Patent ID: 7454403
Filing Date: 2008-11-18
Classification: G06F,Y10S

Abstract:
1. A computer implemented method of improving performance of database query language statements for a database which comprises a data block, wherein the data block comprises a duplicated data value and a non-duplicated data value, the method comprising: identifying the duplicated data value in the data block and storing the duplicated data value in a first entry of a symbol structure for data duplication information; identifying the non-duplicated data value in the data block and not storing the non-duplicated data value in the symbol structure; calculating a number of occurrences of the duplicated data value in the data block; storing the number of occurrences of the duplicated data value in a second entry of the symbol structure for the data duplication information, wherein the identification of the duplicated data value and the calculation of the number of occurrences of the duplicated data value is determined before storing the duplicated data value in the symbol structure; receiving a database query language statement against data in the data block, the database query language statement comprising at least one predicate; and performing a number of predicate evaluations on data in the data block accessed by the database query language statement using the data duplication information stored in the symbol structure.