Method, computer program product, and system for pushdown analysis during query plan generation
First Claim
1. A method for query optimization in a heterogeneous database system utilizing pushdown analysis comprising:
- generating a portion of a query plan;
evaluating the portion of the query plan for pushdownability to a remote database system; and
if pushdownable to the remote database system, generating cost parameters for said portion of the plan if executed at a local database system and if executed at the remote database system, the cost parameters adapted for use in determining an optimal query plan.
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Accused Products
Abstract
A method, computer product, and system for pushdown analysis during query plan generation is provided. Rather than do pushdown analysis for portions of a query that are query execution plan independent, the present invention provides pushdown analysis for features of a query that are plan dependent. This is done by evaluating a portion of the query plan for pushdownability to a remote database system; and if pushdownable to the remote database system, generating cost parameters for the portion of the plan if executed at a local database system and if executed at the remote database system. With both sets of cost parameters, the query optimizer has added information on which to select an optimal query plan.
141 Citations
22 Claims
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1. A method for query optimization in a heterogeneous database system utilizing pushdown analysis comprising:
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generating a portion of a query plan;
evaluating the portion of the query plan for pushdownability to a remote database system; and
if pushdownable to the remote database system, generating cost parameters for said portion of the plan if executed at a local database system and if executed at the remote database system, the cost parameters adapted for use in determining an optimal query plan. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A computer program product comprising:
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a computer usable medium; and
computer readable instructions embodied on said computer useable medium for query optimization in a heterogeneous database system utilizing pushdown analysis, the instructions directing a computer to perform the steps of;
generating a portion of a query plan;
evaluating the portion of the query plan for pushdownability to a remote database system; and
if pushdownable to the remote database system, generating cost parameters for said portion of the plan if executed at a local database system and if executed at the remote database system, the cost parameters adapted for use in determining an optimal query plan. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A system for query optimization in a heterogeneous database system utilizing pushdown analysis comprising:
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means for generating a portion of a query plan;
means for evaluating the portion of the query plan for pushdownability to a remote database system; and
if pushdownable to the remote database system, means for generating cost parameters for said portion of the plan if executed at a local database system and if executed at the remote database system, the cost parameters adapted for use in determining an optimal query plan. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A method for query optimization in a heterogeneous database system utilizing pushdown analysis comprising:
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processing, at a local system, incoming queries by building portions of a query plan and combining the portions to create final query plans that are assessed to determine the optimal query plan;
while generating each query plan, evaluating a portion of the plan for pushdownability to a remote database system; and
if pushdownable to the remote database system, generating cost parameters for said portion of the plan if executed at the local database system and if executed at the remote database system, the cost parameters adapted for use in determining the optimal query plan. - View Dependent Claims (20)
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21. In a query optimization phase that generates a plurality of different query execution plans by building portions of a plan and combining the portions to create final plans that are then assessed to determine the optimal query plan, a method for query optimization utilizing pushdown analysis comprising:
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while generating each query plan, evaluating a portion of the plan for pushdownability to a remote system; and
if pushdownable the remote database system, generating cost parameters for said portion of the plan if executed at a local database system and if executed at the remote database system, the cost parameters adapted for use in determining the optimal query plan. - View Dependent Claims (22)
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Specification