Apparatus and method for aggregate indexes

A computer-readable medium having stored thereon sequences of instructions for storing aggregate information in an entry of a database index for a database table, the sequences of instructions including instructions which, when executed by a processor, cause the processor to perform the steps of:

• storing, in the entry that corresponds to a key value, information that indicates where two or more database table rows that have the key value are located in the database table;
• computing first aggregate information based on an aggregate operation and said two or more database table rows;
• and
• storing the first aggregate information in the entry.

A method for storing aggregate information in a first entry of a database index for a database table, comprising:

• storing, in the first entry that corresponds to a range of key values, information that indicates where two or more database table rows that have respective key values are located in the database table, wherein each of said key values is within the range of key values;
• computing first aggregate information based on an aggregate operation and said two or more database table rows;
• and
• storing the first aggregate information in the first entry.

A computer-readable medium having stored thereon sequences of instructions for storing aggregate information in a first entry of a database index for a database table, the sequences of instructions including instructions which, when executed by a processor, cause the processor to perform the steps of:

• storing, in the first entry that corresponds to a range of key values, information that indicates where two or more database table rows that have respective key values are located in the database table, wherein each of said key values is within the range of key values;
• computing first aggregate information based on an aggregate operation and said two or more database table rows;
• and
• storing the first aggregate information in the first entry.

A method for accessing aggregate information stored in an entry of a database index for a database table, comprising:

• storing, in the entry that corresponds to a key value, information that indicates where two or more database table rows that have the key value are located in the database table;
• receiving a database query requiring information based on said two or more database table rows;
• accessing aggregate information from the entry;
• and
• providing an aggregate value using the aggregate information.

A computer-readable medium having stored thereon sequences of instructions for accessing aggregate information stored in an entry of a database index for a database table, the sequences of instructions including instructions which, when executed by a processor, cause the processor to perform the steps of:

• storing, in the entry that corresponds to a key value, information that indicates where two or more database table rows that have the key value are located in the database table;
• receiving a database query requiring information based on said two or more database table rows;
• accessing aggregate information from the entry;
• and
• providing an aggregate value using the aggregate information.

A method for updating aggregate information in an entry of a database index for a database table, comprising:

• storing, in the entry that corresponds to a key value, information that indicates where two or more database table rows that have the key value are located in the database table;
• storing aggregate information in the entry;
• performing a database table operation related to the key value;
• and
• updating the aggregate information in accordance with the database table operation.

A computer-readable medium having stored thereon sequences of instructions for updating aggregate information in an entry of a database index for a database table, the sequences of instructions including instructions which, when executed by a processor, cause the processor to perform the steps of:

• storing, in the entry that corresponds to a key value, information that indicates where two or more database table rows that have the key value are located in the database table;
• storing aggregate information in the entry;
• performing a database table operation related to the key value;
• and
• updating the aggregate information in accordance with the database table operation.