Description of the fixed segment
The fixed segment can optionally be followed by a variable length extension area and a variable number of database trailers. The extension area has optional data, which is described in the TRNEXTEN element.
BMC recommends that any OEM or user program that processes the transaction log records use the TRNDBTOF element to locate the start of the database trailers segment and the TRNEXTEN element to locate the start of the extension area.
The TRNDBTOF and TRNEXTEN elements have the offsets to the first trailer and the extension area. Using these offset fields to locate these segments isolates OEM or user programs from changes in the length of the fixed area, within a release, and from release to release.
The extension area can also be accessed by using the $TRNEXT macro, which is distributed in BBSAMP. The macro locates the start of any data section in the extension. Using this macro isolates user or OEM programs from changes in the extension.
Record-format-fixed-segment describes the fixed segment of the transaction log record.