Scope

• The records resulting from searches may include duplicate records.
• This is particularly the case when you have:
  • Multiple sets resulting from alternative search strategies.
  • Simultaneous searching from two or more databases, such as using OneSearch categories or your own combinations of databases.

How to Elimate Duplicate Records

• Use identify duplicates (id) and remove duplicates (rd) operators.
• Combining sets of results using the not operator.

Using id and rd operators

Command	Operator	USAGE
identify duplicates	id	id s11 - Creates a set of records with all duplicate ones grouped together.
remove duplicates	rd	rd s3 - Removes duplicates in set 3 NOTE: Generally, you will just be using this operator, as this reduces the number of results that you may need to display.

NOTE: Only sets created by rd can be used in subsequent select (s) commands.

Using the not operator

• Example:
  • s cat? ? and leukemia
    • This results in Set 1 (s1)
  • s feline(w)leukemia
    • This results in Set 2 (s2)

  If s1 is larger than s2, then create the following combination search:

  • s s1 not s2
  • You winding up with a Set 3 (s3) that has all of the results in s1 minus the ones in s2 that duplicated those in s1.