The Execution Result tab in the SQL Optimizer window compares the data returned by the original SQL with the data returned by any one of the SQL alternatives.
To compare all rows of data between the original SQL and an SQL alternative
To compare a limited number of rows between the original SQL and an alternative
The grid in the top pane provides quick overview of returned-data differences. The numbers of returned columns and rows show whether the SQL alternative produces the same result as the original SQL statement. The displayed time shows how long it took to execute Batch Run or the Run Time, not the time it took to retrieve the data for the Execution Result tab.
Note: If the Data statistic shows that the returned data differs when you retrieve limited rows, do not assume that the alternative is returning wrong data. The difference can suggest that the alternative has returned data in an order different from the order returned by the original SQL. Two SQL statement are considered to be semantically equivalent if they retrieve the same data in any order (as long as the ORDER BY clause is not used in the SQL statement).
To refresh the data for the currently selected alternative
To clear all the data for original and all alternatives
To abort Compare SQL or Refresh SQL process