SORT - Control of Sort Program

This Natural profile parameter is used to control the sort program used for the processing of SORT statements. It corresponds to the NTSORT macro in the Natural parameter module.

Possible settings For an explanation of the individual sort options, see SORT Parameter Syntax; for their possible settings, see Keyword Subparameters.
Default setting See Keyword Subparameters.
Dynamic specification yes This parameter can only be specified dynamically. In the Natural parameter module, the macro NTSORT is used instead.
Specification within session no  

Notes:

  1. The keyword subparameters of SORT or NTSORT can be used to specify options that control the handling of the sort program to be used when a SORT statement is executed.
  2. The sort program to be used can be either Natural's internal one (the default for all environments) or an external one. The type of sort program used depends on the setting of the keyword subparameter EXT.

The following topics are covered below:

SORT Parameter Syntax

The SORT parameter is specified as follows:

SORT=(keyword-subparameter=value,keyword-subparameter=value,...)

For names and values of the keyword subparameters, see Keyword Subparameters.

NTSORT Macro Syntax

The NTSORT macro is specified as follows: 

         NTSORT EXT=value,                                             *
               EXTEOJ=value,                                           *
               EXTNAME=value,                                          *
               EXTOPT=value,value,...,                                 *
               STORAGE=value,                                          *
               WRKSIZE=value

For names and values of the keyword subparameters, see Keyword Subparameters.

Keyword Subparameters

EXT | EXTEOJ | EXTNAME | EXTOPT | STORAGE | WRKSIZE

EXT - Use of External Sort Program

EXT=value specifies if an external sort program is to be used or not.

Value Explanation
ON An external sort program will be used. The use of an external sort program is possible only in batch environments, including IMS TM/BMP, and TSO.
OFF The Natural sort program will be used.

This is the default value.

Note:
We recommend that you set EXT=ON if your environment supports the use of an external sort program. This avoids the need to adapt WRKSIZE to the amount of data to be sorted.

EXTEOJ - Action in the Event of an Error

EXTEOJ=value specifies the action to be taken if an error is detected during the execution of the external sort program.

Value Explanation
ON If an error is detected, sort processing is terminated. ON requires that the sort program used is able to detect a return code of 16 from both the E15 and E35 sort exit routines.
OFF If an error is detected, Natural withholds further calls to the sort program and ignores each record as it is passed to the E35 sort exit routine (this is the default).

EXTNAME - Name of External Sort Program

EXTNAME=value specifies the name of the external sort program to be used.

Value Explanation
1 to 8 characters. External sort program name.
SORT This is the default value.

EXTOPT - Additional Options for External Sort Program

EXTOPT=(value,value,...) specifies additional options for the external sort program.

Natural generates the necessary field and format parameters and passes them to the external sort program. With EXTOPT, you can specify additional parameters to be passed to the external sort program. You can only specify parameters that are part of the control statement syntax of your external sort program.

You can specify up to two option strings which are delimited by a slash (/). The first option string is appended to the SORT control statement, the second option string is used to build an OPTION control statement. You may omit the option string before or after the slash. If the option string after the slash is omitted no OPTION control statement is generated at all.

The whole option string must be enclosed in single quotes ('...'). For compatibility reasons, it is still possible to have the option string enclosed in brackets instead.

For compatibility reasons, a single option string without a leading or trailing slash is handled differently. Depending on the underlying operating system, the options are appended to the SORT control statement.

Example:

The additional parameters can be specified as in the following example:

EXTOPT=(SIZE=E2000000,NOEQUALS,DYNALLOC=(3350,8))
EXTOPT='SIZE=E2000000,NOEQUALS,DYNALLOC=(3350,8)'
EXTOPT='SIZE=E2000000,NOEQUALS,DYNALLOC=(3350,8)/NOCHECK'
EXTOPT='/NOCHECK'
EXTOPT='WORK=4/'

STORAGE - Type of Storage Medium

STORAGE=value specifies the type of storage medium to be used by Natural's internal sort program if there is not enough storage available in the work pool (WRKSIZE). If the number of records exceeds this storage, the internal sort program tries to use intermediate storage to additionally process records.

Value Explanation
MAIN Only the remaining storage of WRKSIZE is used, no other intermediate storage is available.

This is the default setting.

BP The sort buffer pool is used as intermediate storage.
SD SD files are used as intermediate storage. This value is evaluated under Com-plete only.
SMARTS SMARTS portable file system is used.
SD Files under Com-plete/SMARTS

  • The SD files used for sort processing are allocated as temporary SD files. They are allocated for a stack level. This means, the name syntax of the temporary SD files is: 

    &&STsnnn

    Where:

    && Indicator for a temporary SD file
    ST Standard prefix for the temporary SD file used for sort processing
    s Stack level
    nnn Sequence number within a single sort run

  • SMARTS work files are located in the SMARTS Portable File System. The directory path must be specified with the SMARTS environment variable $NAT_WORK_ROOT. For a SMARTS work file used for sort processing, a SORT directory is created with subdirectories for each user who performed a sort: $NAT_WORK_ROOT/SORT/userid. The name of the work file used for sort processing corresponds to the name of the temporary SD file under Com-plete.

Usage of Sort Buffer Pool

  • The use of a sort buffer pool only makes sense if you cannot further increase the WRKSIZE to hold the sort records. This typically applies in online environments with a storage thread of limited size. In all other cases, you only need to specify a sufficient WRKSIZE.

  • If you want to use a sort buffer pool, define the SORT keyword subparameter STORAGE=BP to indicate that a sort buffer pool is to be used for any additional storage beyond the defined WRKSIZE. Simultaneously, use the profile parameter BPI or the parameter macro NTBPI to make a buffer pool of TYPE=SORT and NAME=name known to Natural, for example: BPI=(TYPE=SORT,NAME=XYZ). When a name is specified with the BPI keyword subparameter NAME, reference is made to a global sort buffer pool, whereas a local sort buffer pool can be specified by NAME=' ' (blank).

WRKSIZE - Size of Work Buffer Used by Sort Program

WRKSIZE=value specifies the size of the work buffer used by the sort program.

The work buffer specified by WRKSIZE accommodates internal sort control data. The remaining storage is used to collect and sort the records. The size of the sort control data depends on various factors (the WRKSIZE itself, the sort record length, the number of sort keys, their size and format) and can therefore not be calculated in a formal way.

Value Explanation
0 or 10 - 2097151 Size of work buffer (in KB).

WRKSIZE=0 means that no sort operations can be performed.

10 This is the default value.

Note:

Examples of SORT Parameter

Example 1:

SORT=(EXT=OFF,WRKSIZE=1024)

The internal Natural sort program and a work buffer of 1 MB are used for sort processing.

Example 2:

SORT=(EXT=ON,EXTOPT='/EQUALS')

An external sort program with an OPTION EQUALS control statement is used for sort processing.

Examples of NTSORT Macros

         NTSORT EXT=OFF,                                               *
               WRKSIZE=1024

         NTSORT EXT=ON,                                                *
               EXTOPT='/EQUALS'

The first example defines an internal Natural sort program and a work buffer of 1 MB. The second example defines an external sort program with an OPTION EQUALS control statement.