It’s Private

“The only thing you can do easily is be wrong, and that's hardly worth the effort.” 
― Norton Juster, The Phantom Tollbooth

Oracle provides two parameters that affect the PGA that look very similar but operate very differently. One of these parameters is the well-known pga_max_size and the otheris a hidden parameter, _pga_max_size. Let’s look at both and see how one can be very effective while the other can create problems with respect to (more...)

Return To Sender

"The most important reason for going from one place to another is to see what's in between."
-- Norton Juster, The Phantom Tollbooth

Recently in an Oracle forum a question resurfaced regarding enabling row movement for tables. The posted question, from five years ago, asked if row movement was safe and if there could be any ‘undesired impact on application data’. The answer to the first part of that question is ‘yes’ (it’s safe (more...)

“Back It Up!!!”

“Expectations is the place you must always go to before you get to where you're going.” 
― Norton Juster, The Phantom Tollbooth   

In a recent post in the Oracle General database forum the following question was asked:


I have 3 schema's of almost equal sizes, off which only two are creating the backup's (Hot backup). One of the schema's is not creating any backup, by not creating I mean, the backup file that  (more...)

“Do You Have A Key?”

“Don't you know anything at all about numbers?"
"Well, I don't think they're very important," snapped Milo, too embarrassed to admit the truth.
"NOT IMPORTANT!" roared the Dodecahedron, turning red with fury. "Could you have tea for two without the two — or three blind mice 
without the three? Would there be four corners of the earth if there weren't a four? And how would you sail the seven seas without a seven? (more...)

Taking Things For Granted

"Sometimes I find the best way of getting from one place to another is simply to erase everything and begin again."
-- Norton Juster, The Phantom Tollbooth

In one of the Oracle forums a question was asked regarding revoking selected privileges from the DBA role. Unfortunately for the person posting the question the answer is a resounding “No”; granting a role grants all privileges assigned to that role and there is no “picking and (more...)

“That STILL Ain’t Right”

"If you want sense, you'll have to make it yourself."
- Norton Juster, The Phantom Tollbooth

In a recent post to an Oracle forum a query was presented and a tuning request was made. It appears that the query was taking 20 hours to complete. Through further interrogation and responses it was discovered that the dates were being stored in a VARCHAR2 column and implicit date conversion was being used. To show how much (more...)

“That’s Not What I Wanted.”

"Let me try once more," Milo said in an effort to explain. "In other words--"
"You mean you have other words?" cried the bird happily. "Well, by all means, 
use them. You're certainly not doing very well with the ones you have now."
-- Norton Juster, The Phantom Tollbooth

A recent question in the Oracle database forums has a user wanting to open his physical standby database in READ WRITE mode but still (more...)

“If You Change This, Right Here …”

"changes are so frightening."
-- Norton Juster, The Phantom Tollbooth

It isn’t unusual for Oracle to expand functionality with each new release; a short list includes AWR, ADDM, the SYSAUX tablespace, Flashback Query, Flashback Database and Edition-based Redefinition. Oracle 12.1 is no different as it provides an interesting performance enhancement, the in-memory column store, that can increase performance by reducing physical I/O load by making tables memory-resident (to simplify the description somewhat). Inn (more...)

It’s A Match

"So many things are possible as long as you don't know they're impossible."
-- Norton Juster, The Phantom Tollbooth

With every new release Oracle provides new features that are very useful, even if you didn’t think of them before. In Oracle provides a new functionality for finding pattern matches in a data set; using the MATCH_RECOGNIZE function it’s fairly easy to generate results based on a defined pattern in the (more...)

“I Appreciate You”

Today, October 11, 2016, is OTN Appreciation Day. In honor of that I wanted to post my favorite offering from Oracle — Exadata. Yes, I’m biased but even at that the Exadata platform is an outstanding offering from Oracle. Let’s look at some of the ways Exadata provides performance and value.

Exadata is an engineered system, meaning that all of the components are selected and configured to work together to provide performance. Part of that (more...)