$ZTNAME

Within a trigger context, $ZTNAME returns the trigger name. Outside a trigger context, $ZTNAME returns an empty string.

$ZTDATA

A fast path alternative to $DATA(@$REFERENCE)#2 for a SET or $DATA(@$REFERENCE) of the node for a KILL update.

$ZTDELIM

Within a SET trigger context, $ZTDE[LIM] returns the piece separator, as specified by -delim in the trigger definition. This allows triggers to extract updated pieces defined in $ZTUPDATE without having the piece separator hard coded into the routine. Outside of a SET trigger context, $ZTDELIM is null.

$ZTLEVEL

Returns the current level of trigger nesting (invocation by an update in trigger code of an additional trigger).

$ZTOLDVAL

Returns the prior (old) value of the node whose update caused the trigger invocation or an empty string if node had no value; refer to $ZTDATA to determine if the node had a data value.

$ZTRIGGEROP

For SET (including MERGE and $INCREMENT() operations), $ZTRIGGEROP returns the value "S". For KILL, $ZTRIGGEROP returns the value "K". For ZKILL or ZWITHDRAW, $ZTRIGGEROP returns the value "ZK". For ZTR, $ZTRIGGEROP returns the value "ZTR"

$ZTSLATE

$ZTSLATE allows you to specify a string that you want to make available in chained or nested triggers invoked for an outermost transaction (when a TSTART takes $TLEVEL from 0 to 1).

$ZTVALUE

For SET, $ZTVALUE has the value assigned to the node which triggered the update. Initially this is the value specified by the explicit (triggering) SET operation. Modifying $ZTVALUE within a trigger modifies the value GT.M eventually assigns to the node.

$ZTUPDATE

For SET commands where the GT.M trigger specifies a piece separator, $ZTUPDATE provides a comma separated list of ordinal piece numbers of pieces that differ between the current values of $ZTOLDVAL and $ZTVALUE.

$ZTWORMHOLE

$ZTWORMHOLE allows you to specify a string up to 128KB that you want to make available during trigger execution. You can use $ZTWORMHOLE to supply application context or process context to your trigger logic. Because $ZTWORMHOLE is retained throughout the duration of the process, you can read/write $ZTWORMHOLE both from inside and outside a trigger. Note that if trigger code does not reference $ZTWORMHOLE, GT.M does not make it available to MUPIP (via the journal files or replication stream). Therefore, if a replicating secondary has different trigger code than the initiating primary (an unusual configuration) and the triggers on the replicating node require information from $ZTWORMHOLE, the triggers on the initiating node must reference $ZTWORMHOLE to ensure GT.M maintains the data it contains for use by the update process on the replicating node. GT.M allows you to change $ZTWORMHOLE within trigger code so that a triggered update can trigger other updates but because of the arbitrary ordering of triggers matching the same node (refer to the discussion on trigger chaining below), such an approach requires careful design and implementation.