Processing XML data stream(s) using continuous queries in a data stream management system

• US 20080120283A1
• Filed: 11/17/2006
• Published: 05/22/2008
• Est. Priority Date: 11/17/2006
• Status: Abandoned Application

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Mishra, Shailendra K., Krishnaprasad, Muralidhar, Liu, Zhen Hua
• Application Number:
  US11/601,415
• Publication Number:
  US 20080120283A1
• Time in Patent Office: Days
• US Class Current: 707/4
• CPC Class Codes: G06F 16/83 Querying

Abstract

A computer is programmed to accept queries over streams of, data structured as per a predetermined syntax (e.g. defined in XML). The computer is further programmed to execute such queries continually (or periodically) on data streams of tuples containing structured data that conform to the same predetermined syntax. In many embodiments, the computer includes an engine that exclusively processes only structured data, quickly and efficiently. The computer invokes the structured data engine in two different ways depending on the embodiment: (a) directly on encountering a structured data operator, or (b) indirectly by parsing operands within the structured data operator which contain path expressions, creating a new source to supply scalar data extracted from structured data, and generating additional trees of operators that are natively supported, followed by invoking the structured data engine only when the structured data operator in the query cannot be fully implemented by natively supported operators.

Claims

1. A computer-implemented method of processing streams of structured data using continuous queries in a data stream management system, the method comprising:

receiving a continuous query;

parsing the continuous query to identify an operator on data structured in accordance with a predetermined syntax;

inserting in a representation of the continuous query, a function to invoke a processor of structured data for said operator;

generating a plan, based on said representation, for execution of the continuous query including invocation of said processor; and

invoking the processor during execution of the continuous query using said plan, in response to receipt of said data in a stream of structured data.

2. The method of claim 1 further comprising:

parsing a path into structured data, said path being present in an operand of said operator;

creating a new source to supply scalar data extracted from the structured data;

generating an additional tree for an expression in the continuous query that operates on structured data, using scalar data supplied by said new source; and

modifying an original tree of operators that includes said operator, by linking the additional tree, thereby to yield a modified tree;

wherein the plan for execution of the query is generated based on the modified tree.

3. A carrier wave encoded with instructions to perform the acts of receiving, parsing, inserting, generating and invoking as recited in claim 1.

4. A computer-readable storage medium encoded with instructions to perform the acts of receiving, parsing, inserting, generating and invoking as recited in claim 1.

5. A computer-implemented method of processing streams of structured data using continuous queries in a data stream management system, the method comprising:

receiving a continuous query;

parsing the continuous query to identify an operator to convert an input stream of structured data into at least one output stream of scalar data;

inserting in a representation of the continuous query, a stream source representing said operator and having a row function and a column function;

generating a plan, based on said representation, for execution of the continuous query including invocation of a processor; and

invoking the processor during execution of the continuous query, in response to receipt of said data in a stream of structured data, by using the row function to process a path into structured data in said input stream, and using the column function to supply scalar data on said at least one output stream.

6. A computer-implemented method of processing streams of structured data using continuous queries in a data stream management system, the method comprising:

receiving a continuous query;

parsing the continuous query to identify an operator to convert an input stream of structured data into an output stream of structured data;

invoking a structured query compiler to compile the operator and build a transform function into an operator tree by applying a transformation to structured data;

linking to a tree representation of the continuous query, said operator tree obtained from said invoking to obtain a modified tree;

generating a plan, based on said modified tree, for execution of the continuous query including invocation of a processor; and

invoking the processor during execution of the continuous query, in response to receipt of structured data in said input stream to use the transform function to generate said output stream of structured data.

7. A computer-implemented method of processing streams of structured data using continuous queries in a data stream management system, the method comprising:

receiving a continuous query;

parsing the continuous query to identify an operator to extract a value from each tuple in an input stream of structured data and supply said value in a tuple in an output stream of scalar data;

inserting in a representation of the continuous query, a stream source representing said operator and having a value extraction function;

generating a plan, based on said representation, for execution of the continuous query including invocation of a processor; and

invoking the processor during execution of the continuous query, in response to receipt of said data in a stream of structured data, by using the value extraction function to supply said value on said output stream.