公开(公告)号：US20200004517A1

公开(公告)日：2020-01-02

申请号：US16565254

申请日：2019-09-09

Applicant: SAP SE

Inventor： Thomas Legler

IPC: G06F8/41 ,  G06F16/22 ,  G06F12/0862 ,  G06F16/2455 ,  G06F12/0844

Abstract: A system for cache efficient reading of column values in a database is provided. In some aspects, the system performs operations including pre-fetching, asynchronously and in response to a request for data in a column store database system, a plurality of first values associated with the requested data. The request may identify a row of the column store database system associated with the requested data. The plurality of first values may be located in the row. The operations may further include storing the plurality of first values in a cache memory. The operations may further include pre-fetching, asynchronously and based on the plurality of first values, a plurality of second values. The operations may further include storing the plurality of second values in the cache memory. The operations may further include reading, in response to the storing the plurality of second values, the requested data from the cache memory.

公开(公告)号：US20190311052A1

公开(公告)日：2019-10-10

申请号：US15945715

申请日：2018-04-04

Applicant: SAP SE

Inventor： Klaus Otto Mueller ,  Thomas Legler

IPC: G06F17/30 ,  G06F9/445

Abstract: A system for unloading tables of a database is provided. In some aspects, the system performs operations including determining that a number of accesses to a table occurring within a time period has satisfied an access threshold. The operations may further include identifying, in response to the determining, a first timestamp indicating a most recent access to the table. The operations may further include determining whether a difference between a current timestamp and the first timestamp satisfies a first time threshold. The operations may further include comparing, in response to the difference satisfying the first time threshold, a ratio of the difference and a size of the table to a ratio threshold. The operations may further include unloading, in response to satisfying the ratio threshold, the table. The operations may further include adjusting, based on the feedback, the first time threshold and/or the ratio threshold.

公开(公告)号：US10204133B2

公开(公告)日：2019-02-12

申请号：US15401678

申请日：2017-01-09

Applicant: SAP SE

Inventor： Thomas Legler

IPC: G06F17/30

Abstract: Performing optimized update operations in in-memory database systems. Update values corresponding to a source table of values stored on an in-memory database are identified by an in-memory database computer system based on information from a computer system implementing a software application. The update values are distributed across a plurality of rows, each row including a plurality of column attributes. At least some column attributes of the plurality of column attributes include values updated relative to corresponding column attributes in the source table of values. A row of the update values is identified. The row includes a plurality of column attributes, each column attribute having a respective value. Each value of each column attribute of the row of the update values is the same as a corresponding value of a corresponding attribute of a corresponding row of the source table is determined. Upon such a determination, a corresponding row of the source table stored on the in-memory database is written into the in-memory database by the in-memory database computer system.

公开(公告)号：US20180137173A1

公开(公告)日：2018-05-17

申请号：US15351547

申请日：2016-11-15

Applicant: SAP SE

Inventor： Thomas Legler

IPC: G06F17/30

CPC classification number: G06F16/221 ,  G06F16/24556

Abstract: Disclosed herein are system, method, and computer program product embodiments for generating a data structure and responding to an aggregation query. An embodiment operates by a computer implemented method that includes receiving, by at least one processor, a request to enter data in a block in a data structure. The method further includes reading, by the at least one processor, a first aggregated value stored in the data structure. The first aggregated value represents a sum over at least values associated with data that is stored in the block in the data structure. The method further includes calculating, by the at least one processor, a second aggregated value by adding the first aggregated value and a value associated with the data to be entered in the data structure. The method further includes storing, by the at least one processor, at least part of the data to be entered and the second aggregated value in the block in the data structure. After the storing, the second aggregated value represents the sum over the at least values associated with the data that is stored in the block in the data structure.

公开(公告)号：US20170116258A1

公开(公告)日：2017-04-27

申请号：US15401678

申请日：2017-01-09

Applicant: SAP SE

Inventor： Thomas Legler

IPC: G06F17/30

CPC classification number: G06F17/30377 ,  G06F17/30339 ,  G06F17/30345

Abstract: Performing optimized update operations in in-memory database systems. Update values corresponding to a source table of values stored on an in-memory database are identified by an in-memory database computer system based on information from a computer system implementing a software application. The update values are distributed across a plurality of rows, each row including a plurality of column attributes. At least some column attributes of the plurality of column attributes include values updated relative to corresponding column attributes in the source table of values. A row of the update values is identified. The row includes a plurality of column attributes, each column attribute having a respective value. Each value of each column attribute of the row of the update values is the same as a corresponding value of a corresponding attribute of a corresponding row of the source table is determined. Upon such a determination, a corresponding row of the source table stored on the in-memory database is written into the in-memory database by the in-memory database computer system.

公开(公告)号：US20160378750A1

公开(公告)日：2016-12-29

申请号：US14748036

申请日：2015-06-23

Applicant: SAP SE

Inventor： Thomas Legler ,  Peter Steinemann

IPC: G06F17/30

CPC classification number: G06F17/3033

Abstract: The subject matter disclosed herein provides methods for inserting and retrieving value identifiers from a dictionary encoded database using hash maps. A first value identifier and a first value can be accessed from a dictionary storing one or more value identifiers and one or more values. Each value identifier can correspond to a different value. The hash map and the first value can be used to determine a first index in a bucket list for inserting the first value identifier. The bucket list can have one or more indices. Each index can store at least one value identifier. The hash map can include a vector of one or more pointers. Each pointer can refer to at least one of the indices. Based on the determining, the first value identifier can be inserted at the first index without inserting the first value. Related apparatus, systems, techniques, and articles are also described.

Abstract translation: 本文公开的主题提供了使用散列图从字典编码的数据库中插入和检索值标识符的方法。 可以从存储一个或多个值标识符和一个或多个值的字典中访问第一值标识符和第一值。 每个值标识符可以对应于不同的值。 散列图和第一值可用于确定用于插入第一值标识符的桶列表中的第一索引。 桶列表可以有一个或多个索引。 每个索引可以存储至少一个值标识符。 哈希映射可以包括一个或多个指针的向量。 每个指针可以指代至少一个索引。 基于该确定，可以在第一个索引处插入第一个值标识符而不插入第一个值。 还描述了相关装置，系统，技术和制品。

公开(公告)号：US11947994B2

公开(公告)日：2024-04-02

申请号：US16367910

申请日：2019-03-28

Applicant: SAP SE

Inventor： Thomas Legler

IPC: G06F9/46 ,  G06F9/52 ,  G06F12/0817 ,  G06F16/25

CPC classification number: G06F9/467 ,  G06F9/52 ,  G06F12/0828 ,  G06F16/25

Abstract: A method may include determining a threshold quantity of attempts to optimistically perform a first transaction operating data stored in a database. The threshold quantity of attempts may be determined based on an expected workload of the first transaction and/or a workload at the database. The first transaction may be performed optimistically including by tracking cache lines accessed by the first transaction and detecting, based on a second transaction writing to a cache line accessed by the first transaction, a conflict between the first transaction and the second transaction. If the first transaction is not successful performed after the threshold quantity of attempts to optimistically perform the first transaction, the first transaction may be performed in a fallback mode including by acquiring a lock to prevent the second transaction from accessing a same data in the database as the first transaction. Related systems and articles of manufacture are also provided.

公开(公告)号：US20220261391A1

公开(公告)日：2022-08-18

申请号：US17733514

申请日：2022-04-29

Applicant: SAP SE

Inventor： Klaus Otto Mueller ,  Thomas Legler

IPC: G06F16/22 ,  G06F9/445 ,  G06F16/23 ,  G06F16/2458

Abstract: A system for unloading tables of a database is provided. In some aspects, the system performs operations including determining that a number of accesses to a table occurring within a time period has satisfied an access threshold. The operations may further include identifying, in response to the determining, a first timestamp indicating a most recent access to the table. The operations may further include determining whether a difference between a current timestamp and the first timestamp satisfies a first time threshold. The operations may further include comparing, in response to the difference satisfying the first time threshold, a ratio of the difference and a size of the table to a ratio threshold. The operations may further include unloading, in response to satisfying the ratio threshold, the table. The operations may further include adjusting, based on the feedback, the first time threshold and/or the ratio threshold.

公开(公告)号：US11347710B2

公开(公告)日：2022-05-31

申请号：US16890446

申请日：2020-06-02

Applicant: SAP SE

Inventor： Klaus Otto Mueller ,  Thomas Legler

IPC: G06F16/22 ,  G06F16/23 ,  G06F16/2458 ,  G06F9/445

Abstract: A system for unloading tables of a database is provided. In some aspects, the system performs operations including determining that a number of accesses to a table occurring within a time period has satisfied an access threshold. The operations may further include identifying, in response to the determining, a first timestamp indicating a most recent access to the table. The operations may further include determining whether a difference between a current timestamp and the first timestamp satisfies a first time threshold. The operations may further include comparing, in response to the difference satisfying the first time threshold, a ratio of the difference and a size of the table to a ratio threshold. The operations may further include unloading, in response to satisfying the ratio threshold, the table. The operations may further include adjusting, based on the feedback, the first time threshold and/or the ratio threshold.

公开(公告)号：US20210303533A1

公开(公告)日：2021-09-30

申请号：US16830645

申请日：2020-03-26

Applicant: SAP SE

Inventor： Thomas Legler

IPC: G06F16/22 ,  G06F16/25 ,  G06F16/2458 ,  G06F16/2457

Abstract: There is provided a method for compressing a first tree data structure. The method includes determining, by a processor, to compress a first tree data structure associated with a dictionary of a database management system. The method further includes compressing the first tree data structure to generate a compressed tree data structure. The compressing includes traversing, by the processor and in response to the determining, the first tree data structure on a lowest level. The compressing further includes identifying, by the processor and in response to traversing, empty nodes on the lowest level. The compressing further includes removing the identified empty nodes to compress the lowest level. The compressing further includes constructing, in response to the removing, a second level of the compressed tree data structure based on the compressed lowest level, the second level higher in the compressed tree data structure than the compressed lowest level.