Adaptation of JCL to large databases
The procedures used for the migration contain default settings that should be changed depending on the volume of the database to migrate.
These parameters (such as SPAOT or SPAGY) define the size of temporary files, output files or sort files.
The following tables contain the correspondence between the number of records or entities of a database in the current session and the size to specify in the parameters of procedures for large-volume files.
The database restoration report (PAC7EU) gives an estimate of the number of records to take into account to calculate the size of large files (parameters in migration procedures).
The LOGICAL number of DATA FILE is significant and can be used as reference records number.
This number of records corresponds to the parameter N used in the following calculation rules.
1. MIBR procedure
1.1. Assignment
DDNAME | Number of tracks for N records | Assignment parameters |
---|---|---|
&&GY | N / 130 | &SPAGY |
&&PACXWD | N / 110 | &SPATD |
&OUTFILE (TA2) | N / 185 | &SPAOT |
The following table shows the step where these files are used, in the order of the steps in the MIBR procedure.
These files are temporary and are deleted after the last step where they are used, except &OUTFILE, which contains the TA2 file.
DDNAME | PACX2 | PACS96 | PATI 7 | PACS91 | PACS98 |
---|---|---|---|---|---|
&&PAC7AT | X | X | |||
&&GY | X | X | |||
&&PAC7TA | X | X | |||
&&PAC7TI | X | X | |||
&&PACXWD | X | ||||
&OUTFILE (TA2) | X |
1.2 Sort files
It is recommended to assign 2000 CYL by million records, distributed evenly on the various sort files.
2. Procedures MIA1, MIA2, MIA3, and MIA4
Procedure / DDNAME | Number of tracks depending on the number of entities | Assignment parameters |
---|---|---|
&OUTFIL2 | n * 3 | &SPAOT |
&OUTFILE | n * 6 | &SPAOU |