Sequence of searched segments
When you specify the NEXT, FIRST, or ALL parameter with the FIND or CHANGE primary commands, FM/IMS searches in a forward direction from the first segment within the search range toward the last. In a forward direction, the FIND and CHANGE primary commands read the latest data from the database.
When you specify the PREV parameter with the FIND or CHANGE primary commands, FM/IMS searches in a backward direction from the last segment within the search range toward the first.
Note: When you specify the PREV parameter, it restricts the search range
to those segments between the top of the sliding window and the
segment at the cursor position. The reason fo this is that IMS does
not support reads in the backward direction, so FM/IMS mimics the
backward search by examining segment locations that were stored in
the sliding window as a result of your navigation actions.
As a result, when you use the FIND or CHANGE primary commands in a backward direction
FM/IMS may use segment information that is outdated and different from
the actual database.
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