Invention Grant
- Patent Title: Reducing data I/O using in-memory data structures
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Application No.: US15268524Application Date: 2016-09-16
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Publication No.: US10042781B2Publication Date: 2018-08-07
- Inventor: Roger D. MacNicol , Tirthankar Lahiri , Kothanda Umamageswaran , Adrian Tsz Him Ng , Laura Liaoruo Wang , Krishnan Meiyyappan
- 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 ; G06F12/14 ; H04L9/06

Abstract:
Techniques are described herein for generating and using in-memory data structures to represent columns in data block sets. In an embodiment, a database management system (DBMS) receives a query for a target data set managed by the DBMS. The query may specify a predicate for a column of the target data set. The predicate may include a filtering value to be compared with row values of the column of the target data set. Prior to accessing data block sets storing the target data set from persistent storage, the DBMS identifies an in-memory summary that corresponds to a data block set, in an embodiment. The in-memory summary may include in-memory data structures, each representing a column stored in the data block set. The DBMS determines that a particular in-memory data structure exists in the in-memory summary that represents a portion of values of the column indicated in the predicate of the query. Based on the particular in-memory data structure, the DBMS determines whether or not the data block set can possibly contain the filtering value in the column of the target data set. Based on this determination, the DBMS skips or retrieves the data block set from the persistent storage as part of the query evaluation.
Public/Granted literature
- US10198363B2 Reducing data I/O using in-memory data structures Public/Granted day:2019-02-05
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