Workload-based sampling
AssigneeSap SE
InventorsAxel Hertzschuch, Norman May, Lars Fricke, Florian Wolf, Guido Moerkotte, Wolfgang Lehner
Life of this patent
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Abstract
A system includes determination of a plurality of queries of a workload, determination of a data source comprising a plurality of data rows, and determination of a sample data source based on a cardinality of each of the plurality of queries with respect to the data source and an estimated cardinality of each of the plurality of queries with respect to the data source, wherein the estimated cardinality of a query with respect to the data source is determined based on the sample data source.
Claims15
A system comprising:
- a memory storing processor-executable program code;
- and
- a processing unit to execute the processor-executable program code in order to cause the system to:
- determine a plurality of queries of a workload;
- determine a data source comprising a plurality of data rows;
- and
- determine a sample data source based on a cardinality of each of the plurality of queries with respect to the data source and an estimated cardinality of each of the plurality of queries with respect to the data source by:
- for each of the plurality of queries, determining a decrease in a cardinality estimation error associated with addition of each of candidate rows of the data source to the sample data source;
- and
- selecting a candidate row to add to the sample data source based on the determined decreases,
- wherein the estimated cardinality of a query with respect to the data source is determined based on the sample data source.
A computer-implemented method, comprising:
- determining a plurality of queries;
- determining a data source comprising a plurality of data rows;
- and
- determining a sample data source comprising a plurality of the plurality of data rows based on a cardinality of each of the plurality of queries with respect to the data source and an estimated cardinality of each of the plurality of queries with respect to the data source by:
- for each of the plurality of queries, determining a decrease in a cardinality estimation error associated with addition of each of candidate rows of the data source to the sample data source;
- and
- selecting a candidate row to add to the sample data source based on the determined decreases,
- wherein the estimated cardinality of a query with respect to the data source is determined based on data rows of the sample data source.
A non-transitory computer-readable medium storing program code executable by a processing unit to:
- determine a plurality of queries of a workload;
- and
- determine a sample data source based on a cardinality of each of the plurality of queries with respect to a data source comprising a plurality of data rows and an estimated cardinality of each of the plurality of queries with respect to the data source by:
- for each of the plurality of queries, determination of a decrease in a cardinality estimation error associated with addition of each of candidate rows of the data source to the sample data source;
- and
- selection of a candidate row to add to the sample data source based on the determined decreases,
- wherein the estimated cardinality of a query with respect to the data source is determined based on the sample data source.
Dependencies are inferred from the claim text.