Min/max query with synopsis guided scan order

• US 9,892,157 B2
• Filed: 12/07/2016
• Issued: 02/13/2018
• Est. Priority Date: 01/27/2016
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kalarikal Janardhana, Madhusudan, Patil, Andanagouda F., Pearson, Steven R.
• Primary Examiner(s): Perveen, Rehana
• Assistant Examiner(s): Tran, Loc
• Application Number:
  US15/371,609
• Publication Number:
  US 20170212936A1
• Time in Patent Office: 433 Days
• Field of Search: 707765, 707769, 707781
• CPC Class Codes: G06F 16/221 Column-oriented storage; Management thereof
• CPC Class Codes: G06F 16/2282 Tablespace storage structures; Management thereof
• CPC Class Codes: G06F 16/244 Grouping and aggregation
• CPC Class Codes: G06F 16/245 Query processing
• CPC Class Codes: G06F 16/24537 of operators
• CPC Class Codes: G06F 16/2455 Query execution
• CPC Class Codes: G06F 16/2457 with adaptation to user needs
• CPC Class Codes: G06F 16/248 Presentation of query results
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques
• CPC Class Codes: G06F 16/9535 Search customisation based on user profiles and personalisation
• CPC Class Codes: G06F 16/9538 Presentation of query results

Abstract

An approach for synopsis guided scan processing of MIN/MAX data queries where a minimal or maximal data query operation and a synopsis store are received. The synopsis store includes at least one of tuple range identifiers, column minimal and maximal metadata values. The synopsis store is sorted, where the column minimal or maximal metadata values search order is created for the tuple range identifiers. Dataset data associated with the tuple range identifiers is searched in the search order for a minimal or maximal value result until the minimal value result is less than or equal to a next column minimal metadata values or the maximal value result is greater than or equal to a next column maximal metadata values respectively and the minimal or maximal value result associated with the respective minimal or maximal data query operation is output.

Claims

1. A computer program product for synopsis guided scan processing of MIN/MAX dataset data value queries, the computer program product comprising:

one or more non-transitory computer readable storage media and program instructions stored on the one or more non-transitory computer readable storage media, the program instructions comprising;

program instructions to, receive, by MIN/MAX query executor, a minimal data query operation or a maximal data query operation to determine at least one of a minimal value result or a maximal value result, respectively;

program instructions to, receive, by the MIN/MAX query executor, a synopsis store wherein the synopsis store comprises one or more tuple range identifiers and at least one of one or more column minimal metadata values or one or more column maximal metadata values wherein each of the one or more tuple range identifiers is associated with a related dataset column;

program instructions to, sort, by the MIN/MAX query executor, the synopsis store, creating a search order of the one or more tuple range identifiers based on at least one of the one or more column minimal metadata values or the one or more column maximal metadata values, wherein the search order comprises sorting the one or more column minimal metadata values in ascending order and the one or more column maximal metadata values in descending order;

program instructions to, filter the search order, by the MIN/MAX query executor, creating an ordered filtered synopsis list comprising a predetermined quantity of the one or more tuple range identifiers wherein the predetermined quantity is based on at least one of a static value, calculated value, metadata statistics or dataset data statistics;

program instructions to, search, by the MIN/MAX query executor, dataset data values of the related dataset column associated with the one or more tuple range identifiers in the ordered filtered synopsis list for at least one of the minimal value result or the maximal value result until at least one of reaching an end of the ordered filtered synopsis list, the minimal value result is less than or equal to a next column minimal metadata value or the maximal value result is greater than or equal to a next column maximal metadata value respectively;

program instructions to, respond to reaching the end of the ordered filtered synopsis list, searching, by the MIN/MAX query executor, the dataset data values of the related dataset column further based on executing an unordered search wherein the unordered search searches a reduction of the synopsis store based on a subtraction of the one or more tuple range identifiers in the ordered filtered synopsis list from the synopsis store using a local predicate; and

program instructions to, output, by MIN/MAX query executor, at least one of the minimal value result or the maximal value result of the related dataset column associated with one of the minimal data query operation and the maximal data query operation respectively.