Estimating rows returned by recursive queries using fanout
US9002825B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2013 |
| Grant date | Apr 7, 2015 |
| Priority date | — |
| Expiry date | Apr 24, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/24545
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In an embodiment, a recursive query is received that comprises a first select statement with a seed select statement and a second select statement with a recursive reference, wherein the recursive query further identifies at least two columns in at least one table, wherein the at least two columns have parent-child relationships represented by nodes in a graph, wherein the graph represents the organization of values in rows in the at least one table. A target recursion depth is calculated for the graph based on a fanout of the graph. In an embodiment, the target recursion depth is calculated by summing the fanout at each recursion depth of the graph multiplied by a number of nodes at each recursion depth of the graph. An estimated number of rows that the recursive query will return is estimated based on the target recursion depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.