公开(公告)号：WO2023086322A1

公开(公告)日：2023-05-19

申请号：PCT/US2022/049235

申请日：2022-11-08

Applicant: GOOGLE LLC

Inventor： MA, Xiaobin ,  CHENG, Xun ,  SHAH, Viral ,  AMIRISHETTY, Anjan, Kumar

IPC: G06F16/2453 ,  G06F16/2455

Abstract: Aspects of the disclosure are directed to late materialization of attributes in response to queries to a database implementing a database cache. Queried data is materialized in temporary memory before the data is projected as part of generating a result to the query. Instead of materializing all of the attributes referenced in a query before executing the query, a database management system materializes attributes as "late" as possible—when the operation needing the attributes is executed. The operation needing the attributes can be performed sooner, as opposed to materializing all referenced attributes are materialized before executing the query.

公开(公告)号：WO2023081153A1

公开(公告)日：2023-05-11

申请号：PCT/US2022/048578

申请日：2022-11-01

Applicant: GOOGLE LLC

Inventor： MA, Xiaobin ,  CHENG, Xun ,  SHAH, Viral ,  AMIRISHETTY, Anjan, Kumar

IPC: G06F16/2452

Abstract: Aspects of the disclosure are directed to generating a hybrid query execution plan for executing queries on database systems implementing a columnar cache. A hybrid query execution plan combines a query execution plan for querying and retrieving data from a columnar cache and a base table. A columnar cache stores cached data in column-major format, which is logically represented by the database management system in row-major format. A database management system as described herein can scan valid blocks of column data according to a column scan operation. The system can identify invalidated blocks and execute a different sub-execution plan of the hybrid query execution plan to scan corresponding rows in tables corresponding to the location of data for the invalidated blocks.