John Watson's blog

How to move a table from one schema to another

articles: 

Many times I've seen the question on forums "How can I move a table from one schema to another?" and the answer is always that you can't. You have to copy it. Or export/import it. Well, here's a way. It assumes that you are on release 12.x and have the partitioning option.

Oracle now supported on VMware

Oracle corporation will (as of 24 September 2019) support customers running on VMware.

19c Standard Edition permits 3 PDBs per CDB

articles: 

A very nice licensing change in 19c: you can now have up to three PDBs in a Standard Edition Multitenant database.

12.2 upgrade - it can break all your outgoing https calls

Do you know about multiple domain certificates? If not you may have to learn quickly, because Oracle has changed the way they are handled in release 12.2. This is going to break a lot of applications.

Upgrading to 12.2 ? Make sure you won't break JSON

articles: 

Will upgrade from 12.1 to 12.2 break your applications? It may if your developers are using JSON.

Tuning with equivalent SQLs - a little challenge

articles: 

I am fascinated by what I call "equal SQL": statements that are equivalent, in that they deliver the same result but may have hugely different performance characteristics. Here's a little case study.

Compression test, 12cR2

articles: 

Just how effective is Hybrid Columnar Compression? This test shows that HCC is impressive, but that thought needs to be put into choice of compression algorithm.

12cR2 lots of new instance parameters

articles: 

Comparing database 12cR1 release 12.1.0.2 to 12cR2 release 12.2.0.0.3, I see these new parameters:

12cR2 new feature: online table move

articles: 

Move a table without locks and without breaking indexes. That's pretty cool.

Is row-by-row processing really slow-by-slow? Emphatically: YES

articles: 

Developers who come to Oracle with a background in procedural languages sometimes do not understand how efficient SQL's set oriented processing can be. This little demonstration should convince them: never use PL/SQL when SQL will do.

Pages

Subscribe to RSS - John Watson's blog