Sap Se

Bernhard Scheirle

Guenter Radestock

Carsten Thiel

Thomas Legler

Rolando Blanco

Sebastian Seifert

Robert Schulze

Amit Pathak

Martin Heidel

Andreas Tonder

Joern Schmidt

Janardhan Hungund

Mihnea Andrei

Norman May

Thomas Peh

Werner Thesing

Muhammed Sharique

Christian Lemke

Kai-Uwe Sattler

Robert Lasch

Deepak Shrivastava

Souvik Pal

Surendra Vishnoi

Martin Richtarsky

Amit Saonerker

Neha Shikha Kachhap

Jagadeesha Kanihal

Kantikumar Kantikumar

Amit Sankhla

A database system detects a query targeting a first database object stored in a unified persistence format in a persistence store, where a first load unit is specified for loading the first database object into an in-memory store. The database system determines whether to convert the first load unit to a second load unit based on one or more conditions. In response to determining to convert the first load unit to the second load unit for the first database object, the first database object is loaded into the in-memory store according to the second load unit without performing a rewrite of the first database object in the persistence store. In an example, the first load unit is a column-loadable unit and the second load unit is a page-loadable unit.

Load unit conversion with unified persistence

A method may include receiving a first transaction inserting a record into a database and a second transaction deleting the record from the database. A validity period for the record may be determined based on a first commit time at which the first transaction is committed and a second commit time at which the second transaction is committed. A current table and/or a history table of a system versioned table may be updated to include the record based on the validity period of the record. One or more temporal operations may be performed based on the system versioned table. For example, a time travel operation may be performed to retrieve, based on the system versioned table, one or more records that are valid at a given point in time. Related systems and computer program products are also provided.

System versioned table with transactional system time

A primary database system loads database objects into a primary in-memory store according to a given format. The primary database captures, in replay logs, the loading of the database objects according to the given format. The primary database sends the replay logs to a secondary database system. In response to receiving a replay log, the secondary database checks the value of a log replay configuration parameter. If the configuration parameter is a first value, the secondary database replays the replay log to load the corresponding database objects into a secondary in-memory store according to a first format. If the configuration parameter is a second value, the secondary database replays the log to load the objects according to a second format, and if the configuration parameter is a third value, the secondary database replays the log to load the objects in a same format which was used by the primary database.

Database load unit for replication log replay

Embodiments of the present disclosure include techniques for cooperative memory management. In one embodiment, a database management system includes a memory manager for managing a memory buffer. The memory buffer is configured to allocate memory to table data and temporary data dynamically. In some embodiments, table data memory allocations are reduced and temporary data memory allocations are increased to process queries. Temporary data memory allocations may be increased to store temporary data associated with one or more portions of a query. The memory buffer reallocates table data memory allocations and temporary data memory allocations as needed to more efficiently use available memory.

Cooperative memory management in database management systems

A system includes storage, in a volatile random access memory, of a first data block comprising an array of distinct values of a database table column, and first header data comprising a first pointer to the first data block, determination of a memory size associated with the first header data and the first data block, allocation of a first memory block of the non-volatile random access memory based on the determined memory size, determination of an address of the non-volatile random access memory associated with the allocated first memory block, and writing of an indicator of the number of distinct values of the array and a binary copy of the first data block at the address of the non-volatile random access memory.

Storage of database dictionary structures in non-volatile memory

A system includes a volatile random access memory storing first header data and a first data block, the first header data including descriptive information and a first pointer to the first data block, and a non-volatile random access memory. The system includes determination of a memory size associated with the first header data and the first data block, allocation of a first memory block of the non-volatile random access memory based on the determined memory size, determination of an address of the non-volatile random access memory associated with the allocated first memory block, and writing of the descriptive information and a binary copy of the first data block at the address of the non-volatile random access memory.

Storage of data structures in non-volatile memory

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Walldorf, Germany

Bernhard Scheirle