+DEGREE
Direct access is in effect
Direct access is in effect if you have specified any of the following options:
- On the UNLOAD command:
- DIRECT YES
- DIRECT AUTO and BMC AMI Unload has not encountered any conditions that cause it to switch to DIRECT NO.
- On the UNLD command:
- MODE(DIRECT)
- MODE(AUTO) and BMC AMI Unload has not encountered any conditions that cause it to switch to MODE(DB2SQL)
The value of the integer variable has the following meaning:
Value | Description |
|---|---|
0 | This is the default value. |
2 through 63 | BMC AMI Unload performs the specified number of parallel operations. |
0 or 1 | BMC AMI Unload reads the TS for each unload. |
You can use the +DEGREE parameter subject to the following conditions and restrictions:
- You cannot specify ORDER BY. For more information, see ORDER-BY or UNLD-ORDER-BY.
- You cannot specify BYPART. For more information, see BYPART or UNLD-BYPART.
- You cannot specify partitioned numbers.
- You cannot unload from an image copy.
- Each unload statement must unload to a different unload data set.
- You cannot mix dirty unload and online unload.
- All unloads must be to either statically allocated unload data sets or dynamically allocated data sets, but not to a mix of both.
- The size of all merged unload statements to be processed in parallel cannot exceed 63 KB. If the size exceeds 63 KB, BMC AMI Unload processes the first 63 KB in parallel and then the remainder in parallel.
Specify one of the following actions:
- (recommended) Unload to DASD.
- You can unload to a VTS if you override MEDIA=D in the XULDDYNM automation control point for this job. To unload to tape also specify FSEQ=1 in XULDDYNM to prevent stacking and specify DDNCOUNT(n) in OUTPUT or NGTTAPE to allocate n tape drives to match +DEGREE(n).
Attempts to stack data sets on VTS or tape result in an error.
Successive statements that satisfy these conditions form a parallel output group. If a statement does not satisfy these conditions, the existing group ends and another group starts. BMC AMI Unload dispatches multiple groups simultaneously depending on the MAXTASKS parameter value.
The BMC AMI Unload reader can read a maximum of 32 partitions concurrently and process up to 63 output data sets in parallel. However, you cannot stack two output data sets in a single group on the same tape.
Parallel operations have the following advantages and disadvantages:
Advantages:
- Reduced elapsed time and elapsed connection time
- Reduced memory utilization
- Reduced the number of EXCP counts
Disadvantages:
- Reduced zIIP OFFLOAD and as a result, significantly increased CPU time
When you combine two statements, BMC AMI Unload issues a message such as the following message (during parse):
BMC AMI Unload issues a message such as the following message before starting work: