bill, this is not a program from our system......we don't own it. we just get the file and create a backup. We find that its occupying too much of space even though it does not utilize all VARCHAR(21000) but hardly 1900 or 2000 of it.

Thanks.

Bill Woodger · Posted: Tue Oct 09, 2012 6:07 pm

Err... I know all that.

If you want to make the record variable you have the easy way, which is to relocate you variable-length part to the "end" of the record. Or the difficult way, which is to plonk the variable-length part somewhere in the "middle" of the record and jump through hoops to find all the fields later.

You explained you can't change the program, and I've not suggested you need to. It is simple. At the same time as you make the record variable, you move the necessary fields.

FTOV, VLTRIM with whatever it is that you are keeping to yourself that is padding the VARCHAR.

daveporcelan · Posted: Tue Oct 09, 2012 6:15 pm

You can use Syncsort to rearrange the fields and backup the data.

You can change to VB at that time.

Use Sycnsort to restore the data back to original format when/if needed.

ramsri · Active User Joined: 18 Oct 2008 Posts: 380 Location: India

The VARCHAR (21000) content from file shows its length in binary format in output file........does it help anyway to create a VB from FB file. We can't rearrange the fields to move varchar to end of file.

Thanks.

daveporcelan · Posted: Tue Oct 09, 2012 6:23 pm

Bill Woodger · Posted: Tue Oct 09, 2012 6:29 pm

enrico-sorichetti · Posted: Tue Oct 09, 2012 6:30 pm

if You simply want to create a backup
use DFDSS, it has quite a good compression factor!

ramsri · Active User Joined: 18 Oct 2008 Posts: 380 Location: India

Bill, no....I am not knocking back the suggestions

I thought the rearrangement might confuse the appl. programmer when one wants to bring the data from backup and use it as input somewhere. I think some kind of notes in backup JCL should be written.

Is this solution work on big/large files? The file always contains records anywhere between 300,000 to 450,000.

Please suggest the solution you offered.

Thanks.

enrico-sorichetti · Posted: Tue Oct 09, 2012 6:52 pm

Bill Woodger · Posted: Tue Oct 09, 2012 7:03 pm

Sorry Ramsri, I missed the "I just want to create a backup" whilst I was being "all-knowing" :-)

Leave the file alone. Look at what enrico posted. If you change the file, it mightn't count as much of a backup, and would only save a couple of extra bytes over enrico's suggestion.

Edit: And even those couple of bytes might be "lost" to other compression possibilities in the record. Why didn't you say up front you just wanted a backup?

ramsri · Active User Joined: 18 Oct 2008 Posts: 380 Location: India

Enrico, I see few of our jobs use PGM=ADRDSSU but write to UNIT=TAPE. Can I write to a tape instead of DASD? Does writing to tape saves space too?

Thanks.

Bill Woodger · Posted: Tue Oct 09, 2012 7:28 pm

If some jobs at your site are using UNIT=TAPE then there may be nothing to stop you also doing that. It is a good medium for backup. Saves a lot of DASD. Why don't you talk to your Production Control/Storage Management people and explain what you have, and then you'll get to do it the way they want you to do it, which is something we can't possibly know.

dick scherrer · Posted: Tue Oct 09, 2012 7:41 pm

Hello,