Sap Se

Sap Global IP Group

Deepak Shrivastava

Janardhan Hungund

Mihnea Andrei

Amit Pathak

Edward-Robert Tyercha

Sebastian Seifert

Souvik Pal

Amit Saonerker

Ivan Schreter

Colin Florendo

Robert Schulze

Michael Muehle

Rolando Blanco

Chaitanya Gottipati

Muhammed Sharique

Bernhard Scheirle

Kantikumar Kantikumar

Awisha Makwana

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

Computer-implemented methods, systems and products, the method comprising receiving, at a data server associated with a database, a command for data transfer between a client machine and the data server over a communications network, the data being stored in at least a data table comprising one or more columns; in response to receiving the command for data transfer, determining whether one or more columns of the data table are designated; identifying the one or more designated columns, such that data associated with the one or more designated columns is either considered or not considered for purpose of the data transfer; and executing the command to transfer the data in the database according to the designated columns.

Data transfer in a computer-implemented database

Disclosed herein are system, method, and computer program product embodiments for converting column loadable data in a database into a page loadable format. When a column oriented in-memory database needs to perform an operation on a table, the affected columns must be loaded fully into memory. In some cases, a database may partition tables, allowing for column fragments corresponding to those partitions to be loaded into memory. These column fragments may exceed available memory, such that it is beneficial to convert the column fragment into a page loadable format. Approaches are discussed herein for performing the conversion without the need to update global metadata during the process, allowing for multiple parallel column fragments to be updated, allowing data manipulation language (DML) operations to continue on the column during the conversion process, and reducing the impact of blocked parallel savepoint operations during the conversion process by chunking the conversion process.

In-place load unit conversion

Disclosed herein are system, method, and computer program product embodiments for exporting and importing database tables in a database management system using multi-version concurrency control (MVCC). An embodiment operates by first initiating an export of a database table in the database management system. During the export transaction, temporary creation and deletion timestamps are identified from MVCC information associated with each row in the database table. Each temporary timestamp is associated with a database transaction. A timestamp map is then generated that associates the identified temporary timestamps with commit timestamps of the associated transactions. The database table, associated MVCC information, timestamp map, and snapshot timestamp of the export transaction are written to a binary file. When an import of the database table is initiated in a database management system, the database table is reconstructed from the table rows, associated MVCC information, timestamp map, and snapshot timestamp of the export transaction in the binary file.

Exporting and importing database tables in a multi-user database environment

Growing community of inventors

Pune, India

Deepak Shrivastava