Rewriting a query in terms of a summary based on functional dependencies and join backs, and based on join derivability

A method of processing queries, the method comprising the steps of:

• receiving a query that does not reference a particular materialized aggregate view;
• said materialized aggregate view specifying an outer join between a child table and a parent table;
• said query specifying a particular type of join between said child table and said parent table, wherein said particular type of join is one of an inner join, an anti-join and a semi-join;
• and
• rewriting said query to produce a rewritten query that accesses said materialized aggregate view to produce data required by said query.

A method of processing queries, the method comprising the steps of:

• receiving a query that does not reference a particular materialized aggregate view;
• said materialized aggregate view specifying an inner join between a child table and a parent table;
• said query specifying a semi-join between said child table and said parent table;
• and
• rewriting said query to produce a rewritten query that accesses said materialized aggregate view to produce data required by said query.

A method for processing queries, the method comprising the steps of:

• receiving a query that does not reference a particular materialized view;
• said query specifying that results are to be grouped by a first set of one or more columns;
• said materialized view reflecting data that is grouped by a second set of one or more columns;
• determining whether each column in said first set of columns either
• a) exactly matches a column in said second set of columns,
• b) is functionally dependent on another column in said first set of columns, or
• c) is functionally dependent on a column in said second set of columns;
• if each column in said first set of columns either exactly matches a column in said second set of columns, is functionally dependent on another column in said first set of columns, or is functionally dependent on a column in said second set of columns, then rewriting said query to produce a rewritten query that references said materialized view.

A computer-readable medium carrying one or more sequences of instructions for processing queries, 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 query that does not reference a particular materialized view;
• said query requiring access to values from a particular column not contained in said materialized view;
• determining whether the particular materialized view satisfies each condition in a set of conditions, the set of conditions at least including a condition that said particular column is functionally dependent on a column that does belong to said materialized view;
• and
• if said materialized view satisfies each condition in said set of conditions, then rewriting said query to produce a rewritten query that references said materialized view and joins said materialized view back to a join-back table that contains said particular column.

A computer-readable medium carrying one or more sequences of instructions for processing queries, 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 query that does not reference a particular materialized aggregate view;
• said materialized aggregate view specifying an outer join between a child table and a parent table;
• said query specifying a particular type of join between said child table and said parent table, wherein said particular type of join is one of an inner join, an anti-join and a semi-join;
• and
• rewriting said query to produce a rewritten query that accesses said materialized aggregate view to produce data required by said query.

A computer-readable medium carrying one or more sequences of instructions for processing queries, 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 query that does not reference a particular materialized aggregate view;
• said materialized aggregate view specifying an inner join between a child table and a parent table;
• said query specifying a semi-join between said child table and said parent table;
• and
• rewriting said query to produce a rewritten query that accesses said materialized aggregate view to produce data required by said query.

A computer-readable medium carrying one or more sequences of instructions for processing queries, 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 query that does not reference a particular materialized view;
• said query specifying that results are to be grouped by a first set of one or more columns;
• said materialized view reflecting data that is grouped by a second set of one or more columns;
• determining whether each column in said first set of columns either
• a) exactly matches a column in said second set of columns,
• b) is functionally dependent on another column in said first set of columns, or
• c) is functionally dependent on a column in said second set of columns;
• if each column in said first set of columns either exactly matches a column in said second set of columns, is functionally dependent on another column in said first set of columns, or is functionally dependent on a column in said second set of columns, then rewriting said query to produce a rewritten query that references said materialized view.