Horizontal Aggregations in SQL to Prepare Data Sets Using PIVOT Operator
R. Annamalai Saravanan, J. Sivapriya, M. Shahidha · 2013
Abstract--Preparing dataset is a very difficult process in cases where it has to be given as input for data mining which involves complex queries, joining tables, and aggregating columns. Existing SQL aggregations have limitations to prepare data sets because they return one column per aggregated group. Our project aims at implementing a new class of functions called horizontal aggregation. Horizontal aggregation build data set with a horizontal denormalized layout, which is the standard layout required by most data mining algorithms. PIVOT operator, offered by RDBMS is used to calculate aggregate operations. Our project aims at aggregating columns using PIVOT operator. Pivot operator is used to reorganize and summarize the selected columns and rows of data in a table to produce the desired reports. Using PIVOT operator horizontally aggregated data set is achieved which will act as input for any application involving data set. This horizontal aggregation will improve the performance of clustering process in data mining. Keywords--aggregation, dataset preparation, horizontal, pivoting, SQL. I.