Propagating a query in a federated database

摘要

A method for propagating a query in a system made up of a number connectable database management system nodes, where each node is associated at least one database, includes: selecting a first node from the number of nodes; generating at least one connection operable to propagate a query from the first node to a first subset of the number of nodes; generating at least one connection operable to propagate a query from a second node in the first subset to a second subset of the plurality of nodes; where at least one node in the second subset is different from nodes in the first subset.

主权项

1. A method for adding a new node in a system comprising a plurality of connectable database management system nodes, each of said database management system nodes comprising at least one database, the method comprising:
with a first node of said plurality of nodes, receiving a message requesting to add said new node to said system; with said first node, propagating a query relating to said message to a number of other nodes, wherein said query is associated with a query identifier; with said first node, generating a maximum delay time to wait before sending a second message, said maximum delay time being inversely proportional to a number of existing connections between said first node and other nodes within said plurality of nodes; with said first node, generating a second message in response to said new node after waiting a delay time, said delay time being a randomly selected time between 0 and said maximum delay time; and with said first node, forming a connection with said new node when said second message from said first node to said new node is a first message returned to said new node by any of said plurality of nodes.