Apparatus and method for computing n-way co-occurrences of data tuples in scalar indexes
A non-transitory computer readable storage medium includes executable instructions to receive primary matched values with corresponding document identifications. The primary matched values correspond to a specified primary value, for example expressed in a search query. A secondary scalar index is scanned to match the document identifications with secondary matched values with corresponding secondary values. A tertiary scalar index is scanned to match the document identifications with tertiary matched values with corresponding tertiary values. The secondary values and tertiary values are provided as tuples. Each tuple has the specified primary value, a secondary value, a tertiary value and frequency indicia.
1. A non-transitory computer readable storage medium, comprising executable instructions to:
receive primary matched values with corresponding document identifications, wherein the primary matched values correspond to a specified primary value;
scan a secondary scalar index to match the document identifications with secondary matched values with corresponding secondary values;
scan a tertiary scalar index to match the document identifications with tertiary matched values with corresponding tertiary values; and
provide the secondary values and tertiary values as tuples, where each tuple has the specified primary value, a secondary value, a tertiary value and frequency indicia;
wherein the secondary scalar index and the tertiary scalar index are each a two column index with a document identifications column and a values column to facilitate mappings of document identifications to values and vice versa.
2. The non-transitory computer readable storage medium of claim 1 wherein the secondary value and the tertiary value are different scalar types.
3. The non-transitory computer readable storage medium of claim 1 wherein the frequency indicia includes a null value.
4. The non-transitory computer readable storage medium of claim 1 wherein scanning of the secondary scalar index is modified in response to a query constraint.
5. A non-transitory computer readable storage medium, comprising executable instructions to:
receive a plurality of scalar indexes, wherein each scalar index is a two column index with a document identifications column and a values column to facilitate mappings of document identifications to values and vice versa;
chain through the plurality of scalar indexes using a document identification value to produce sub-tuples; and
combine the sub-tuples to form tuples responsive to a query, wherein the tuples comprise values from the values columns of the plurality of scalar indexes.
6. The non-transitory computer readable storage medium of claim 5 wherein the tuples include at least a first value, a second value and frequency indicia.
7. The non-transitory computer readable storage medium of claim 6 wherein the frequency indicia includes a null value.
8. The non-transitory computer readable storage medium of claim 6 wherein the first value and the second value are different scalar types.
9. The non-transitory computer readable storage medium of claim 5 wherein the executable instructions to chain observe a query constraint.