International Business Machines Corporation

Robert Douglas Driesch, Jr

Paul Reuben Day

Jeffrey Wayne Tenner

Randy Lynn Egan

Robert J Bestgen

Shantan Kethireddy

Ulrich Thiemann

Andrew Peter Passe

Wei Hu

John David Dietel

Robert Victor Downer

Mi Huynh

Edward J Miller

Brian Robert Muras

Mark John Anderson

Michael Steven Faunce

Lance Christopher Amundsen

Abdo Esmail Abdo

Thomas James Schreiber

John Francis Edwards

Daniel Virgil Toft

Techniques for replication rule evaluation are provided. A replication rule is received at a first node of a plurality of nodes where the replication rule defines object replication among the plurality of nodes. The replication rule is labeled as pending, where a second replication rule on the first node is labeled as active. Upon receiving a request to predict an effect of the replication rule, a first object of a plurality of objects is identified based on the first replication rule. Upon determining that the first object is present on the first node but is not present on a second node of the plurality of nodes, an indication of the first object is outputted.

Evaluating pending object replication rules

Techniques for dynamically detecting objects that are out of sync in an active mirrored environment are provided. A request is received at a local node of an active mirroring environment from a system function to perform a change operation on an object. Upon determining that the object is OOS, it is determined whether the local node or a remote node of the active mirroring environment has the most recent changes for the object. In one embodiment, the determination includes analyzing corresponding time stamps of changes listed in a repository of changes for objects in the mirrored environment. Upon determining that a remote node has the most recent changes for the object, a blocking attribute is set and the requested operation on the object blocked. However, upon determining that the local node has the most recent changes for the object, a tracking attribute is set and the requested operation allowed.

Method to dynamically detect objects out of sync in an active mirroring environment

Methods, systems, and products are provided for code path tracking. Embodiments include identifying an instrumented trace point in software code to be path tracked; identifying a function executed at the instrumented trace point in the software code; identifying parameters for the function executed at the instrumented trace point; and recording a description of the function, the parameters, and the result of the execution of the function using the parameters.

Code path tracking

A method generates at least one statistic for a temporary table during optimization of a database query before the temporary table is created. By doing so, optimization can proceed on a database query irrespective of the fact that the temporary table may not be materialized until the database query is ultimately executed.

Generating statistics for temporary tables during query optimization

A database query optimizer for a computer system having dynamically configurable logical partitions generates an optimized query strategy which is dependent on a logical partition configuration. When the query is executed, the configuration of the logical partition in which the query is executed is compared to the logical partition configuration for which the query was optimized. If the configurations are different, a new query can be automatically generated. Optimizing database queries to the current system configuration of a dynamic, logically partitioned system potentially offers greater efficiency in the execution of database queries for complex, logically partitioned systems.

Method and apparatus for optimizing queries in a logically partitioned computer system

Methods, systems and articles of manufacture for selectively maintaining query implementation information. A user is able to set a Predictive Query Threshold which will be honored by a database system to determine for which queries information will be collected. In one embodiment, the decision about whether to collect information for a query is made before the query starts to run (i.e., before the plan is executed) by comparing the Predictive Query Threshold to some cost factor (e.g. estimated runtime). In another embodiment, each query may be monitored but the query implementation information is only selectively logged. Specifically, the determination as to whether query implementation information for a query should be logged is made after the query implementation information is collected.

Reduce database monitor workload by employing predictive query threshold

Query results and statistics regarding them are generated using a novel representation of an n-attribute relation as an order n relational tensor. Orders of the relational tensor respectively correspond to each of the attributes, and each coordinate along an order relates to a key value of the corresponding attribute. Numeric values are stored in the relational tensor, each numeric value representing a count of tuples having the attribute key values that correspond to the coordinate of the numeric value along the orders of the relational tensor. This storage representation is useful in a variety of contexts for enhancing the performance of a RDBMS system. Specifically, a data-representing relational tensor can be used to produce results for join operations such as the SQL operations JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN and FULL OUTER JOIN.

Generating join queries using tensor representations

A method and computer program product are provided for processing system files. An associated trigger program is attached to each respective system file. The associated trigger program is utilized for pre-processing the respective system file to identify predetermined information. The identified predetermined information is stored in an internal structure. The internal structure is utilized to access the predetermined information when required to perform a query.

Growing community of inventors

Rochester, MN, United States of America

Robert Douglas Driesch, Jr