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CRITICAL.POINT (CP)
For files being written at the last Critical Point, Report Recovery will automatically restart
writing the Report from the record written at the last Critical Point. For files being read at
the last Critical Point, Report Recovery will restart reading at the beginning of the file. If
you find that this is not what you require, you must save the current record number,
GLB.RECORDx, in the Critical Point data block and restore the value of GLB.RECORDx if
the Report is restarted.
Where to include Critical Points
The CRITICAL.POINT; command should be used at important points in the processing
cycle of the Report, such as after a record is read, but before it is written. This means that
data stored for recovery is the data about to be processed.
For an MCP based LINC System, regular Critical Points should be included to avoid delays
at sync points and control points, when other programs using the database may be
suspended waiting for this Report.
For a UNIX based LINC System, regular Critical Points should be included to avoid delays
in committing the locked records, when other programs using this database may be
suspended waiting for this Report.
OLTP
Use of this command with OLTP is described in your LINC Generate Operations Guide.
Critical Points in Reports Using ROC
Standard ROC Reports write output to the ROC tables in the LINC Database. For MCP and
OS 2200 based LINC Systems, if the database is not in transaction state when data has to
be written to a ROC data structure, a transaction state will be started for the database
update, and then immediately end. For a UNIX LINC System, the database will stay in
transaction state until a Critical Point.
ROC database activity does not affect user database activity, and so CRITICAL.POINT;
commands (or SLEEP; commands) are not required to avoid long database transactions
due to ROC database activity.
At a Critical Point, all output for a Report is written to the database so that it may be
recovered. On resumption of the Report, output continues to the same database files. The
current files are not released.
On recovery, the System Data items GLB.FORMDEPTH, GLB.PITCH, GLB.LINECOUNT,
GLB.PAGECOUNT, and GLB.STN are returned to their current values as at the last
CRITICAL.POINT. All other System Data items are set to the values held at the time of first
output to the current print file.
Note: ROC is not available with LDA.
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