公开(公告)号：US20230135440A1

公开(公告)日：2023-05-04

申请号：US17932140

申请日：2022-09-14

Applicant: Snowflake inc.

Inventor： Thierry Cruanes ,  Sangyong Hwang ,  Nitish Jindal ,  Jiaqi Yan ,  Yongsik Yoon

IPC: G06F16/2453

Abstract: Techniques for join elimination are described herein. Join elimination can identify and eliminate unnecessary joins in a query plan node. For example, join elimination can involve a semantic query optimization technique, which removes reference to a table whose columns are only referenced in join predicates if the joins do not filter/expand rows in the result. Such joins can cause significant performance issues on larger datasets if not optimized.

公开(公告)号：US12045236B2

公开(公告)日：2024-07-23

申请号：US17932140

申请日：2022-09-14

Applicant: Snowflake Inc.

Inventor： Thierry Cruanes ,  Sangyong Hwang ,  Nitish Jindal ,  Jiaqi Yan ,  Yongsik Yoon

IPC: G06F16/2453

CPC classification number: G06F16/24544 ,  G06F16/24537

Abstract: Techniques for join elimination are described herein. Join elimination can identify and eliminate unnecessary joins in a query plan node. For example, join elimination can involve a semantic query optimization technique, which removes reference to a table whose columns are only referenced in join predicates if the joins do not filter/expand rows in the result. Such joins can cause significant performance issues on larger datasets if not optimized.

公开(公告)号：US20240143588A1

公开(公告)日：2024-05-02

申请号：US18400760

申请日：2023-12-29

Applicant: Snowflake Inc.

Inventor： Zixuan Geng ,  Sangyong Hwang ,  Nitish Jindal

IPC: G06F16/2453

CPC classification number: G06F16/24542 ,  G06F16/24537

Abstract: The subject technology receives a first query plan, the first query plan including a set of statements, the set of statements including at least one statement with at least a reference to a particular column in a first table. The subject technology identifies a first predicate from the at least one statement, the first predicate corresponding to a join operation. The subject technology determines, for the particular column, a set of expression properties. The subject technology, based on the set of expression properties, determines a first derived predicate, the first derived predicate corresponding to a first filter operation. The subject technology generates a new operation based on the first derived predicate. The subject technology generates a new query plan based at least in part on the join operation of first predicate, the first derived predicate, and the new operation of the first derived predicate.

公开(公告)号：US11893016B1

公开(公告)日：2024-02-06

申请号：US18049904

申请日：2022-10-26

Applicant: Snowflake Inc.

Inventor： Zixuan Geng ,  Sangyong Hwang ,  Nitish Jindal

IPC: G06F16/24 ,  G06F16/2453

CPC classification number: G06F16/24542 ,  G06F16/24537

Abstract: The subject technology provides embodiments for enabling derivation of predicates not only from other predicates but also from metadata such as expression properties. In examples, predicates are derived, avoiding unwanted impact on cardinality estimation. In other examples, predicates are derived, avoiding artificial runtime errors and providing a way to avoid security issues with secure views.

公开(公告)号：US20240338367A1

公开(公告)日：2024-10-10

申请号：US18746644

申请日：2024-06-18

Applicant: Snowflake Inc.

Inventor： Thierry Cruanes ,  Sangyong Hwang ,  Nitish Jindal ,  Jiaqi Yan ,  Yongsik Yoon

IPC: G06F16/2453

CPC classification number: G06F16/24544 ,  G06F16/24537

Abstract: Techniques for join elimination are described herein. Join elimination can identify and eliminate unnecessary joins in a query plan node. For example, join elimination can involve a semantic query optimization technique, which removes reference to a table whose columns are only referenced in join predicates if the joins do not filter/expand rows in the result. Such joins can cause significant performance issues on larger datasets if not optimized.