Method of using a cache to determine the visibility to a remote database client of a plurality of database transactions

An article of manufacture comprising:

• (a) a computer usable medium including computer usable program code embodied therein for managing a partially replicated database by:
• (i) determining whether a visibility of a user of a partially replicated database to data being propagated is stored in a cache memory, and if so, accessing the visibility from the cache memory, and if not, determining the visibility, and storing the visibility in the cache memory;
• and
• (ii) propagating said data to a partially replicated database only if the user has visibility to the data.

A method of selectively transmitting a transaction from a central database to at least one node having a partially replicated database out of a plurality of nodes having partially replicated databases, comprising the steps of:

• (a) encoding the transaction in a docking object representing the transaction and including at least two tables from the central database, one of the tables containing visibility rules controlling whether a particular instance of the docking object is visible to a particular node, said visibility rule including either:
• (1) a set of statements that are evaluated to determine if any data meeting criteria specified in the statements exists in the docking object, or
• (2) a pointer to another docking object containing a set of statements to be evaluated as in (a)(1);
• (b) selecting a node;
• (c) determining whether the visibility of the selected node to the particular instance of the docking object is stored in a cache memory, and if so, accessing the visibility from the cache memory, and if not,
• (i) executing the visibility rule against the selected node to determine whether the particular instance of the docking object is visible to the selected node, and
• (ii) storing in cache memory the visibility of the node;
• and
• (d) selectively transmitting the transaction to the selected node depending on whether the particular instance of the docking object is visible to the selected node.

A system for selectively transmitting a transaction from a central database residing in a server to at least one node having a partially replicated database out of a plurality of nodes having partially replicated databases, the system being configured to carry out the method comprising the steps of:

• (a) encoding the transaction in a docking object representing the transaction and including at least two tables from the central database, one of the tables containing visibility rules controlling whether a particular instance of the docking object is visible to a particular node, said visibility rule including either:
• (1) a set of statements that are evaluated to determine if any data meeting criteria specified in the statements exists in the docking object, or
• (2) a pointer to another docking object containing a set of statements to be evaluated as in (a)(1);
• (b) selecting a node;
• (c) determining whether the visibility of the selected node to the particular instance of the docking object is stored in a cache memory, and if so, accessing the visibility from the cache memory, and if not,
• (i) executing the visibility rule against the selected node to determine whether the particular instance of the docking object is visible to the selected node, and
• (ii) storing in cache memory the visibility of the node;
• and
• (d) selectively transmitting the transaction to the selected node depending on whether the particular instance of the docking object is visible to the selected node.

A system for managing a database said database including

• a central database, and
• separate partially replicated databases, each having separate users, where the system is configured to carry out the method comprising the steps of
• (a) determining whether a visibility of a user of a partially replicated database to data being propagated from the central database is stored in a cache memory, and if so, accessing the visibility from the cache memory, and if not, determining the visibility and storing the visibility in the cache memory;
• (b) propagating said data to the partially replicated database only if the user of the partially replicated database has visibility to the data.