SAP SE
In-place load unit conversion

Abstract:

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.