Techniques for three-step join processing on column partitioned tables
AssigneeTeradata US, Inc.
InventorsMohammed Al-Kateb, Grace Kwan-On Au, Sanjay Sukumaran
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Abstract
Techniques for processing joins on column partitioned tables are provided. A query includes a first-Column Partition (CP) table joined with a second-CP table. The query is decomposed into a three-step process and rewritten and processed.
Claims18
A method implemented and programmed within memory or a non-transitory computer-readable storage medium and processed by one or more processors, the processors configured to execute the method, comprising:
- (1) receiving, via the processor, a query having a join operation on first-column partitioned (CP) table and a second-CP table;
- (2) processing, via the processor, a join condition for the join operation on the first-CP table and the second-CP table to produce a first temporary table that satisfies the join condition;
- (3) performing, via the processor, a rowid join on the first-CP table and the first temporary table to produce a second temporary table;
- and
- (4) joining, via the processor, the second temporary table and the second-CP table, via the rowid join, to produce a results table for the query.
A method implemented and programmed within memory or a non-transitory computer-readable storage medium and processed by a processor, the processor configured to execute the method, comprising:
- detecting, via the processor, a query having a join on a first-column partition (CP) table and a second-CP table;
- and
- processing, via the processor, the query using a three-step process.
A system, comprising:
- memory configured with a join manager that executes on a processor;
- wherein the join manager is configured to decompose a join operation on a first-column partition (CP) table and a second-CP table in a query into a three-step process and permit each step to have resolved costs for selecting a query execution for the query.
Dependencies are inferred from the claim text.