Abstract: Various aspects of the subject technology relate to methods, systems, and machine-readable media for generating histograms according to a set-theoretic approach. The method includes receiving a command to generate at least one histogram from selected data, the selected data comprising a plurality of column groups. The method also includes identifying a superset from the plurality of column groups. The method also includes materializing, in a memory, a superset multi-column group for the superset. The method also includes identifying at least one subset of the superset from the plurality of column groups, the at least one subset comprising at least one column group. The method also includes processing the at least one subset of the superset to form a grouped resultset. The method also includes generating the at least one histogram for the grouped resultset of the at least one subset of the superset.

Abstract: Various aspects of the subject technology relate to methods, systems, and machine-readable media for generating histograms according to a set-theoretic approach. The method includes receiving a command to generate at least one histogram from selected data, the selected data comprising a plurality of column groups. The method also includes identifying a superset from the plurality of column groups. The method also includes materializing, in a memory, a superset multi-column group for the superset. The method also includes identifying at least one subset of the superset from the plurality of column groups, the at least one subset comprising at least one column group. The method also includes processing the at least one subset of the superset to form a grouped resultset. The method also includes generating the at least one histogram for the grouped resultset of the at least one subset of the superset.

Abstract: Systems and methods for producing histograms are disclosed. One method for producing a histogram includes processing a database table to produce a grouped result set, and dividing the grouped result set into a plurality of collections with each collection containing one or more intervals of the grouped result set. Further, for each collection containing one or more intervals, the method includes determining one or more statistical parameters characterizing a distribution of the data within the collection. Still further, for each collection, the method includes applying one of a plurality of different histogram-producing algorithms based on the one or more statistical parameters to produce a histogram such that at least two of the different histogram-producing algorithms are used to render a respective different portion of the histogram.

Abstract: Systems and methods for producing histograms are disclosed. One method for producing a histogram includes processing a database table to produce a grouped result set, and dividing the grouped result set into a plurality of collections with each collection containing one or more intervals of the grouped result set. Further, for each collection containing one or more intervals, the method includes determining one or more statistical parameters characterizing a distribution of the data within the collection. Still further, for each collection, the method includes applying one of a plurality of different histogram-producing algorithms based on the one or more statistical parameters to produce a histogram such that at least two of the different histogram-producing algorithms are used to render a respective different portion of the histogram.

Abstract: A method of performing a database join includes receiving a query. The query may specify a join of a first table and a second table. The method further includes determining a new predicate based on a mapping between a first column of the first table and a second column of the second table for a plurality of tuples of the join. Further, the method includes modifying the query such that the query comprises the new predicate.

Abstract: A method of performing a database join is provided herein. The method includes receiving a query. The query may specify a join of a first table and a second table. The method further includes determining a new predicate based on a mapping between a first column of the first table and a second column of the second table for a plurality of tuples of the join. Further, the method includes modifying the query such that the query comprises the new predicate.