Database join with PDI
- PDI supports combination of two tables form the same database using a ‘Table Input’ method performing the join in SQL only.
- On the other side, for joining two tables in different databases, user implement ‘Database Join’ step.
- Though in database join, each input row query executes on the target system from the main stream, ensuing in lower performance as the number of queries implement on the B increases.
- To avoid the above issues, there is an another option to merge rows form two different Table Input steps.
- We can also use ‘Merge Join ‘step, using the SQL query having ‘ORDER BY’ clause. Remember, the rows must be perfectly sorted before implementing merge join.
