What is the meaning of "*=" in TSQL syntax?

Question

I see the following syntax in a Sybase TSQL script I have to modify:

table1.Column1 *= table2.Column1

What does the *= portion of the syntax do?

Answer 1

That is the old way of writing a LEFT OUTER JOIN, =* is a RIGHT OUTER JOIN

These two are the same

New ANSI JOIN

SELECT * FROM Test2 t2
LEFT JOIN Test1 t1
ON t1.id = t2.id

Old JOIN

SELECT * FROM Test1 t1,Test2 t2
WHERE t1.id =* t2.id