root.psa_db.sql.lock undocumented feature?

[StéphanS]

Can anybody tell me what the file $PRODUCT_ROOT_D/etc/root.psa_db.sql.lock is for?
It is referred to @ http://serverkb.co.uk/wiki/Plesk_Errors

I'd like to know more about hardening my Plesk installs.

 

[IgorG]

This wiki looks useful but there are some inaccuracies. For instance, Plesk handles parameters $PRODUCT_ROOT_D/var/root.crontab.lock and $PRODUCT_ROOT_D/var/root.event_handler.lock
Parameter $PRODUCT_ROOT_D/etc/root.psa_db.sql.lock is not handled by any Plesk versions.