-----gs_guc_reload(GUC)   set default value of lockwait_timeout by gs_guc reload
--set new value
\! @abs_bindir@/gs_guc reload -D @abs_srcdir@/tmp_check/datanode1/ -c "lockwait_timeout=1s"
\! sleep 3s
show lockwait_timeout;
--no assign value
\! @abs_bindir@/gs_guc reload -D @abs_srcdir@/tmp_check/datanode1/ -c "lockwait_timeout"
\! sleep 3s
show lockwait_timeout;