Row-store lock changed to fair after 2.5.0 - fairness probably could be made configurable
Feature committed to SVN Revision: 6846. The property hsqldb.fair_locks=false | true, and the SQL statement "SET FILES FAIR LOCKS TRUE | FALSE" are now supported. Performance of the supplied test in improved without fair locking.
core code updates - bug #1751 : added SET FILES FAIR LOCKS TRUE|FALSE and hsqldb.fair_locks property
You can create a bug report and attach the benchmark to it. It's possible to allow a user-defined property for the lock mode.
Regression: General Error in 2.7.5 when using expression in FILTER .. WHERE
Thanks for reporting. Fixed and committed. This issue existed before and relates to the use of MOD function.
core code updates - fix for bug #1750
Good suggestion about "not yet supported". But the feature is in the syntax diagram because it is less work than adding it later.