Distributed Database System Providing Data and Space Management Methodology
First Claim
1. In a distributed database system having an allocation page for tracking allocation and deallocation of data pages, the allocation page including a deallocation bit for tracking deallocation of a data page, a method for determining when to clear the deallocation bit during recovery, the method comprising:
- during runtime operation of the distributed database system, generating log records recording allocation and deallocation of data pages, setting the deallocation bit during deallocation of a data page by a transaction, and clearing the deallocation bit after the transaction has committed;
during recovery of the distributed database system following a failure, identifying a particular log record corresponding to the deallocation bit set in the allocation page during deallocation of a given data page;
determining whether the deallocation of the given data page recorded in the particular log record committed prior to the failure; and
if the deallocation of the given data page committed prior to the failure, clearing the deallocation bit.
1 Assignment
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Accused Products
Abstract
A distributed database system providing data and space management methodology. In a distributed database system having an allocation page for tracking allocation and deallocation of data pages including a deallocation bit for tracking data page deallocation, a method for determining when to clear the deallocation bit during recovery comprises: during runtime operation, generating log records recording allocation and deallocation of data pages, setting the deallocation bit during deallocation of a data page by a transaction, and clearing the deallocation bit after the transaction has committed; during recovery following a failure, identifying a particular log record corresponding to the deallocation bit set during deallocation of a given data page; determining whether the deallocation of the given data page recorded in the particular log record committed prior to the failure; and if the deallocation of the given data page committed prior to the failure, clearing the deallocation bit.
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Citations
30 Claims
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1. In a distributed database system having an allocation page for tracking allocation and deallocation of data pages, the allocation page including a deallocation bit for tracking deallocation of a data page, a method for determining when to clear the deallocation bit during recovery, the method comprising:
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during runtime operation of the distributed database system, generating log records recording allocation and deallocation of data pages, setting the deallocation bit during deallocation of a data page by a transaction, and clearing the deallocation bit after the transaction has committed; during recovery of the distributed database system following a failure, identifying a particular log record corresponding to the deallocation bit set in the allocation page during deallocation of a given data page; determining whether the deallocation of the given data page recorded in the particular log record committed prior to the failure; and if the deallocation of the given data page committed prior to the failure, clearing the deallocation bit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for tracking allocation and deallocation of database pages in a distributed database system having a plurality of database servers sharing access to data pages, the system comprising:
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an allocation page for tracking allocation and deallocation of data pages in the database system, the allocation page including a deallocation bit for tracking deallocation of a data page, an allocation module for setting the deallocation bit during deallocation of a data page by a transaction, and clearing the deallocation bit after the transaction has committed during runtime operation of the distributed database system; a log module for generating log records recording allocation and deallocation of data pages during runtime operation; and a recovery module for identifying, during recovery of the database server following a failure, a particular log record corresponding to the deallocation bit set in the allocation page during deallocation of a given data page, clearing the deallocation bit if the deallocation of the given data page recorded in the particular log record committed prior to the failure and redoing the deallocation and performing any necessary undo action if the deallocation was not committed prior to failure. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. In a distributed database system including a plurality of servers sharing access to data, an improved method for post-commit processing of transactions, the method comprising:
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maintaining an allocation page timestamp on an allocation page which allocation page timestamp is updated when pages are deallocated; when data pages are deallocated during operation of the distributed database system, setting a deallocation bit on the allocation page; creating log records identifying the deallocated data pages and the allocation page timestamp before and after the deallocation; during database recovery operations following a failure, determining whether to perform post-commit processing for a committed transaction based on examining the log records to determine if the data page deallocation committed and the deallocation bit was set as a result of the data page deallocation reflected in the log records; and performing any post-commit processing determined to be necessary to return the database to a consistent state. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification