MSRES parameter
Maximum SREs per file in RETBL
Summary
- Default value
- 0
- Parameter type
- System
- Where set
- On User 0's parameter line or reset by system manager
- Related products
- All
- Introduced
- Model 204 V5.1
Description
The MSRES parameter controls how entries are stored in the Record Enqueuing Table for transaction backout (TBO) pending updates. When MSRES is set to 0, TBO pending update entries are stored as record set entries. These may use less storage space in the Record Enqueuing Table.
If MSRES is set to a nonzero value, that value is the maximum number of TBO pending updates per file that will be stored as Single Record Entries (SREs). When a file requires more than MSRES SREs, all SREs are converted to record set entries.
A nonzero MSRES may require a larger Record Enqueueing Table, but the CPU cost of reading the entries may be reduced when they are SREs. The amount of additional space and the level of performance improvement are application dependent.
Usage
In a small number of cases, setting the MSRES parameter may require a larger record enqueuing table than with the default MSRES=0. If you get the following message:
M204.1219 RECORD LOCKING TABLE FULL
then either increase the size of the record enqueuing table by increasing LRETBL, or specify MSRES=0. This only needs to be done for the Model 204 job in which you are experiencing the record locking table full condition, not in all jobs.
- For single-user jobs, leave MSRES at the default value of 0.
- For multi-user jobs, Rocket Software recommends setting MSRES to a low, nonzero value, perhaps 32, adjusting LRETBL, if required.