Tag: partitioning

Cool stuff with partition elimination

Sometimes in the IT world, the term “surprise” is not a good one. “I woke up this morning and got a surprise…my database was down.” “I ran a SELECT COUNT(*) on my most important table, and got a surprise result of zero rows.” and…

18c merge partition online

One of the cool things in 18c is the ability to merge partitions without causing a service interruption.  Here’s a video demonstration of that in action: This is just an accompanying blog post to let you grab the scripts for the demo so that…

iASH–my “infinite ASH” routine

I love Active Session History (ASH) data because a lot of the work I’ve done in my consulting life was “after the fact” diagnosis.  By this I mean that many of us have been in a similar circumstance where the customer will contact you…

Partition-wise join

So just what is a “partition-wise” join ?  We will use a metaphor to hopefully explain the benefit. Let’s say two people, Logan and Shannon, decide to move in together.  If each of them already have an existing residence, they will both have a…

Updating indexes with partition maintenance

An index is basically a structure that maps keys (values) in columns to the physical location of their corresponding rows in a table.  So if you move the rows (ie, change the physical location of a row) then the index entries for those rows…

Partitioning Guide updated

Just a quick note to say I’ve updated our Getting Started With Partitioning Guide! 9 easy to follow demonstrations to get developers up to speed with handling large databases. Check it out here

12c Statistics on load–special cases

One of the cool features in 12c is the automatic collection of optimizer statistics when a table is either created or loaded via direct path from empty.  This makes a lot of sense because it saves us from what used to be the mandatory…