Forum Discussion
Left outer Join - but only selected columns from both tables
Hi - I feel this should be easy but I can't work it out. I have table A - it has let's say 50 columns, it's quite big. I have table B - let's say it also has 50 columns. I need to merge thes...
Performance of left outer join is not impacted by the number of columns.
BUT
In general, always start by selecting only the rows and the columns you need from every table you use.
Selecting the columns you need is easy:
- Select the columns by ctrl-click on the ones you need
- Right-Click on any of the selected columns and select "Remove other columns"
- The new step that is created has a little cogwheel!
- Click on the cogwheel if you change your mind and want to select more or fewer of the columns