Database system and query optimiser

• US 20040093329A1
• Filed: 12/18/2003
• Published: 05/13/2004
• Est. Priority Date: 02/01/2001
• Status: Abandoned Application

• Current Assignee: SAP AG (SAP SE)
• Original Assignee: SAP AG (SAP SE)
• Inventors: Sauermann, Volker, Von Bergen, Axel, Schwarz, Arne
• Application Number:
  US10/470,716
• Publication Number:
  US 20040093329A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2246 Trees, e.g. B+trees
• CPC Class Codes: G06F 16/24545 Selectivity estimation or determination
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

Method for optimising a query with respect to a database structure. Database information is received with respect to a specific data source, a search database structure is generated for the data source, based on the received data source information, a query request is received for the data source, the search database structure is analyzed by counting a number of hits for respective sections of the query request, and an optimized query request is calculated based on the analysis performed.

Claims

1. Method for optimising a query with respect to a database structure, comprising:

receiving database information with respect to a specific data source (DS),

generating a search database structure (E) for said data source (DS), based on said received data source information,

receiving a query request for said data source (DS),

analyzing the search database structure (E) by counting a number of hits for respective sections of said query request, and

calculating an optimized query request based on the analysis performed.

2. Method according to claim 1, further comprising

generating said search database structure by organizing data elements of the same type in respective tree structures (A, B).

3. Method according to claim 2, further comprising

providing each data element of a tree with a number (COUNT) representative of the number of data elements arranged in the tree structure (A, B) under said respective data element.

4. Method according to any of the preceding claims, further comprising

linking elements of a first tree (A) with elements of a second tree (B) via linking elements (H), wherein a linking element represents a data record relation.

5. Method according to claim 4, further comprising

determining a key set for the optimized query request.

11. Computer program product, comprising code portions for executing when loaded into a computer memory the steps of a method according to any of the claims 1-5.

6. Database structure, for storage of data within a computer system, comprising

data elements of a first type (G), representing database entries, and

data elements of a second type (H), associated with said data elements of the first type (G),

wherein the data elements of the first type (G) are arranged in a first tree structure, and

wherein the data elements of the second type (H) are arranged in a second tree structure.

7. Data structure according to claim 6, wherein end sections of the tree structures are connected via linking elements to a start section of the tree structure.

8. Data structure according to claim 6 or 7, wherein multiple occurrences of similar data elements of the first type (G) are arranged in a set of data elements that are mutually connected through linking elements, and wherein one data element of the set is directly part of the respective tree structure.

9. Data element for a database structure according to any of the preceding claims 6-8, comprising

a first pointer pair (LSR, RSR),

a second pointer pair (LHR, RHR),

a third pointer pair (LVR, RVR).

10. Data element according to claim 9, further comprising an IF pointer (IF).