From my own practice: I always use table aliases when two or more tables will be JOINed (and never use an alias if no JOIN is involved). Advantages:

- I always understood that the SQL engine will be faster, if field names will be fully qualified (when working within a single database: having schema plus tablename prefices): the engine does not have to find out which schema/table contains the specified field.

- Readability: I certainly prefer to read tens of "TT."-s above tens of "dbo.tblTrabeculectomyTechniques."-s. When I see my SQL code after a few years, I feel comfortable (and I assume my collegues will feel comfortable as well).

Another suggestion: I always use a syntax like: "dbo.tblTrabeculectomyTechniques As TT", instead of "dbo.tblTrabeculectomyTechniques TT". I find this much easier to read.

Leendert.