When does db.lck take effect

I find an expression in my configuration.

AWpMapStAsoClBo = if(LXCpAsoCluTx == position([ascc].[ascl]), TRUE, FALSE)

AWpMapStAsoClBo is FNHBI

$ printMeasureInfo -d . -measure AWpMapStAsoClBo -fnhbi -baseint

True

asclclssstr_mnth

LXCpAsoCluTx is HBI

$ printMeasureInfo -d . -measure LXCpAsoCluTx -baseint -hbi -db

/rpas/sbx/na/domains/liasghcom/LIA/data/asoclu

True

clssstr_mnth

I thought when I ran the expression on different local domains at the same time, there should have reported a db.lck failure. But it didn't. Both mace utility ended successfully.

And lsof command returned nothing during the run time.

$ lsof /rpas/sbx/na/domains/liasghcom/LIA/data/asoclu.db.lck

$

Questions: