The SYSCS_UTIL.SYSCS_GET_XPLAIN_MODE function returns the current xplain mode.
If the xplain mode is non-zero, then statements are not actually executed, but are just compiled, and their statistics recorded in the SYSXPLAIN_* database tables. If the xplain mode is zero (the default), then statements are executed normally.
Tuning Java DB contains general information about how to use XPLAIN style and the XPLAIN database tables.
SYSCS_UTIL.SYSCS_GET_XPLAIN_MODE() RETURNS INTEGER
To determine the current value of the XPLAIN mode: