US 7,127,467 B2 · Managing expressions in a database system

Abstract

A method for managing expressions includes receiving a first query that includes a first conditional expression. The first expression is then represented as data in a column of a table. A second query is received that specifies a first set of criteria, and the second query is executed to select data based at least on whether expressions in the column satisfy the first set of criteria. In an embodiment, the second query further specifies a second set of criteria, wherein executing the second query includes selecting data based on whether data in columns other than the expression column satisfy the second criteria. A special index is defined, which can be created on the column that stores the expressions as data, to filter large sets of expressions efficiently. A method of evaluating an expression set stored as data in a table classifies each predicate from each expression, and filters the expression set based on the predicate classification.

Claims37

Dependent claims

A computer-implemented method for managing expressions in a database, the method comprising the steps of:

receiving a first query that includes an expression that defines a first condition relating to a first attribute;
representing the first condition as data in a column of a row of a table;
storing a first value in association with the data, wherein the first value relates to a second attribute;
receiving a second query that specifies a second value associated with the first attribute and a second condition relating the second attribute;
and
executing the second query, wherein executing the second query includes reading, from the column of the row, the data representing the first condition;
determining whether the second value satisfies the first condition;
reading the first value associated with the data;
determining whether the first value satisfies the second condition;
and
selecting data to answer the second query based at least on whether the second value satisfies the first condition, and the first value satisfies the second condition.

8 more elements

A computer-implemented method for evaluating an expression set that is stored as data in a column of a table, the method comprising the steps of:

classifying each predicate from each expression of the expression set as one of,
an indexed attribute predicate, wherein a bitmap index is created based on a set of operator and constant attributes that are stored in respective columns of a predicate table in association with a respective predicate identifier;
a stored attribute predicate, wherein a set of operator and constant attributes are stored in respective columns of the predicate table in association with a respective predicate identifier, and wherein no index is created on the set of operator and constant attributes;
a sparse predicate, in which a predicate identifier associated with a sparse predicate is uncommon in the expression set, and wherein a sparse predicate is stored as data in the predicate table;
and
filtering the expression set based on the classification of predicates from the expression set.

3 more elements

A computer-readable storage medium carrying one or more sequences of instructions for evaluating an expression set that is stored as data in a column of a table, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

classifying each predicate from each expression of the expression set as one of,
an indexed attribute predicate, wherein a bitmap index is created based on a set of operator and constant attributes that are stored in respective columns of a predicate table in association with a respective predicate identifier;
a stored attribute predicate, wherein a set of operator and constant attributes are stored in respective columns of the predicate table in association with a respective predicate identifier, and wherein no index is created on the set of operator and constant attributes;
a sparse predicate, in which a predicate identifier associated with a sparse predicate is uncommon in the expression set, and wherein a sparse predicate is stored as data in the predicate table;
and
filtering the expression set based on the classification of predicates from the expression set.

3 more elements

A computer-readable storage medium carrying one or more sequences of instructions for managing expressions in a database, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

receiving a first query that includes an expression that defines a first condition relating to a first attribute;
representing the first condition as data in a column of a row of a table;
storing a first value in association with the data, wherein the first value relates to a second attribute;
receiving a second query that specifies a second value associated with the first attribute and a second condition relating to the second attribute;
and
executing the second query, wherein executing the second query includes reading, from the column of the row, the data representing the first condition;
determining whether the second value satisfies the first condition;
reading the first value associated with the data;
determining whether the first value satisfies the second condition;
and
selecting data to answer the second query based at least on whether the second value satisfies the first condition, and the first value satisfies the second condition.

8 more elements

Dependencies are inferred from the claim text.

Managing expressions in a database system

Life of this patent

Managing expressions in a database system

Life of this patent

Abstract

Claims37