The Join analysis is useful in joining together tables and/or views into an intermediate or final analytic data set. The Join analysis provides a graphical user interface to several of the most common, though certainly not all, join mechanisms in Teradata. Consequently, it should not be thought of or used as a complete replacement for SQL approaches to executing any generic Teradata join.
By default, an INNER join is performed on the given tables based on the given join columns. This means that rows will be returned only for join column values that appear in all selected tables. By option, a LEFT outer join can be requested, which returns rows for all join column values found in the first table, and substitutes NULL values for selected columns in the other tables that do not have rows with matching join column values. Alternatively, a RIGHT outer join can be requested to return all rows found in the last requested table, substituting NULL values for selected columns in the previous table for rows that do not have matching join column values (or in the cumulative right outer joins preceding it if more than two tables were selected). Finally, an option to perform a FULL outer join can be requested which retains all of the rows from all of the joined tables and, for each table, substitutes NULL values for selected columns in the other tables for rows that do not have matching join column values in those other tables.
The Join analysis is parameterized by specifying the table and column(s) to analyze, options unique to the Join analysis, as well as specifying the desired results and SQL or Expert Options.