Invention Grant
- Patent Title: Techniques for evaluating query predicates during in-memory table scans
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Application No.: US14806614Application Date: 2015-07-22
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Publication No.: US10025823B2Publication Date: 2018-07-17
- Inventor: Dinesh Das , Jiaqi Yan , Mohamed Zait , Nirav Vyas
- Applicant: Oracle International Corporation
- Applicant Address: US CA Redwood Shores
- Assignee: Oracle International Corporation
- Current Assignee: Oracle International Corporation
- Current Assignee Address: US CA Redwood Shores
- Agency: Hickman Palermo Becker Bingham LLP
- Main IPC: G06F17/30
- IPC: G06F17/30 ; G06F12/02

Abstract:
Techniques are described herein for filtering data from a table during an in-memory scan. Predicates are pushed to in-memory scan to avoid scanning unnecessary columnar units and reduce the overhead of decompressing, row stitching and distributing data during evaluation. Techniques are described herein for generating implied predicates that have conditions on single columns from complex predicates that have multiple conditions on the same column, which can be evaluated during an in-memory scan. Techniques are also described herein to reduce the overhead of a table scan for processing a join query. When redistributing a first table for performing a hash-join, the nodes performing an in-memory scan of the first table may create a filter that tracks unique values from the join key. Data from the second table is only processed and transferred to other nodes in the cluster if the values from the join key pass through the filter.
Public/Granted literature
- US20160350347A1 TECHNIQUES FOR EVALUATING QUERY PREDICATES DURING IN-MEMORY TABLE SCANS Public/Granted day:2016-12-01
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