Data Transformation Engine Map Designer Reference Guide

Chapter 5 - Card Settings SourceRule Input Card Settings
Map Designer Reference Guide
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Guidelines for Reusing Work Areas
Use the following guidelines when defining whether to reuse workareas. The
WorkArea card setting depends upon the map setting for WorkSpace >
Location and PageSize and PageCount settings.
♦ WorkSpace > Location setting. If the map setting for WorkSpace is File,
the input card’s work area can be reused. If the map setting for WorkSpace is
Memory, the input card’s work area can be reused only when the map is
initiated using the RUN function. It cannot be reused from an API.
♦ WorkSpace > PageSize and PageCount settings. When reusing work files,
the paging configuration (page size and number of pages) for the first
execution and subsequent executions of the map must be the same.
For example, if the first execution (when the work files are created) uses a paging
configuration of eight pages of 64K each, the subsequent executions (where the
work files are reused) must use the same paging settings, in this case eight pages
of 64K each.
♦ For One Map Only. The WorkArea card setting applies to a given map only.
For example, it does not apply to two different maps that using the same input.
♦ FetchAs = Integral. When a map is executed and the input card FetchAs =
Integral, the work area is automatically reused for each burst. If WorkArea
= Reuse, that work area is saved on completion of the map execution.
♦ FetchAs = Burst. When the input card has a FetchAs of Burst, a new work
area is created for each burst. If WorkArea = Reuse, the last work area is
saved on completion of the map execution.
FetchAs > FetchUnit
The FetchUnit setting only applies to input cards. The FetchUnit setting defines
the number of units of data to retrieve each time a request for data is made to the
adapter. FetchUnit is primarily used when the FetchAs setting is set to Burst
although it may also be used in other situations. The default value for FetchUnit
is S (unspecified all).
A specific FetchUnit value allows you to aggregate, or "batch", a set of physical
units (such as messages on a queue) into a logical unit of work. The unit of data is
adapter-specific.