Patents by Inventor Kostas Rakopoulos

Kostas Rakopoulos has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11847121
    Abstract: Methods, computer program products, and systems are presented. The method computer program products, and systems can include, for instance: obtaining a query statement; parsing the query statement and determining from the parsing that the query statement is a compound predicate query statement that includes a first predicate and a second predicate; responsively to the parsing, rewriting the obtained query statement to provide a transformed query statement, wherein the rewriting includes (a) specifying generating of a temporary table, wherein the specified generating uses data values of the first predicate and (b) specifying a join function that uses the temporary table and a table referenced in the query statement; evaluating a candidate access path associated to the transformed query statement; selecting the candidate access path as an access path for execution; and executing the transformed query statement according to the selected candidate access path for execution.
    Type: Grant
    Filed: August 27, 2021
    Date of Patent: December 19, 2023
    Assignee: International Business Machines Corporation
    Inventors: Daniele Costante Zilio, Muhammad Esaad Afaque, Darren Andrew Pepper, Xi Sun, Kostas Rakopoulos
  • Publication number: 20230082446
    Abstract: Methods, computer program products, and systems are presented. The method computer program products, and systems can include, for instance: obtaining a query statement; parsing the query statement and determining from the parsing that the query statement is a compound predicate query statement that includes a first predicate and a second predicate; responsively to the parsing, rewriting the obtained query statement to provide a transformed query statement, wherein the rewriting includes (a) specifying generating of a temporary table, wherein the specified generating uses data values of the first predicate and (b) specifying a join function that uses the temporary table and a table referenced in the query statement; evaluating a candidate access path associated to the transformed query statement; selecting the candidate access path as an access path for execution; and executing the transformed query statement according to the selected candidate access path for execution.
    Type: Application
    Filed: August 27, 2021
    Publication date: March 16, 2023
    Inventors: Daniele Costante ZILIO, Muhammad Esaad AFAQUE, Darren Andrew PEPPER, Xi SUN, Kostas RAKOPOULOS
  • Patent number: 10970173
    Abstract: A logging process in a data storage system having a set of storage tiers, each storage tier of the set of storage tiers having different performance characteristics, wherein the set of storage tiers is divided into a plurality of subsets of storage tiers using the performance characteristics, may include initiating the logging process for creating a separate log file for each of the plurality of subsets of storage tiers for maintaining a history of data changes in the subset of storage tiers, thereby creating a plurality of log files. In response to a change in data stored in at least one storage tier of a subset of storage tiers of the plurality of subsets of storage tiers, one or more log records including information about the change may be generated and written into respective log files.
    Type: Grant
    Filed: November 30, 2018
    Date of Patent: April 6, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Martin Oberhofer, Jens P. Seifert, Kostas Rakopoulos, Stephen Rees
  • Publication number: 20190102259
    Abstract: A logging process in a data storage system having a set of storage tiers, each storage tier of the set of storage tiers having different performance characteristics, wherein the set of storage tiers is divided into a plurality of subsets of storage tiers using the performance characteristics, may include initiating the logging process for creating a separate log file for each of the plurality of subsets of storage tiers for maintaining a history of data changes in the subset of storage tiers, thereby creating a plurality of log files. In response to a change in data stored in at least one storage tier of a subset of storage tiers of the plurality of subsets of storage tiers, one or more log records including information about the change may be generated and written into respective log files.
    Type: Application
    Filed: November 30, 2018
    Publication date: April 4, 2019
    Inventors: Martin Oberhofer, Jens P. Seifert, Kostas Rakopoulos, Stephen Rees
  • Patent number: 10176049
    Abstract: A logging process in a data storage system having a set of storage tiers, each storage tier of the set of storage tiers having different performance characteristics, wherein the set of storage tiers is divided into a plurality of subsets of storage tiers using the performance characteristics, may include initiating the logging process for creating a separate log file for each of the plurality of subsets of storage tiers for maintaining a history of data changes in the subset of storage tiers, thereby creating a plurality of log files. In response to a change in data stored in at least one storage tier of a subset of storage tiers of the plurality of subsets of storage tiers, one or more log records including information about the change may be generated and written into respective log files.
    Type: Grant
    Filed: July 7, 2014
    Date of Patent: January 8, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Martin Oberhofer, Jens P. Seifert, Kostas Rakopoulos, Stephen Rees
  • Publication number: 20160162366
    Abstract: A logging process in a data storage system having a set of storage tiers, each storage tier of the set of storage tiers having different performance characteristics, wherein the set of storage tiers is divided into a plurality of subsets of storage tiers using the performance characteristics, may include initiating the logging process for creating a separate log file for each of the plurality of subsets of storage tiers for maintaining a history of data changes in the subset of storage tiers, thereby creating a plurality of log files. In response to a change in data stored in at least one storage tier of a subset of storage tiers of the plurality of subsets of storage tiers, one or more log records including information about the change may be generated and written into respective log files.
    Type: Application
    Filed: July 7, 2014
    Publication date: June 9, 2016
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Martin Oberhofer, Jens P. Seifert, Kostas Rakopoulos, Stephen Rees