Fair scheduling for mixed-query loads
First Claim
Patent Images
1. A computing system, comprising:
- one or more processors;
storage media;
one or more programs stored in the storage media and configured for execution by the one or more processors, the one or more programs comprising instructions configured for;
obtaining a query for execution by a database management system and a cost estimate for the database management system to execute the query;
enqueuing an item for the query onto a queue, the queue having a head, a tail, and a maximum number of allowed items;
based, at least in part, on the cost estimate, dividing the query into a plurality of sub-queries;
based, at least in part, on an item for the query reaching the head of the queue, causing a first sub-query of the plurality of sub-queries to be executed by the database management system; and
based, at least in part, on determining there are more sub-queries of the plurality of sub-queries to be executed by the database management system;
re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is less than the maximum number of allowed items, orwaiting until a current number of items in the queue is less than the maximum number of allowed items before re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is not less than the maximum number of allowed items.
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Abstract
A fair scheduling system with methodology for scheduling queries for execution by a database management system in a fair manner. The system obtains query jobs for execution by the database management system and cost estimates to execute the query jobs. Based on the cost estimates, the system causes the database management system to execute the query jobs as separate sub-query tasks in a round-robin fashion. By doing so, the execution latency of low cost query jobs that return few results is reduced when the query jobs are concurrently executed with high cost query jobs that return many results.
901 Citations
21 Claims
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1. A computing system, comprising:
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one or more processors; storage media; one or more programs stored in the storage media and configured for execution by the one or more processors, the one or more programs comprising instructions configured for; obtaining a query for execution by a database management system and a cost estimate for the database management system to execute the query; enqueuing an item for the query onto a queue, the queue having a head, a tail, and a maximum number of allowed items; based, at least in part, on the cost estimate, dividing the query into a plurality of sub-queries; based, at least in part, on an item for the query reaching the head of the queue, causing a first sub-query of the plurality of sub-queries to be executed by the database management system; and based, at least in part, on determining there are more sub-queries of the plurality of sub-queries to be executed by the database management system; re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is less than the maximum number of allowed items, or waiting until a current number of items in the queue is less than the maximum number of allowed items before re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is not less than the maximum number of allowed items. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method performed by a computing system comprising one or more processors, storage media, and one or more programs stored in the storage media and executed by the one or more processors to perform the method, the method comprising:
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obtaining a query for execution by a database management system and a cost estimate for the database management system to execute the query; enqueuing an item for the query onto a queue, the queue having a head, a tail, and a maximum number of allowed items; based, at least in part, on the cost estimate, dividing the query into a plurality of sub -queries; based, at least in part, on an item for the query reaching the head of the queue, causing a first sub-query of the plurality of sub-queries to be executed by the database management system; and based, at least in part, on determining there are more sub-queries of the plurality of sub -queries to be executed by the database management system; re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is less than the maximum number of allowed items, or waiting until a current number of items in the queue is less than the maximum number of allowed items before re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is not less than the maximum number of allowed items. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. One or more non-transitory computer-readable media storing one or more one or more programs for execution by a computing system comprising one or more processors and storage media, the one or more programs comprising instructions configured for:
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obtaining a query for execution by a database management system and a cost estimate for the database management system to execute the query; enqueuing an item for the query onto a queue, the queue having a head, a tail, and a maximum number of allowed items; based, at least in part, on the cost estimate, dividing the query into a plurality of sub -queries; based, at least in part, on an item for the query reaching the head of the queue, causing a first sub-query of the plurality of sub-queries to be executed by the database management system; and based, at least in part, on determining there are more sub-queries of the plurality of sub -queries to be executed by the database management system; re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is less than the maximum number of allowed items, or waiting until a current number of items in the queue is less than the maximum number of allowed items before re-enqueuing an item for the query onto the tail of the queue if a current number of items in the queue is not less than the maximum number of allowed items. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification