change size of two fields without increasing size of file

[Jean-Pierre A. Radley]

Dennis Malen propounded (on Wed, Sep 09, 2009 at 07:06:55PM -0400):

< top-posting reverted >

| From: "Jean-Pierre A. Radley" <appl at jpr.com>
| > Dennis Malen propounded (on Wed, Sep 09, 2009 at 12:04:36PM -0400):
| > | Assume the following:
| > |
| > | Field 7 is 20 digits.
| > | Field 86 is 6 digits.
| > |
| > | I want to add 5 digits to field 7 and reduce field 86 to 1 digit.
| > |
| > | Can I go in and change the size and let it rip? Will all the other 
| > fields
| > | remain intact?
| >
| > Dennis, do you ever try anything for yourself before asking us about it?
| >
| > Clone the whole file and make the change on one of the copies.
| >
| > Or create a test file with, say, three fields, one of length 20, another
| > of length 6, and a third of any old length, populated by maybe five
| > records, and see what happens.
| >
| > While you're at it, change the edits as well as the lengths and look at
| > what ensues.
| >
| > It should all be quite clear when you're done.
| >
| I have been doing this long enough not to rely on a small sampling to test 
| and rely upon my hypothesis.
| 
| That's what the list is for. Since this is a large and important file I 
| would find it most prudent to ask the list.
| 
| You may choose to be more cavalier. Certainly that is your prerogative. I 
| chose to make sure the odds are as much in my favor as possible.
| 
| Your suggestions are noted and appreciated.

Why would you suspect that restructuring would depend on the size of the
file?

It is far more prudent to have a good backup, or two good backups, than
to trust this or any other list, however fabluous a list may happen to be.

-- 
JP