Ensure when tables are unloaded/reloaded using RC/Migrator that correct utility parameters are used so the process is streamlined
Article ID: 54189
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Issue/Introduction
When tables are unloaded of their data and the database objects rebuilt, the unloaded data must then be reloaded to complete the task.
When RC/Migrator for Db2 for z/OS (RCM) generates analysis output, it must streamline the generated code so that the format in which
the data is unloaded is correctly recognized by the load utility to ensure that the whole process runs smoothly.
Resolution
When producing an analysis of a strategy a user is able to choose a utility model and select combinations of utilities for code generation.
These are combinations of Fast Unload for Db2 for z/OS (PFU), Batch Processor Unload, Fast Load for Db2 for z/OS (PFL) and IBM Load.
These selections are made using RC/Migrator's Utility Model Services prior to the analysis and are stored as a distinct MODEL. Many distinct variations can be created.
Combinations that are valid include:
Fast Unload(FUNLD)/Fast Load(FLOAD)
Fast Unload(FUNLD)/IBM Load(LOAD)
Batch processor Unload(UNLOAD)/IBM Load(LOAD)
IBM Unload(IBMULD)/IBM Load(LOAD)
IBM Unload(IBMULD)/Fast Load(FLOAD)
This combination is not supported:
Batch Processor Unload(UNLOAD)/Fast Load(FLOAD)
This is because the Fast Load model does not support the record format unloaded by Batch Processor Unload as it has special record continuation characters.
If this combination is attempted Model Services generates this message: RO054 RO054E The combination FLOAD and UNLOAD is invalid.
Each utility model has individual elements for each utility type. Each of these contains variables which are automatic or user specified that help to streamline the code that is generated.
Each of the sections below will highlight particular variables which start with "%" that are often part of utility parameters for that particular utility.
Note that the actual utility syntax of IBM's Unload utility and DSNTIAUL application are also not supported by the RCM Models although
Batch Processor Unload and Fast Unload can unload in DSNTIAUL format.
The Unload Utilities
Fast Unload Model Element (FUNLD)
%OUTFORM
This automatic variable is used by model services to determine what type of record format will be produced depending on the type of utility being used at load time.
%OUTFORM is resolved as "DSNTIAUL" or "LOAD" format depending on the needs of the LOAD utility. RC/Migrator is aware of which load utility will be used.
BATCH PROCESSOR UNLOAD(UNLOAD)
%COLUMNS
This variable produces all the correct syntax for each column being unloaded depending on whether there have been changes in the column order
or characteristics and the type of load utility being used.
It's not just a list of columns but a list that is prepared based on how the records will be unloaded.
Fast Unload model element (FUNLD) and Batch processor Unload(UNLOAD)
These two model elements both contain the %LARGE and %SELECT variables.
%LARGE
The variable is a constant value defined in the model by the user that is used to establish the data volume size limit at which the unload dataset(SYSREC) is allocated to either DISK or TAPE. The model has conditional logic which determines if syntax to create a tape or disc dataset is generated based on this value of %LARGE in comparison with the %REORGP value. %REORGP calculates the estimated pages for a tablespace.
This constant value which is set inside the FUNLD and UNLOAD model elements must match the same value to be found in the Load models (LOAD and FLOAD) models.
Warning message RMA742W is displayed if these do not match.
%SELECT
This variable produces a list of selected columns in the correct order which are being unloaded from the source table. This must match with the columns
generated by the %COLUMNS variable during the Load utility.
The LOAD Utilities
Fast Load (FLOAD)
The FLOAD model element contains two automatic variables which help to streamline the generation of the LOAD task.
INPUT-FORMAT %INFORM
The %INFORM automatic variable is used to set the INPUT-FORMAT for FAST LOAD. It is set to SEQ if FAST UNLOAD uses OUTPUT-FORMAT
DSNTIAUL. It is set to UNLOAD if FAST UNLOAD uses OUTPUT-FORMAT LOAD.
OUTPUT-CONTROL %OUTCNTL
The %OUTCNTL automatic symbolic resolves to 'BUILD' or 'ALL' based the value assigned to %OUTFORM by Fast Unload. If %OUTFORM is resolved
to DSNTIAUL, then %OUTCNTL will be resolved to ALL otherwise %OUTCNTL is resolved to BUILD.
IBM LOAD (LOAD)
The LOAD model element contains one automatic variable which helps to streamline the generation of the LOAD task.
%LOADCALL
If the data was unloaded with Batch Processor Unload then it adds in code to look for a continuation char x'FF' at column 72 otherwise it does not look
for any continuation char because the data comes from Fast Unload.
Fast Load (FLOAD) and IBM LOAD (LOAD)
%COLUMNS
This variable produces all the correct syntax for each column being loaded depending on the type of UNLOAD that was produced. This can also vary
depending on whether there have been changes in the column order or characteristics. It's not just a list of columns but a list that is prepared based on
how the records were unloaded.
Additional Information
Information about RC/Migrator Utility Model Services can be found in the RC/Migrator User Guide. Fast Unload , Fast Load and Batch Processor User Guides.
Information about the IBM LOAD Utility can be found in the IBM DB2 Utility Guide and Reference. Information about DSNTIAUL can also be found in
the IBM DB2 Utility Guide and Reference.
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