Sap Se

Sebastian Seifert

Christian Lemke

Amit Pathak

Mihnea Andrei

Robert Schulze

Colin Florendo

Reza Sherkat

Janardhan Hungund

Bernhard Scheirle

Souvik Pal

Adrian Dragusanu

Deepak Shrivastava

Frederic Junker

Amit Saonerker

Ivan Schreter

Christoph Weyerhaeuser

Boris Gruschko

Guenter Radestock

Christian Mohr

Martin Strenge

Thomas Peh

Rolando Blanco

Werner Thesing

Frederik Transier

Helmut Prestel

Reiner Singer

Muhammed Sharique

Carsten Thiel

Rolf Hammer

Kai Baumgarten

Guo Gang Ye

Surendra Vishnoi

Sigrid K Wortmann

Philipp Grosse

Yu Su

Veit Spaegele

Thomas Elvers

Junhui Liu

Juan Ge

Jianfeng Yan

Santhosh T Kumar

Anish Maniyar

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 database system detects an operation to move a first database object from an in-memory store to a persistence store, wherein the first database object is in either a page-loadable or column-loadable format in the in-memory store, and wherein the first database object comprises a plurality of subcomponents. Each subcomponent of the first database object is examined separately from other subcomponents of the plurality of subcomponents. In response to determining that a first subcomponent of the plurality of subcomponents has a datatype and a compression type supported by a unified persistence format, the first subcomponent is stored in a unified persistence format in the persistence store. In response to determining that a second subcomponent of the plurality of subcomponents has either a datatype or a compression type which is not supported by the unified persistence format, the second subcomponent is stored in a serial persistence format in the persistence store.

Unified persistence overall feature

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

A database system detects a query targeting a first database object stored in a unified persistence format in a persistence store. In response to detecting the query, the database system determines whether to load the first database object in column-loadable format or page-loadable format into an in-memory store. In response to determining to load the first database object in the column-loadable format, the database system determines if a first bit representation of one or more corresponding primitives in the persistence store is compatible with a second bit representation used for storing the primitives in the in-memory store. The database system performs a native copy operation to copy the primitives from the persistence store to the in-memory store if the bit representations are compatible, where the native copy operation involves copying the primitives on a page-by-page basis without decoding and encoding values of the one or more primitives.

Native copy mechanism for in-memory and paged primitive data structures

Systems and methods include reception of an instruction to perform a consistency check on compressed column data. In response to the instruction, a compression algorithm applied to uncompressed column data to generate the compressed column data is determined, one or more consistency checks associated with the compression algorithm are determined, wherein a first one or more consistency checks associated with a first compression algorithm are different from a second one or more consistency checks associated with a second compression algorithm, the one or more consistency checks are executed on the compressed column data, and, if the one or more consistency checks are not satisfied, a notification is transmitted to a user.

Consistency checks for compressed data

Disclosed herein are system, method, and computer-program product embodiments for generating a paged and in-memory representation of a database object. An embodiment operates by maintaining in-memory and paged form primitives unique to the database object or a substructure thereof in a database such that the in-memory and paged form primitives are capable of providing the in-memory and paged representations of the database objects, respectively. Thereafter, a load configuration for the database object is determined. Based on the load configuration, the in-memory and/or paged representations of the database object are generated using the in-memory form primitive or the paged form primitive unique to the database object, respectively. Subsequently, the in-memory and/or paged representations of the database object are stored in the database.

Hybrid column store providing both paged and memory-resident configurations

A system includes application of respective compression types to first data associated with each of a plurality of columns to generate compressed column data, determination of a first compression ratio for each of the plurality of columns based on the compressed column data, storage of the determined first compression ratios, application, for each of the plurality of columns, of the determined compression type to second data associated with the column to generate second compressed column data, determination of a second compression ratio for each of the plurality of columns based on the second compressed column data, determination of a value for each column based on the stored first compression ratio and the second compression ratio determined for the column, determination of a representative value of the determined values, and determination, based on the representative value, whether to re-determine a compression type for each of the plurality of columns.

Compression determination for column store

A system in which a volatile random access memory stores first header data, second header data, a first logical array in a first contiguous memory block and a second logical array in a second contiguous memory block. Each array position of the first logical array stores a database column value, and each array position of the second logical array stores an indication of a number of consecutive occurrences of a database column value. The first header data includes a first pointer to the first memory block, and the second header data includes a second pointer to the second memory block. A memory size is determined associated with the first header data, the second header data, the first memory block, and the second memory block, a first memory block of the non-volatile random access memory is allocated based on the determined memory size, an address of the random access memory associated with the allocated first memory block is determined, and a portion of the first header data, a portion of the second header data, a binary copy of the first memory block and a binary copy of the second memory block are written at the address of the random access memory.

Storage of run-length encoded database column data 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

A method can include: reordering an enriched inverted index associated with a database, the enriched inverted index including a first inverted list having a first plurality of current document identifiers of records that contain a first data value, the enriched inverted index further including a first data structure storing enrichment data, the reordering of the enriched inverted index comprising: generating an ordinal sequence corresponding to an order of a first plurality of current document identifiers that include a change of at least one of the first plurality of current document identifiers to a new document identifier; determining a reordered ordinal sequence corresponding to a sorted order of the second plurality of document identifiers; separately reordering, based at least on the reordered ordinal sequence, the first plurality of current document identifiers in the first inverted list and the enrichment data in the first data structure.

Reordering of enriched inverted indices

Disclosed herein are system and method embodiments for generating a paged inverted index. An embodiment is generated by storing a first data structure and the second data structure in a plurality of pages, where the plurality of pages are stored in the one or more memories. The first data structure is stored in the plurality of pages and includes a plurality of value identifiers, where a value identifier corresponds to an offset. The second data structure stored in the plurality of pages includes a plurality of row positions, wherein a row position is at a location that corresponds to the offset in the first data structure and identifies a position of row in a table that stores data associated with the value ID.

Paged inverted index

Methods and apparatus, including computer program products, are provided for implementing a cooperative model between an application and a database. In one aspect, there is provided a computer-implemented method. The method may include receiving from an application a command to perform an operation at a database; accessing metadata representative of the application; configuring, based on at least the metadata, a result of the operation; and sending the configured result to shared memory accessible by the application. Related apparatus, systems, methods, and articles are also described.

Cooperative model between an application server and a database

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Heidelberg, Germany

Sebastian Seifert