[SOLVED] Do you use the OUTER keyword when writing left/right JOINs in SQL?

Do you use the OUTER keyword when writing left/right JOINs in SQL?

I often see people who write SQL like this:

SELECT * from TableA LEFT OUTER JOIN TableB ON (ID1=I2)

I myself write simply:

SELECT * from TableA LEFT JOIN TableB ON (ID1=I2)

To me the "OUTER" keyword is like line noise - it adds no additional information, just clutters the SQL. It's even optional in most RDBMS that I know. So... why do people still write it? Is it a habit? Portability? (Are your SQL's really portable anyway?) Something else that I'm not aware of?

Solution

OUTER really is superfluous, as you write, since all OUTER joins are either LEFT or RIGHT, and reciprocally all LEFT or RIGHT joins are OUTER. So syntactically it's mostly noise, as you put it. It is optional even in ISO SQL. As for why people use it, I suppose some feel the need the insist on the join being OUTER, even if the left-or-right keyword already says so. For that matter, INNER also is superfluous!