International Business Machines Corporation

Oliver Draese

Knut Stolze

Namik Hrle

Peter Bendel

Ruiping Li

Vijayshankar Raman

Tianchao Li

Oliver Benke

Oliver Koeth

Roland Seiffert

Michael M Skubowius

Andreas Brodt

Daniel Martin

Terence Patrick Purcell

Robert William Lyle

Thomas Abel Beavin

Guogen Zhang

Maryela Evelin Weihrauch

Julie Ann Watts

Torsten Steinbach

Andrei Fedorovich Lurie

Kalpana Shyam

Shuanglin Guo

Claus Kempfert

Brian L Baggett

Shengxi Suo

George F Wang

Shirley Zhou

Robert S Muse

Felix O Beier

James Alan Ruddy

Michael Jeffrey Winer

Jeremy B Jones

Benno Staebler

Robert Tokumaru

A method, system and computer program product are provided. A first index scan of records of a database table is performed. A first index used by the first index scan is specified in a DBMS query statement as being ordered by one or more field values of one or more fields of the first index. A second scan of the database table is performed to determine whether each respective record of the second scan is qualified based on one or more fields of the each respective record of the second scan and a predicate. A lookup data structure is built indicating whether each of the respective records of the second scan is qualified. The lookup data structure is used to determine whether a record of the first index scan is qualified when the lookup data structure becomes available.

Helper scan in a database management system

A system and method for creating a self-describing dictionary for expanding compressed data objects stored in a database of a database management system includes creating a dictionary associated with a data object that is customized to the data object, generating a custom expansion procedure for expanding the data object that is tailored to the dictionary, at a same time as creating the dictionary, and embedding the custom expansion procedure into the dictionary.

Dictionary embedded expansion procedure

A mechanism is provided for generating statistical information for query optimization in a data processing system. The mechanism comprises a first database engine maintaining a current first dataset currently being stored, a second database engine maintaining a second dataset. The second dataset is generated from previous first datasets or from the previous first datasets and current first dataset, the previous first datasets being datasets that were previously maintained by the first database engine. The first database engine receives a database query for accessing the first dataset, the database query involving one or more attributes of the first data set. The first database engine generates a query execution plan for the database query on the first dataset using collected statistical information on at least the second dataset. The first database engine processes the database query according to the query execution plan.

Query optimization in hybrid DBMS

A distributed database system (or federated database system) where a catalogue is used to store metadata descriptive of data containers for the constituent database system(s) and/or accelerator system(s) of the federated database. In response to the generation of the trigger signal corresponding to a database definition language (DDL) statement, the accelerator system updates metadata in the catalogue.

Distributed system with accelerator and catalog

In a high insert throughput in a database system, the database management system (DBMS) caches, asynchronously from data insert transactions, a list of storage location identifiers for storage locations in a table space in the database system. When a request for an insert transaction with an insert size is received from an agent, the DBMS identifies a storage location on the list with an amount of free space meeting the insert size. The DBMS removes the storage location identifier from the list and returns the storage location identifier for the storage location. When the insert transaction completes, the DBMS determines a remaining free space at the storage location and adds the storage location identifier to the list according to the remaining free space. By removing storage location identifiers from the list, another agent cannot receive the same storage location identifier for a parallel task. Thus, space contention is avoided.

Method and technique of achieving extraordinarily high insert throughput

Generating data structures for computer memory. Provisional data structures are generated that respectively have (i) a significand with an initial value of zero and (ii) an exponent that is included in a range of exponents. A test data structure from a provisional data structure by modifying a significand of the first provisional data structure using a significand of a floating-point number such that the significand of the first provisional data structure has a non-zero value. Modifying at least one provisional data structure based on a content of the test data structure. Generating a new data structure that represents the contents of a plurality of provisional-data structures. The plurality of provisional data structures includes at least one provisional data structure that was modified to include the significands of at least two floating-point numbers. The new data structure represents a value that is expressible by a limited number of memory bits.

Accuracy-conserving floating-point value aggregation

A distributed database system (or federated database system) where a catalog is used to store metadata descriptive of data containers for the constituent database system(s) and/or accelerator system(s) of the federated database. In response to the generation of the trigger signal corresponding to a database definition language (DDL) statement, the accelerator system updates metadata in the catalog.

A method for enhancing an accuracy of a sum of a plurality of floating-point numbers. The method receives a floating-point number and generates a plurality of provisional numbers with a value of zero. The method further generates a surjective map from the values of an exponent and a sign of a mantissa to the provisional numbers in the plurality of provisional numbers. The method further maps a value of the exponent and the sign of the mantissa to a first provisional number with the surjective map. The method further generates a test number from the first provisional number and if the test number exceeds a limit, modifies a second provisional number by using at least part of the test number. The method further equates the first provisional number to the test number if the test number does not exceed the limit. The method further sums the plurality of provisional numbers.

A distributed database system (or federated database system) comprises a constituent database management system (DMBS), an accelerator system and a single interface. The accelerator system creates a data container in accordance with structural features identified by the accelerator system and stores data in the data container. The constituent database system supplements incomplete metadata associated with the data container to create complete metadata descriptive of the namespace and structure of the data container created by the accelerator system.

Distributed system with accelerator-created containers

Methods for optimizing data access in a row-oriented relational database containing data sets having attributes using a computer are presented the method including: causing a computer to analyze a database workload to determine an access frequency for each of the attributes; causing the computer to assign each of the attributes to a priority classes corresponding with the access frequency, where the priority classes include a higher priority class and a lower priority class, and where a higher priority class corresponds with a higher access frequency and a lower priority class corresponds with a lower access frequency; causing the computer to store the attributes in accordance with the classes, where the attributes assigned to the higher priority class are stored in a high priority storage medium, and where the attributes assigned to a lower priority class are stored in a low priority storage medium.

Method and system for optimizing data access in a database using multi-class objects

A computer implemented method is provided for processing data representing a data entity having sub entities. The method includes analyzing queries to the data entity for deriving information about sets of the sub entities frequently queried together, and grouping the sub entities to a number of banks, each bank having a maximum width, based on the information about sets of sub entities frequently queried together, in order to reduce an average number of banks to be accessed for data retrieval.

Organization of data within a database

Growing community of inventors

Holzgerlingen, Germany

Oliver Draese