公开(公告)号：US20180341677A1

公开(公告)日：2018-11-29

申请号：US15966465

申请日：2018-04-30

Applicant: Futurewei Technologies, Inc.

Inventor： Wenfei Fan ,  Yang Cao ,  Floris Geerts ,  Ping Lu ,  Yu Chen ,  Demai Ni

IPC: G06F17/30

Abstract: A mechanism for rewriting a bounded query onto a view is disclosed. A query, access constraints, and cached view(s) are obtained. The cached view(s) contain results of the query as applied to a dataset stored in a database. A query rewriting plan is generated by adding a fetch from query operation to the plan when a rewritten query variable can be fetched from a query constant. A fetch from database operation is added to the plan when a rewritten query variable can be fetched as a query variable that obtains bounded data from the database. An access view operation is added to the plan when a rewritten query variable can be fetched from the cached view. The query rewriting plan is executed to fetch retrieved data. The query is executed on the retrieved data to determine updated results to the query without reapplying the query to the dataset.

公开(公告)号：US20170277750A1

公开(公告)日：2017-09-28

申请号：US15082396

申请日：2016-03-28

Applicant: Futurewei Technologies, Inc.

Inventor： Wenfei Fan ,  Yang Cao ,  Floris Geerts ,  Ting Deng ,  Ping Lu

IPC: G06F17/30

CPC classification number: G06F16/24542 ,  G06F16/2453 ,  G06F16/24565

Abstract: A processor executes instructions stored in non-transitory memory to determine whether a query to big data is bounded evaluable, or may be rewritten to access a bounded amount of data or information in a dataset. A query plan may retrieve the information by using indices in access constraints of the query. The cost associated with obtaining the information by using the query plan may be dependent on the query and access constraints and not the size of the dataset. A query plan to obtain the information may be formed for different types or classes of queries, such as conjunctive queries (CQ), unions of conjunctive queries (UCQ) and positive existential FO (first order) conjunctive queries (∃FO+). When a query is not bounded evaluable, a determination is made whether an approximation to the information may be retrieved. An approximation may be obtained by using upper and lower envelopes or specialized queries.

公开(公告)号：US10649994B2

公开(公告)日：2020-05-12

申请号：US15966465

申请日：2018-04-30

Applicant: Futurewei Technologies, Inc.

Inventor： Wenfei Fan ,  Yang Cao ,  Floris Geerts ,  Ping Lu ,  Yu Chen ,  Demai Ni

IPC: G06F16/00 ,  G06F16/2453

Abstract: A mechanism for rewriting a bounded query onto a view is disclosed. A query, access constraints, and cached view(s) are obtained. The cached view(s) contain results of the query as applied to a dataset stored in a database. A query rewriting plan is generated by adding a fetch from query operation to the plan when a rewritten query variable can be fetched from a query constant. A fetch from database operation is added to the plan when a rewritten query variable can be fetched as a query variable that obtains bounded data from the database. An access view operation is added to the plan when a rewritten query variable can be fetched from the cached view. The query rewriting plan is executed to fetch retrieved data. The query is executed on the retrieved data to determine updated results to the query without reapplying the query to the dataset.