The valid code combinations in the checkpoint template file are shown here:

B    [S,R,E,J,U] [T,D,E] [T,D,E,A]
P    [S,R] [T,D] [D,T]
W    [S,R,E,J,U,D,C] [T,D,E] [T,D,E,A]
I     [,R,E] [T,D,E] [T,E]
F    [,R,E] [T,D,E] [T,E]
E    [S,E] [T,D] [D,T,E]

For every entry with a first character of B, there must be an accompanying entry beginning with E.

This section demonstrates how the codes are used in the checkpoint template file to perform checkpointing and roll forward operations in a variety of ways.

The checkpointing operation (ckpdb command) executes the following sequence of codes in the cktmpl.def file:

Bsxy   Beginning checkpoint
Wsxy  Executed once for each location
Esxy  Ending checkpoint

where:

x denotes D for disk, T for tape, or E for both.
y denotes D for database, T for table, or E for both.

The roll forward operation (rollforwarddb command) processes the following codes in the cktmpl.file:

WCxA for each location

If table processing is specified, the following codes are executed:

BRxT   once per location
IRxT    once per location
WDxT   for each table
WRxT   for each table
FRxT   once per location
EExE  once (note that ERxT is executed if available)

If an entire database is being recovered (rather than specific tables), the following codes are executed:

BRxD   once for each location
WDxD   once for each location
WRxD   once for each location
EExE   once (note that ERxD is executed if available)

For all roll forward operations, the following codes are executed:

BUxA    if dumps are to be applied
WUxA
EExE
BJxA    if journals are to be applied
WJxA
EExE