What does RDW mean

picus_mf · New User Joined: 09 Jun 2006 Posts: 18

Hello,

Can any one give explanation why extra 4 bytes for variable record length and what does '4 byte BDW/RDWs' mean?

enrico-sorichetti · Posted: Wed Jul 09, 2008 5:18 pm Post subject: Reply to: What does RDW mean

they are ...
BDW Block Descriptior Word
RDW Record Description Word
the term sounds a bit funny because only the first halford is used..
both BDW and RDW are usually referred to as having the format "LLbb"
2 bytes for the length and two blank bytes

Robert Sample · Posted: Wed Jul 09, 2008 5:21 pm Post subject:

BDW -- Block Descriptor Word
RDW -- Record Descriptor Word

The length of a variable length record needs to be specified somehow. On the mainframe the RDW holds the length of the variable length record in the first 2 bytes; the last 2 bytes are reserved. The BDW holds the length of the block in the first 2 bytes and again the last 2 bytes are reserved.

ofer71 · Posted: Wed Jul 09, 2008 5:23 pm Post subject:

It's all in the fine manual.

O.