question: public void unlockReadLocks ( ) { if ( database . isMultiVersion ( ) ) { return ; } for ( int i = 0 ; i < locks . size ( ) ; i ++ ) { Table t = locks . get ( i ) ; if ( ! t . isLockedExclusively ( ) ) { synchronized ( database ) { t . unlock ( this ) ; locks . remove ( i ) ; } i -- ; } } }
target:  Unlock all read locks. This is done if the transaction isolation mode is READ_COMMITTED.