Joining on substrings
Jonathan Lewis shared an example of joining two tables where the joining field on table is comprised of two fields on the other table. The original poster thought he’d need to re-design his table, but Jonathan proved otherwise with the grace and efficiency of a true Englishman.
Definitely good to know!
Back to Basics: Joins
Eddie Awad has an excellent series on the various join syntaxes, demonstrating both in the “old” Oracle syntax as well as the standard ANSI SQL92 syntax. Now you can get your head around inner vs outer joins and all the rest!
I’m going to make an effort to switch to the ANSI syntax for all the reasons that he lists.
IT’S THE JOIN[T]!
See what I did there? 5 points to anyone who can name the reference. 10 points if you can name the original reference that I wasn’t even thinking of. Void where prohibited.
Sachin, broadcasting live from his blog Oracle Online Help, has posted a nice primer on the differences between three join types that anyone who has ever look at a query plan will be familiar with: nested loops, hash joins, and sort-merge joins.
I definitely sleep a little better knowing what these mean. Now if only I knew what everything else meant.
