Sometimes in the IT world, the term “surprise” is not a good one.

“I woke up this morning and got a …my database was down.”

“I ran a SELECT COUNT(*) on my most important table, and got a result of zero rows.”

and so forth. Generally as IT professionals, encountering the unexpected is not a good start to the day .

But sometimes, surprises can be a nice thing.  Here is my example for today – when I found that the database can do a remarkably good job when it comes to reducing the workload with partitioned tables.  

Most people will already be familiar with the concept of partition elimination.  If you have a table partitioned into (say) yearly segments, and you ask for all of the data for the past 2 years, then the optimizer is intelligent enough to only scan the relevant partitions rather than the entire…