US 12,242,458 B2
Transactional query processing in external tables
Margaret M. Susairaj, Sugar Land, TX (US); and Dmitry Mikhailovich Potapov, Los Gatos, CA (US)
Assigned to ORACLE INTERNATIONAL CORPORATION, Redwood Shores, CA (US)
Filed by ORACLE INTERNATIONAL CORPORATION, Redwood Shores, CA (US)
Filed on Jan. 31, 2022, as Appl. No. 17/588,844.
Prior Publication US 2023/0244652 A1, Aug. 3, 2023
Int. Cl. G06F 16/245 (2019.01); G06F 16/23 (2019.01)
CPC G06F 16/2365 (2019.01) [G06F 16/245 (2019.01)] 16 Claims
OG exemplary drawing
 
1. A method, comprising:
a database management system (DBMS) receiving a query that references an external table that is stored in an external table file in a database file system (DBFS) that stores files in a database managed by said DBMS; and
executing said query, wherein executing said query returns query results that are transactionally consistent with a query-consistency time associated with said query, wherein executing said query includes:
a database process executing within a transaction context based on said query consistency time, wherein said transaction context comprises metadata about a transaction associated with the query, and executing within the transaction context comprises the database process having access to at least the transaction context;
determining that said external file is stored within said DBFS;
in response to determining that said external table file is stored within said DBFS, retrieving external data from said external table file, while continuing to execute within said transaction context; and
generating transactionally consistent data that is transactionally consistent with said query consistency time by at least applying consistent-read operations to said external data.