COMBINING CAPTURE AND APPLY IN A DISTRIBUTED INFORMATION SHARING SYSTEM
First Claim
1. A method for consuming logical change records at a sink node by an apply process, comprising:
- setting up a memory structure specifically for a capture process, wherein the capture process is remotely located at a source entity and is associated with the apply process at the sink entity;
receiving a message in a continuous stream of messages from the capture process, wherein the stream of messages comprises interesting logical change records continuously captured at the source entity by the capture process;
storing, without taking any latches on the memory structure, the message in the continuous stream of messages in the memory structure;
consuming, without taking any latches on the memory structure, the message among one or more messages that are stored in the memory structure, wherein the one or more messages are part of the continuous stream of messages; and
removing the message from the memory structure.
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Accused Products
Abstract
In accordance with an embodiment of the present invention, an information sharing mechanism comprising a memory structure may be provided in a database system. In an embodiment, mined information transferred by a capture process to an associated apply process can be written into the memory structure without taking any latch. Similarly, the mined information can be read by the apply process from the memory structure without taking any latch. The capture and apply processes may work cooperatively to establish a safe point in log mining under various circumstances such as in an initial startup state, in a steady state, in a process restart scenario in the middle of information sharing. In some embodiments, the information sharing mechanism supports both checkpoint-free and checkpoint modes of log mining by the capture process. In addition, both the capture process and the apply process may employ an eager apply approach to increase processing capacity.
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Citations
28 Claims
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1. A method for consuming logical change records at a sink node by an apply process, comprising:
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setting up a memory structure specifically for a capture process, wherein the capture process is remotely located at a source entity and is associated with the apply process at the sink entity; receiving a message in a continuous stream of messages from the capture process, wherein the stream of messages comprises interesting logical change records continuously captured at the source entity by the capture process; storing, without taking any latches on the memory structure, the message in the continuous stream of messages in the memory structure; consuming, without taking any latches on the memory structure, the message among one or more messages that are stored in the memory structure, wherein the one or more messages are part of the continuous stream of messages; and removing the message from the memory structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification