Mastering Duplicates Removal in SAS: A Comprehensive Guide to Using PROC SQL, DATA STEP, and PROC SORT
Removing Duplicate Observations in SAS: A Comprehensive Guide Removing Duplicate Observations in SAS: A Comprehensive Guide In data analysis, it's common to encounter datasets with duplicate records that need to be cleaned up. SAS offers several methods to remove these duplicates, each with its strengths and suitable scenarios. This article explores three primary methods for removing duplicate observations: using PROC SQL , the DATA STEP , and PROC SORT . We will provide detailed examples and discuss when to use each method. Understanding Duplicate Observations Before diving into the methods, let's clarify what we mean by duplicate observations. Duplicates can occur in different forms: Exact Duplicates: All variables across two or more observations have identical values. Key-Based Duplicates: Observations are considered duplicates based on the values of specific key variables (e.g., ID, Date). The ...