公开(公告)号：US12038894B2

公开(公告)日：2024-07-16

申请号：US18167134

申请日：2023-02-10

Applicant: Google LLC

Inventor： Viral Shah ,  Xun Cheng ,  Xiaobin Ma ,  Haoyu Huang ,  Anjan Kumar Amirishetty

IPC: G06F16/22 ,  G06F12/02

CPC classification number: G06F16/221 ,  G06F12/023 ,  G06F2212/152

Abstract: Aspects of the disclosure provide for natively executing row-store expression data structures on column-store databases without rewriting. A database management system (DBMS) configured as described herein can maintain a mapping of row-store results to addresses of where corresponding column data is stored. When executing operators, such as logical operators, comparison operators, and/or function operators of a received query expression, the DBMS can operate on the column data, rather than the individual rows. The DBMS can store the results generated by executing the column operators, for example on a stack, and record the row-store addresses to which the stored results correspond. The DBMS responds with a number of rows corresponding to the processed column data.

公开(公告)号：US20230141902A1

公开(公告)日：2023-05-11

申请号：US17521213

申请日：2021-11-08

Applicant: Google LLC

Inventor： Xiaobin Ma ,  Xun Cheng ,  Viral Shah ,  Anjan Kumar Amirishetty

IPC: G06F16/2453 ,  G06F16/2455 ,  G06F16/2452 ,  G06F11/34

CPC classification number: G06F16/24542 ,  G06F16/24552 ,  G06F16/24524 ,  G06F11/3409

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.

公开(公告)号：US20220019539A1

公开(公告)日：2022-01-20

申请号：US16932874

申请日：2020-07-20

Applicant: Google LLC

Inventor： Anjan Kumar Amirishetty ,  Xun Cheng ,  Viral Shah

IPC: G06F12/0871 ,  G06F12/0891 ,  G06F16/2455 ,  G06F16/22 ,  G06F16/27 ,  G06F9/50

Abstract: A method for providing elastic columnar cache includes receiving cache configuration information indicating a maximum size and an incremental size for a cache associated with a user. The cache is configured to store a portion of a table in a row-major format. The method includes caching, in a column-major format, a subset of the plurality of columns of the table in the cache and receiving a plurality of data requests requesting access to the table and associated with a corresponding access pattern requiring access to one or more of the columns. While executing one or more workloads, the method includes, for each column of the table, determining an access frequency indicating a number of times the corresponding column is accessed over a predetermined time period and dynamically adjusting the subset of columns based on the access patterns, the maximum size, and the incremental size.

公开(公告)号：US12130814B2

公开(公告)日：2024-10-29

申请号：US17522504

申请日：2021-11-09

Applicant: Google LLC

Inventor： Xiaobin Ma ,  Xun Cheng ,  Viral Shah ,  Anjan Kumar Amirishetty

IPC: G06F16/2453 ,  G06F16/2455

CPC classification number: G06F16/24544 ,  G06F16/24539 ,  G06F16/24557 ,  G06F16/2456

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：US20230367751A1

公开(公告)日：2023-11-16

申请号：US18167134

申请日：2023-02-10

Applicant: Google LLC

Inventor： Viral Shah ,  Xun Cheng ,  Xiaobin Ma ,  Haoyu Huang ,  Anjan Kumar Amirishetty

IPC: G06F16/22 ,  G06F12/02

CPC classification number: G06F16/221 ,  G06F12/023 ,  G06F2212/152

Abstract: Aspects of the disclosure provide for natively executing row-store expression data structures on column-store databases without rewriting. A database management system (DBMS) configured as described herein can maintain a mapping of row-store results to addresses of where corresponding column data is stored. When executing operators, such as logical operators, comparison operators, and/or function operators of a received query expression, the DBMS can operate on the column data, rather than the individual rows. The DBMS can store the results generated by executing the column operators, for example on a stack, and record the row-store addresses to which the stored results correspond. The DBMS responds with a number of rows corresponding to the processed column data.

公开(公告)号：US20230359562A1

公开(公告)日：2023-11-09

申请号：US17951193

申请日：2022-09-23

Applicant: Google LLC

Inventor： Anjan Kumar Amirishetty ,  Viral Shah

IPC: G06F12/02 ,  G06F12/0815 ,  G06F12/0891

CPC classification number: G06F12/0815 ,  G06F12/0207 ,  G06F12/0891

Abstract: Aspects of the disclosure are directed to maintaining transaction consistency when using a columnar cache. The columnar cache can be initially loaded with all-visible data, and as the data gets modified, respective data is invalidated in the columnar cache. As more data gets invalidated in the columnar cache, respective data can be refreshed in the columnar cache. As part of the refresh, the latest all-visible data can be populated while the queries are still using the old data in the columnar cache. When all the queries transition to use the newly populated data, old data can be removed from the columnar cache. A query can use valid blocks of columnar cache and go to a row store for invalid blocks. When a query starts to use the columnar cache, a request can be submitted to asynchronously prefetch the invalid blocks from the row store.

公开(公告)号：US11334489B2

公开(公告)日：2022-05-17

申请号：US16932874

申请日：2020-07-20

Applicant: Google LLC

Inventor： Anjan Kumar Amirishetty ,  Xun Cheng ,  Viral Shah

IPC: G06F12/08 ,  G06F12/0871 ,  G06F12/0891 ,  G06F9/50 ,  G06F16/22 ,  G06F16/27 ,  G06F16/2455

Abstract: A method for providing elastic columnar cache includes receiving cache configuration information indicating a maximum size and an incremental size for a cache associated with a user. The cache is configured to store a portion of a table in a row-major format. The method includes caching, in a column-major format, a subset of the plurality of columns of the table in the cache and receiving a plurality of data requests requesting access to the table and associated with a corresponding access pattern requiring access to one or more of the columns. While executing one or more workloads, the method includes, for each column of the table, determining an access frequency indicating a number of times the corresponding column is accessed over a predetermined time period and dynamically adjusting the subset of columns based on the access patterns, the maximum size, and the incremental size.