LOAD ESTIMATING SYSTEM AND COMPUTER LOAD ESTIMATING METHOD
First Claim
1. A load estimating system which estimates a load of a database, comprising:
- a storage unit configured to include structure information defining a structure of a table in said database, first distribution information indicating probability distribution of condition variables of a query for said table, and second distribution information indicating probability distribution of values in said table;
a record number calculating module configured to calculate the average number of selected records which meet conditions defined by condition variables, based on said structure information, said first distribution information and said second distribution information; and
an access number calculating module configured to calculate the number of block accesses for said query based on the average number of selected records.
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Accused Products
Abstract
A load estimating system which estimates a load of a database, includes a storage unit, a record number calculating module, and an access number calculating module. The storage unit includes structure information defining a structure of a table in said database, first distribution information indicating probability distribution of condition variables of a query for said table, and second distribution information indicating probability distribution of values in said table. The record number calculating module calculates the average number of selected records which meet conditions defined by-condition variables, based on said structure information, said first distribution information and said second distribution information. The access number calculating module calculates the number of block accesses for said query based on the average number of selected records.
32 Citations
19 Claims
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1. A load estimating system which estimates a load of a database, comprising:
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a storage unit configured to include structure information defining a structure of a table in said database, first distribution information indicating probability distribution of condition variables of a query for said table, and second distribution information indicating probability distribution of values in said table; a record number calculating module configured to calculate the average number of selected records which meet conditions defined by condition variables, based on said structure information, said first distribution information and said second distribution information; and an access number calculating module configured to calculate the number of block accesses for said query based on the average number of selected records. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of estimating a computer load, which estimates a load of a database, comprising:
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reading structure information defining a structure of a table in said database from a storage unit; reading first distribution information indicating probability distribution of condition variables of a query for said table from said storage unit; reading second distribution information indicating probability distribution of values in said table from said storage unit; calculating the average number of selected records which meet conditions defined by condition variables, based on said structure information, said first distribution information and said second distribution information; and calculating the number of block accesses for said query based on the average number of selected records. - View Dependent Claims (15, 16)
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17. A computer program product for a method of estimating a computer load, which estimates a load of a database, embodied on a computer-readable medium and comprising code that, when executed, causes a computer to perform the following:
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reading structure information defining a structure of a table in said database from a storage unit; reading first distribution information indicating probability distribution of condition variables of a query for said table from said storage unit; reading second distribution information indicating probability distribution of values in said table from said storage unit; calculating the average number of selected records which meet conditions defined by condition variables, based on said structure information, based on said structure information, said first distribution information and said second distribution information; and calculating the number of block accesses for said query based on the average number of selected records. - View Dependent Claims (18, 19)
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Specification