摘要:
Techniques for detecting patterns in one or more data or event streams. A pattern to be detected may be specified using a regular expression. Events received in a data stream are processed during runtime to detect occurrences of the specified pattern in the data stream. In one embodiment, a pattern type or class is determined for the specified pattern and pattern matching is performed using a technique selected based upon the type or class determined for the specified pattern.
摘要:
A method system and program for performing a query in which context and information including opcodes accompanies an execution plan for the query. The opcodes determine operations to retrieve a set of bind variables. The execution plan and context information shared by a plurality of application programs.
摘要:
Techniques for facilitating communication between one or more client applications and an event processing server. In one set of embodiments, a framework is provided that enables a client application to communicate with an event processing server via a standard database connectivity API, such as Java Database Connectivity (JDBC).
摘要:
Facilitating flexible windows in querying continuous data streams. In one embodiment, a software code is associated with a window, wherein execution of the software code determines the values to be included in the window. On receiving a query indicating the window, the result of the query is generated based on the values in the window determined by execution of the software code. The software code may be identified by an identifier and thus used for different queries on the same or different continuous data streams.
摘要:
A system and method for enabling a second database instance to more quickly process a request to execute a database statement that has previously been executed by a first database instance is described. In one embodiment, the method involves sending the database statement from the first database instance to the second database instance, and generating by the second database instance one or more structures needed to prepare the statement for execution, such as a parse tree and an execution plan for the statement. If at some point in the future, the second database instance receives a request to execute the same statement, the above structures can be used for execution, thereby eliminating the need for one or more potentially time-consuming operations, such as generation of a parse tree or execution plan for the statement.
摘要:
A method and apparatus for loading an XML document into memory is provided. A client loads one or more array elements into a first partition of an array that is maintained in memory. Each array element represents an XML element of an XML document. Upon determining that an amount of data maintained in the first partition exceeds a first threshold, the client subsequently loads array elements into a new partition of the array. Upon determining that an amount of data maintained in the memory of the client exceeds a second threshold, the array elements of the least recently used partition are persistently stored in a database without persistently storing the entire XML document. When the last XML element of the XML document is loaded into a partition of the array, that partition is persistently stored in the database, thereby causing the entire XML document to be stored in the database.
摘要:
A method and apparatus for reverting a resource to a prior state in time is provided. Changes are committed to a resource at a particular point in time. After the particular point in time, a request, which may be a file system operation request, to revert the resource to a state prior to the particular point in time is received at a database server. In response to the request, the resource is reverted to the state prior to the particular point in time. The current state of the resource ceases to reflect the plurality of changes. Advantageously, if a requestor creates an incorrect version of a resource, the changes made to a schema-based resource are not compatible with the schema, or the changes of multiple requesters are not compatible with each other, the resource may be reverted to the earlier point in time.
摘要:
Techniques for detecting patterns in one or more data or event streams. A pattern to be detected may be specified using a regular expression. Events received in a data stream are processed during runtime to detect occurrences of the specified pattern in the data stream. In one embodiment, a pattern type or class is determined for the specified pattern and pattern matching is performed using a technique selected based upon the type or class determined for the specified pattern.
摘要:
Techniques for detecting patterns in data streams. A pattern to be detected may be specified using a regular expression. Events received in data streams are then processed during runtime to detect occurrences of the pattern specified by the regular expression in the data stream. If the pattern to be matched belongs to a certain predetermined class of patterns, then a pattern matching technique that is customized for that class of patterns is used during the runtime events processing.
摘要:
A computer is programmed to accept a command to create a new aggregation defined by a user during execution of continuous queries on streams of data. The computer is further programmed to thereafter accept and process new continuous queries using the new aggregation, in a manner similar to built-in aggregations. The user typically writes a set of instructions to perform the new aggregation, and identifies in the command, a location of the set of instructions. In response to such a command, the computer creates metadata identifying the new aggregation. The metadata is used to instantiate one aggregation for each group of data in a current window, grouped by an attribute identified in a new query.