Adabas logical file extents

I want to limit the logical file extents in our DEVELOPMENT and our ACCEPTANCE Databases. Much the way it was before ADABAS 8.

Want to know how it can be done.



Just a thought, but you could set the NOACEXTENSION option to prevent the file from growing too big.

I am not sure I understand. You would prefer to have a file fill up and get an Adabas response code 75 than to have it go into a 6th, 7th… extent?

You can still monitor for files in n+ extents and plan reorders and always had to be done in version 7.4 and below. :evil:

I am relatively new to the ADABAS world and want/need to understand if having 4 extents for a mainframe ADABAS 7.4 file is leading me down the road to trouble. When I list files with crit. no. of extents in SYSAOS I see I have 4 such files. I have been under the impression that doom is not pending with these files but my lack of experience prevents me from having the confidence in my assessment.

Thank you for any input,
Michael E.

You need a sense of how quickly records are being added to those four files.

  • How much free space is available in the file’s current allocation?
  • Based on average compressed record length, how many more records can be added before you go to a fifth extent?
  • Based on history, how long until you go to a fifth extent?
  • The fifth extent will be allocated as half the file’s current space allocation, if possible. Does the database have enough free space for the fifth extent?
  • If Adabas can’t allocate 50% more space, he will take what he can, possible exhausting free space, leaving none for the next file to go to five extents.

If you upgrade to a v8+ Adabas database, the extents constraints are lifted.

For v7.4 and below, yes, the maximum extents is 5 for any type of database container or file area. Once the fifth extent is allocated and more space is needed, your file will be almost unusable.

Douglas & Ralph,

Thank you for the information. I will put together a plan to reduce the extents in each of the 4 files in question.

Michael E.
P.S. I’ll be back with any questions!