Data verification following database write
AssigneeEMC Corporation
InventorsArieh Don, Philip E. Tamer, Alexandr Veprinsky, Xiali He, Terry Seto Lee
Life of this patent
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Abstract
A method for processing a request from a host to write a database record to a target location on a logical device associated with a data-storage system in data communication with the host includes maintaining, at the data storage system, information identifying extents of the logical device that are designated for storage of database records, and, on the basis of the information, determining whether the target location is one on which a database record is permitted to be stored.
Claims15
In a data storage system that stores both database records and ancillary data, a method for processing a request from a host to write a database record to a target location on a logical device associated with a data-storage system in data communication with the host, the logical device having a first set of extents designated for storage of database records and a second set of extents designated for storage of ancillary data, the method comprising:
- maintaining, at the data storage system, an extent-table having information for distinguishing between the first set of extents and the second set of extents, each of the extents being associated with a corresponding set of processing instructions;
- based on the information, determining that the target location is on an extent that is designated for storage of a database record, and that the target location is not on an extent that is designated for storage of ancillary data, the ancillary data being different from the database record and not subject to data verification, whereby the database record is not written to an extent that is designated for storage of ancillary data;
- and
- writing the database record only to an extent that is designated for storage of a database record.
A method of processing an Input-or-Output request to access a storage device having a plurality of extents defined thereon, each of the extents having a corresponding set of processing instructions associated therewith, the method comprising:
- receiving an Input-or-Output request having an associated target location on the storage device;
- identifying, based on an extent-table, an extent set associated with the target location, the extent set having at least a first extent and a second extent, the extent-table having information for distinguishing between the first extent and the second extent, each of the first and second extents having its own associated processing instructions in which data stored in the first extent are associated with a database record and are subject to data verification, and data stored in the second extent are associated with ancillary data and are not subject to data verification, the ancillary data being different from the database record;
- maintaining the extent-table;
- determining that execution of the processing instructions for a first extent does not preclude execution of processing instructions for the second extent;
- executing the Input-or-Output request;
- executing the processing instructions associated with the first extent;
- and
- executing the processing instructions associated with the second extent;
- wherein the database record is only written to an extent that is designated for storage of a database record.
A computer-readable medium having encoded thereon software for causing a data storage system that stores both database records and data other than database records to process a request from a host to write a database record to a target location on a logical device associated with a data-storage system in data communication with the host, the logical device having a first set of extents designated for storage of database records and a second set of extents designated for storage of ancillary data, the software comprising instructions that, when executed, cause a computer to:
- maintain, at the data storage system, an extent-table having information for distinguishing between the first set of extents and the second set of extents, each of the extents being associated with a corresponding set of processing instructions;
- and
- based on the information in the extent-table, determine that the target location is on an extent that is designated for storage of a database record, and that the target location is not on an extent that is designated for storage of ancillary data, the ancillary data being different from the database record and not subject to data verification,
- whereby the database record is written only to an extent that is designated for storage of a database record, and
- whereby the database record is not written to an extent that is designated for storage of ancillary data.
A computer-readable medium having encoded thereon software for processing an Input-or-Output request to access a storage device having a plurality of extents defined thereon, each of the extents having a corresponding set of processing instructions associated therewith, the software including instructions that, when executed, cause a computer to:
- receive an Input-or-Output request having an associated target location on the storage device;
- identify, based on an extent-table, an extent set associated with the target location, the extent set having at least a first extent and a second extent, the extent-table having information for distinguishing between the first extent and the second extent, each of the first and second extents having its own associated processing instructions in which data stored in the first extent associated with a database record and are subject to data verification, and data stored in the second extent are associated with ancillary data and are not subject to data verification, the ancillary data being different from the database record;
- maintain the extent-table;
- determine that execution of the processing instructions for a first extent does not preclude execution of processing instructions for the second extent;
- execute the Input-or-Output request;
- execute the processing instructions associated with the first extent;
- and
- execute the processing instructions associated with the second extent;
- wherein the database record is only written to an extent that is designated for storage of a database record.
Dependencies are inferred from the claim text.