The Syncsort™ MFX Programmers Guide is a reference manual designed for applications programmers who are using Syncsort™ MFX to sort, merge, or copy sequential data sets. This manual is self-contained and assumes only a basic working knowledge of the operating system and its job control language. It should not be necessary to refer to any other manual to produce an efficient sort.
MFX Control Statements describes how to specify and use the ALTSEQ, DUPKEYS, END, INCLUDE/OMIT, INREC/OUTREC, JOIN, JOINKEYS, MODS, OUTFIL, RECORD, REFORMAT, SORT/MERGE, and SUM statements. The discussion of a particular control statement includes these topics: the statement’s syntax format, the versatility provided by the various parameters (many of which are unique to MFX), and the interaction between the control statement and other statements.
How to Use MFX’s Data Utility Features explains and illustrates the Data Utility and SortWriter features through a series of sample applications. Each application is self-contained and provides instructions for specifying both the required JCL and the appropriate control statements.
JCL and Sample JCL/Control Statement Streams analyzes MFX’s job control requirements and describes the MFX DD statements, each of which is illustrated with an example. JCL and control statement streams for MAXSORT and PARASORT are also described. Numerous examples are provided.
PARM Options describes the operational parameters of MFX and identifies the delivered defaults. This chapter explains how to specify such features as dynamic allocation of SORTWK space under z/OS, automatic secondary allocation and release of SORTWK space, the ability to skip a certain number of records or stop after sorting a certain number of records, and message routing.
Invoking MFX from a Program describes MFX invocation through assembler programs using 24-bit, 31-bit, and 64-bit parameter lists. Numerous examples are provided.
The Coding and Use of Exit Programs indicates at which points during sort processing user-written exit routines can be executed. Each exit point is fully documented together with the appropriate tasks. Examples of COBOL E15 and E35 exit routines for fixed and variable-length records are included.
The Flow of the Sort provides a skeletal view of the flow of control in the standard Disk Sort (including the incore sort), merge and copy. This chapter indicates the order in which the control statements and exit routines are processed, information which is particularly useful at the design stage of an application.
MAXSORT explains when MAXSORT should be used, describes its JCL requirements, control statements and PARM options, and provide examples. The chapter also examines MAXSORT’s restart capability and its operator interface.
PARASORT explains the elapsed time advantages of the technique, the type of applications where it can be applied, and the JCL requirements.
MFX DB2 Query Support explains how MFX can improve performance by allowing DB2 data to be passed directly into a SORT or COPY operation without the use of setup steps or user-written E15 exits.
Multiple Input Files explains how to specify multiple VSAM and non-VSAM data sets as input to MFX with the MULTIIN facility. The MULTIIN facility can be used for a SORT or COPY application.
The Dictionary Feature describes how to create symbolic dictionary names for fields, constants and output columns, and use those dictionary names in MFX control statements.
Performance Considerations describes how to design the most efficient application. It contrasts the merits of Disk Sort, PARASORT, and MAXSORT, JCL and invoked sorts, the incore sort, and standard SORTWK techniques. Formulas for calculating main storage and SORTWK requirements are provided. Other topics include the efficient use of control statements and PARMs, tuning main storage and SORTWK allocations and the use of the Checkpoint-Restart feature.
The HISTOGRM Utility Program describes how to use the HISTOGRM program to report on the composition of variable-length files. This program indicates the average record length, byte total, record total, block count and record count. Job control requirements, control statements and messages are outlined. Sample job streams illustrate how to run HISTOGRM as a separate job and as an E15 exit during a variable-length sort.
Value-Added Products describes Syncsort PROCSort – An Accelerator for SAS® Sorting, Syncsort PipeSort, and Syncsort ZPSaver technologies. This chapter also provides detailed information regarding their functions and special features.
Messages documents all of the WERnnnx messages generated by the Syncsort MFX program.
Diagnostics and Technical Support includes sections describing “Troubleshooting Abends” and “Before Calling Precisely Support”.