Abstract: According to one or more embodiments of the present invention, a computer-implemented method includes creating a hybrid index for a multi-zone data storage system in which a first zone has data that is organized for transaction processing, and a second zone that has data organized for analytic processing. Each index entry in the hybrid index includes an index key including an equality column, a begin-timestamp column, and a tuple-sequence-number column. The method further includes building an index run to be included in the hybrid index, the index run includes multiple index entries. An index run is created by selecting columns by scanning data blocks from the first zone, computing tuple-sequence-number values for the index entries to be included in the hybrid index, and sorting the index entries according to a predetermined order using the columns to be included in the index run.

Abstract: According to one or more embodiments of the present invention, a computer-implemented method includes creating a hybrid index for a multi-zone data storage system in which a first zone has data that is organized for transaction processing, and a second zone that has data organized for analytic processing. Each index entry in the hybrid index includes an index key including an equality column, a begin-timestamp column, and a tuple-sequence-number column. The method further includes building an index run to be included in the hybrid index, the index run includes multiple index entries. An index run is created by selecting columns by scanning data blocks from the first zone, computing tuple-sequence-number values for the index entries to be included in the hybrid index, and sorting the index entries according to a predetermined order using the columns to be included in the index run.

Abstract: Data flow in a database statement for a database management system having memory storing a database is simplified. The statement has at least two sequenced subexpressions, evaluation of which is driven by a sequencing operation. A reference to a first sequenced subexpression in a second sequenced subexpression subsequent to the first sequenced subexpression is determined. The reference affirming evaluation of the first sequenced subexpression is determined. A first evaluation order for conflicting table accesses between the first sequenced subexpression and other table accesses in the statement is determined. A second evaluation order between the other table accesses and the determined reference is also determined. The sequencing operation for the first sequenced subexpression is modified based on a sequential arrangement of the determined reference and the first sequenced subexpression according to the first evaluation order and the second evaluation order.

Abstract: Disclosed is a method and system for incrementally maintaining algebraic functions in automatic summary tables (ASTs) of at least one relational database. The method associates a work area with each algebraic function in each AST. Each work area is comprised of one or more variables. The method populates the variables within each work area for each algebraic function when each AST is created and when each AST is updated. The method maintains each work area by adding and subtracting to and from its associated variables when the associated data changes in the relational database. The functions that compute the variables of the work areas are distributive and thus incrementally maintainable. The method computes and recomputes the algebraic function within an AST after the updates have changed one or more of the variables of its workarea.