Abstract: In one aspect, a method may include receiving a query associated with a plurality of data sources, wherein the query includes a first attribute; identifying that a query operator, which is associated with execution of the query and the first attribute, includes a first input from a first data source of the plurality of data sources and a second input from a second data source of the plurality of data sources; determining that the first attribute at the second data source corresponds to null; pruning, based on the determined null, the second input from the second data source to inhibit a select from the second data source; and in response to the pruning, performing the query operator by selecting, from the first data source, a column corresponding to the first attribute. Related systems, methods, and articles or manufacture are also disclosed.

Abstract: Testing a database replication system within a multi-container system architecture comprises receiving a first request for creating a database recovery system within a multi-container system architecture. The multi-container system architecture is configured to contain a plurality of tenant databases and a system database, and the database recovery system includes a primary system and a secondary system. The primary system is then identified from the information in the first request. Upon identification, a first tenant database included in the plurality of tenant databases is determined that corresponds to the identified primary system. Upon determining the first tenant database, a second tenant database of the plurality of tenant database is generated that corresponds to the secondary system, and which is enabled to test replicating information that would otherwise be associated with the first tenant database. Related apparatus, systems, techniques and articles are also described.

Abstract: Testing a database replication system within a multi-container system architecture comprises receiving a first request for creating a database recovery system within a multi-container system architecture. The multi-container system architecture is configured to contain a plurality of tenant databases and a system database, and the database recovery system includes a primary system and a secondary system. The primary system is then identified from the information in the first request. Upon identification, a first tenant database included in the plurality of tenant databases is determined that corresponds to the identified primary system. Upon determining the first tenant database, a second tenant database of the plurality of tenant database is generated that corresponds to the secondary system, and which is enabled to test replicating information that would otherwise be associated with the first tenant database. Related apparatus, systems, techniques and articles are also described.