Abstract: Data replication in a database includes identifying a source database system. The source database includes a main index file and a delta log file. To create a replica, one or more symbolic links to the source database system are generated. The symbolic links identify a path to a physical location of the source database. A replica of the source database is generated based on the symbolic links. The replica includes a copy of the main index file and delta log file. Information associated with the replica and the symbolic links is stored in a recovery log. Replica are provided transparently to most database engine components by re-using partitioning infrastructure. Components “see” replica as tables with a single partition; that partition is a local replica.

Abstract: Data replication in a database includes identifying a source database system. The source database includes a main index file and a delta log file. To create a replica, one or more symbolic links to the source database system are generated. The symbolic links identify a path to a physical location of the source database. A replica of the source database is generated based on the symbolic links. The replica includes a copy of the main index file and delta log file. Information associated with the replica and the symbolic links is stored in a recovery log. Replica are provided transparently to most database engine components by re-using partitioning infrastructure. Components “see” replica as tables with a single partition; that partition is a local replica.

Abstract: A method is disclosed for modeling application-level objects in terms of join graphs defined over tables containing structured data residing in a relational database. In accordance with the disclosed metamodel, each object is modeled logically as a join graph. A query received from an application that requests the return of objects meeting certain conditions is reformulated to refer to the metamodel. The metamodel includes an index structure having a plurality of indexes and a set of join conditions that specify relationships between the indexes. Some series of join conditions form join paths, such that each join path originates on an anchor table and ends on a table corresponding to one of the plurality of indexes. The metamodel further includes at least one view representing a subgraph of the join graph having at least one anchor table as a key.

Abstract: Systems and techniques for mapping data structures in a data processing environment to help ensure the accessibility of stored information. In one implementation, an article includes a machine-readable medium storing instructions. The instructions are operable to cause one or more machines to perform operations. The operations include receiving a first data storage schema in which a characteristic in a first dimension table is mapped by a first table and a second table and generating a second data storage schema. The first table maps the characteristic to a first object that include attributes to which time information is irrelevant to data processing activities and the second table maps the characteristic to a second object that include attributes to which time information is relevant to data processing activities.

Abstract: A query having multiple parts may be processed to form an intermediate results set. This intermediate results set may be partitioned into a plurality of groups. Thereafter, the groups may be sorted into a plurality of containers so that each container contains data sufficient to calculate one requested result in the multipart query. Related techniques, apparatuses, systems, and computer program products are also described.