Patent ID: 7269588

Claim:
A database management system, comprising: a processor providing a neighborhood locking scheme for a neighborhood of free space adjacent to and associated with a data item and extending to an adjacent data item, the neighborhood locking scheme concurrently creating both a first locking mode for the data item, while at the same time creating a second locking mode for the neighborhood associated with the data item; where the first locking mode when first held on the data item determines an associated set of predetermined access restrictions for the data item and determines an associated different set of predetermined access restrictions for the neighborhood associated with the data item; where the second locking mode when first held on the neighborhood determines the associated set of predetermined access restrictions for the neighborhood and determines the associated different set of predetermined access restrictions for the data item; wherein the neighborhood locking scheme includes a neighborhood lock mode that grants a first transaction an exclusive lock on a first tuple and a weak lock on the neighborhood associated with the first tuple; and wherein the neighborhood lock mode grants a second concurrent transaction an exclusive lock on a second tuple located in the neighborhood of the first tuple.