International Business Machines Corporation

Daniel Costante Zilio

Ting Yu Leung

Calisto Paul Zuzarte

David C Sharpe

Guy Maring Lohman

Adam J Storm

Sam Sampson Lightstone

Ian R Finlay

Bruce Gilbert Lindsay

Xin Wu

John Frederick Hornibrook

Qi Cheng

Gary Valentin

Paul C Huffman

Chi Man J Sizto

Kun Peng Ren

Kathy A McKnight

Steven M Chamberlin

Kevin H Low

Kevin Scott Beyer

David Everett Simmen

Roberta Jo Cochrane

Christian Marcelo Garcia-Arellano

Markos Zaharioudakis

Tony Wen Hsun Lai

Hamid Pirahesh

Matthew James Carroll

Adriana Zubiri

Kit Man Cheung

Samuel S Lightstone

Techniques are disclosed for generating statistical views in a database system. In one embodiment, a request is received to execute a database workload. One or more constraints pertaining to executing the database workload is retrieved. The database workload is evaluated to generate multiple statistical view candidates. The statistical view candidates are refined based on the one or more constraints. One or more statistical views are then generated based on the refined statistical view candidates.

Generating statistical views in a database system

Tuning a production database system through the use of a remote mimic. In response to receipt of a query tuning request against a database system, information about that system is obtained and a mimic of the system is set up in a remote system environment. The mimic aims to imitate the database system in all relevant ways with respect to the tuning request. A tuning analysis is then performed on this mimic system such that there is substantially no impact to operations of the original database system. Tuning results are then applied to the original database system. The entire process takes place with little or no human intervention.

Query tuning in the cloud

Methods and systems are provided for executing a simulation of an operation in a data processing system. In one implementation, the method includes executing an operation under a first set of conditions, determining a characteristic associated with the execution of the operation under the first set of conditions, and executing a simulation of the operation under a second set of conditions different from the first set of conditions. The simulation of the operation is constrained by the determined characteristic. The method can further include determining a cost/benefit of executing the operation under a set of conditions different from the first set of conditions based at least in part on the simulation.

Method and apparatus for simulating operation in a data processing system

A query processing system has a query processor and a data manager. The query processor calls the data manager to carry out data access for a query including a filtering operation. The data manager accesses the data in a set of data and before returning the data, initiates a callback to the query processor to determine if the located data meets the filtering criteria. Where the data does not satisfy the filtering criteria, the data manager seeks additional data in the set of data, without having to return the first located data to the query processor.

Execution of database queries including filtering

The retrieval of distinct tuples in a relational database management system. In response to a request from a consumer process for distinct tuples in a relational database table matching a defined criteria, a distinct operator component sequentially requests tuples from a source component. The source component access the database table and returns a tuple in the sequence to the distinct operator component. The distinct operator component passes each tuple in the sequence to an auxiliary logger. The auxiliary component receives a tuples from the distinct component and determines if it is distinct from other previously received tuples in the sequence to verify its uniqueness to the distinct operator. Tuples that are verified as unique by the auxiliary logger are returned to the consumer process by the distinct operator upon verification.

Method for unordered relational database retrieval returning distinct values

A query processing system having a data manager, and a query manager also includes a buffer. The query manager calls the data manager to access data based on a query. Where there is no predicate check or consumption operation on the record accessed, the data manager will notionally return the record to the query manager. However, the data manager accomplishes the return by writing the relevant portions of the record to a buffer. The data manager maintains stabilization of the page containing the record while the buffer is being written to. The data manager continues to access records on the stabilized page and to write such records to the buffer where appropriate. The query manager retrieves the records from the buffer after the data manager has completed its operation resulting from the query manager call.

Query execution in query processing systems

The invention herein provides method and apparatus, including software for determining a set of materialized views or indices of the contents or a subset of the contents of a database in a data processing system to be created for one or more users of the database. The method and apparatus provide method and means for evaluating a workload presented by a user to the database; evaluating the data processing system characteristics; evaluating the database characteristics; and, using the above evaluations for recommending a set of suitable materialized views or indices to the user. Another aspect of the invention, which may be used for a workload presented by a user of a database in a data processing system, provides method and apparatus, including software for determining a set of materialized views or indices of the contents or a subset of the contents of the database, by: generating a plurality of materialized view candidates from evaluation of the workload, data processing system characteristics and database characteristics; estimating statistics for the materialized view candidates such as the number of rows, row size, and column statistics; generating a plurality of potential index candidates by evaluating the workload, data processing system characteristics, database characteristics and the materialized view candidates; and, from the materialized view candidates and index candidates selecting a set of suitable materialized views and/or indices for submission to the user.

Method for recommending indexes and materialized views for a database workload

A system and method autonomically reallocate memory among buffer pools to permit quick access to data. A simulated buffer pool extension (SBPX) is created for each buffer pool in a set of buffer pools. Data victimized from a buffer pool is represented in the associated SBPX. Requests for data that is not resident in a buffer pool but is represented in the associated SBPX are tallied. Periodically, an expected efficiency benefit of increasing the capacity of each buffer pool is determined from the tallies. Memory is reallocated from the buffer pool with the lowest expected efficiency benefit having remaining reallocatable memory to the buffer pool with the highest expected efficiency benefit having remaining reallocatable memory, until either one or both of the buffer pools exhausts its reallocatable memory. This process is repeated until all reallocatable memory has been reallocated, until only one buffer pool with reallocatable memory remains, or until all buffer pools with remaining reallocatable memory have substantially the same expected efficiency benefit.

System and method for autonomically reallocating memory among buffer pools

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Georgetown, Canada

Daniel Costante Zilio