Cost-based semi-join rewrite
    2.
    发明授权

    公开(公告)号:US12105708B2

    公开(公告)日:2024-10-01

    申请号:US17566442

    申请日:2021-12-30

    申请人: Teradata US, Inc

    IPC分类号: G06F16/23 G06F16/2453

    CPC分类号: G06F16/24544 G06F16/24545

    摘要: A method, apparatus, and computer program product for executing a relational database management system (RDBMS) in a computer system, wherein the RDBMS manages a relational database comprised of one or more tables storing data. The RDBMS executes a query with a semi-join operation comprising an inclusion join and/or an exclusion join performed against at least an outer table and an inner table, wherein the inclusion join returns a row from the outer table when there is a match with a row in the inner table, and the exclusion join returns a row from the outer table when there is no match with a row in the inner table. The RDBMS performs a rewrite of the query to avoid spooling and/or sorting of the inner table, when the inner table is larger than the outer table and a cost after the rewrite is lower than before the rewrite.

    GARBAGE COLLECTION BASED ON METADATA INDICATING UNMODIFIED OBJECTS

    公开(公告)号:US20240160617A1

    公开(公告)日:2024-05-16

    申请号:US18054642

    申请日:2022-11-11

    申请人: TERADATA US, INC.

    IPC分类号: G06F16/23 G06F12/02

    摘要: In some examples, a database system accesses a plurality of objects in a remote object store. In response to a query to change data in a first object of the plurality of objects, the database system specifies the first object prior to the change as a first version of the first object, and creates a second version of the first object after the change. The database system maintains metadata identifying unmodified objects of the plurality of objects, and during a garbage collection process when deciding whether to remove a given object of the plurality of objects, accesses the metadata to determine whether the given object has been modified, and prevents removal of the given object in response to determining that the given object is unmodified.

    ESTIMATOR OF RESOURCE CONSUMPTION BY QUERY EXECUTION PLAN STEPS

    公开(公告)号:US20240143589A1

    公开(公告)日:2024-05-02

    申请号:US17974861

    申请日:2022-10-27

    申请人: Teradata US, Inc.

    IPC分类号: G06F16/2453 G06N20/20

    CPC分类号: G06F16/24545 G06N20/20

    摘要: A method, apparatus and computer program product for estimating resource consumption for steps in a query execution plan for a query performed by a relational database management system (RDBMS) in a computer system. Past execution data for the steps are used to train a machine learning (ML) model and its model parameters to predict execution times for the steps. A prediction module comprised of the ML model configured by the model parameters predicts an execution time for a current step of the query execution plan for the query, based on current step information and current system load. A boosting module boosts the current step either up or down for processing by the RDBMS to meet a service level goal (SLG) for the query, based on the predicted execution time for the current step, as well as an elapsed query time, a query SLG time, and/or a query CPU time.

    SEMI-MATERIALIZED VIEWS
    5.
    发明公开

    公开(公告)号:US20230350864A1

    公开(公告)日:2023-11-02

    申请号:US17661066

    申请日:2022-04-28

    申请人: TERADATA US, INC.

    IPC分类号: G06F16/2453

    CPC分类号: G06F16/24539 G06F16/24537

    摘要: A database system includes a storage medium to store a semi-materialized view (MV) defined on an MV condition, the semi-MV including metadata containing references to objects containing data of one or more tables that satisfy the MV condition, the objects stored in a remote data store that is coupled to the database system over a network. The database system includes at least one processor to receive a query including a query condition, determine that the semi-MV can be used to satisfy the query based on the MV condition and the query condition, and use the metadata in the semi-MV to retrieve data of the objects in the remote data store for the query.

    Non-unique secondary indexing of semi-structured data in databases

    公开(公告)号:US11347794B2

    公开(公告)日:2022-05-31

    申请号:US15386049

    申请日:2016-12-21

    申请人: Teradata US, Inc.

    IPC分类号: G06F16/00 G06F16/81 G06F16/22

    摘要: Various embodiments herein each include at least one of systems, methods, and software for generating, storing, and using non-unique secondary indexes of semi-structured data in database tables. One method embodiment includes creating and storing a non-unique secondary index (NUSI) for a database table based on column data stored in rows of the database table. The NUSI in some such embodiments identifying an offset to specific data included in the column data of at least some rows of the database table where the specific data is located. Other embodiments include building a NUSI index that includes values embedded therein.