Abstract: Methods, systems and program products for query optimization using sideways information passing. In one implementation, a join clause in a query is identified that specifies an outer table of tuples to be joined with an inner table, the outer table having one or more attributes, and each of the attributes of the outer table having values stored in an attribute file that is distinct from attribute files in which the values of other attributes are stored. A plan for the query is created which, when executed, causes selection of a subset of tuples of the outer table to serve as input to the join clause in place of the outer table based on one or more predicates applied to the inner table.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for operating on time sequences of data. In one aspect, a method includes a database management system storing and updating information in records in a table of a database, the records being associated with respective times that are spaced apart by time intervals, the database management system responding to a query that is phrased to imply a putative record with respect to a time interval that is not among the time intervals with which the records of the table are associated, and the response of the database management system to the query including a computation of a value of an attribute of the putative record from at least one non-null value of the attribute for one of the records of the table, the computation being based on an interpolation policy.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a database designer and a database storage designer. In one aspect, a method includes creating a set of candidate projections and progressively narrowing the set of candidate projections and a set of queries by eliminating candidate projections that do not satisfy a performance improvement criterion for remaining queries based on the properties associated with the candidate projections.