Sap Se

Sap Ag

Martin Richtarsky

Ivan Schreter

Christian Bensberg

Franz Faerber

Guenter Radestock

Frederik Transier

Kai Stammerjohann

Klaus Nagel

Carsten Thiel

Bernhard Scheirle

Achim Seubert

Juchang Lee

A method, a system and a computer program product for execution of queries. A first query is executed using a first query execution plan to generate a first result data by applying a first query operator to a first data stored in a first storage location. The first result data is provided to a second query execution plan for execution of a second query. The second query is executed on a second data stored in a second storage location in accordance with the second query execution plan. The second query execution plan includes a second query operator. Based on the execution of the second query, a second result data is generated in accordance with the second query execution plan by at least applying the second query operator to at least the provided first result data.

Query plan sharing

The subject matter described herein relates to implementation of a dictionary in a column-based, in-memory database where values are not stored directly, rather, for each column, a dictionary is created with all distinct values. For each row, a reference to the corresponding value in the dictionary is stored. In one aspect, data is stored in a memory structure organized in a column store format defined by a plurality of columns and a plurality of rows. A dictionary for each column in the memory structure is generated. The dictionary has distinct values for each column. A reference to the dictionary is generated for each column in the memory structure. The dictionary and the reference to the dictionary are stored in the memory structure.

Fixed string dictionary

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

Conversion of a snowflake-like schema to a star-like schema includes a distribution of the snowflake-like schema across several host computer systems. Each host computer system has a fragment of the snowflake-like schema, including a fragment of constituent fact tables. Dimension keys in the fact table fragments are mapped to data tables via the constituent dimension tables. Data table keys are identified and populate the fact table for the converted star-like schema, thus obviating the dimension tables in the converted star-like schema.

Classic to in-memory cube conversion

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Bad Schoenborn, Germany

Martin Richtarsky