Just released an article on Table Compression Enhancements in 11g.
Cheers
Tim…
Iron Man…
Iron Man is the best superhero film I’ve seen in ages. It’s got some iconic scenes, some funny bits and some real actors. I can’t wait for the sequel (or is that SQL?). 🙂
Cheers
Tim…
Multiplexed redo logs and archiving by default?
After yet another post by someone whose database has crashed without running in archivelog mode and without having multiplexed redo logs, it makes me think it’s about time Oracle changed the default installation to include both these things.
Over the last few versions, Oracle have consistently made the database easier to install and use, but they still leave these gaping holes. Yes, archivelog mode is set if you choose to setup backups during the installation, but there’s nothing to stop you defaulting this setting even when backups are not initiated during the installation.
I realise some people will react by saying it’s up to the DBA to make this decision, but there are obviously lots of people out there that either don’t understand the issue, or don’t even know about it. It would seem sensible to me that Oracle install the product in the safest mode possible. Afterall, it’s no problem backing them out if you don’t need them.
I for one would rather have people complaining about disks filled with archived redo logs, than having unrecoverable databases.
Rant over. 🙂
Cheers
Tim…
SQL Sharing Criteria…
I’m a big fan of the Oracle documentation, but sometimes things go astray. A recent question by Aman Sharm about SQL sharing critera highlighted this…
In the 8iR3 manual, the decision process for finding matching SQL is listed as:
- The text string of an issued statement is hashed. If the hash value is the same as a hash value for an existing SQL statement in the shared pool, then Oracle proceeds to Step 2.
- The text string of the issued statement, including case, blanks, and comments, is compared to all existing SQL statements that were identified in Step 1.
In the 9iR1 manual it was rewritten to include all the steps for identifying the match in a single bullet point:
- The text of the statement issued is compared to existing statements in the shared pool.
The text of the statement is hashed. If there is no matching hash value, then the SQL statement does not currently exist in the shared pool, and a hard parse is performed.
If there is a matching hash value for an existing SQL statement in the shared pool, then Oracle compares the text of the matched statement to the text of the statement hashed to see if they are identical.
So the first line is like a summary of the whole bullet point, which is then expanded.
In the 9iR2 manual, this was reverted back to individual bullet points, but the author/editor must have assumed the initial summary line was a separate point, so a new step was introduced into the documentation of the process:
- The text of the statement issued is compared to existing statements in the shared pool.
- The text of the statement is hashed. If there is no matching hash value, then the SQL statement does not currently exist in the shared pool, and a hard parse is performed.
- If there is a matching hash value for an existing SQL statement in the shared pool, then Oracle compares the text of the matched statement to the text of the statement hashed to see if they are identical.
And this is the way it stayed from 9iR2 to 11gR1. 🙁
I’ve raised a bug against the documentation, so it should get corrected now. 🙂
Cheers
Tim…
WordPress 2.5.1…
If you are reading this it means my blog has been upgraded to the latest release of WordPress (2.5.1). 🙂
Cheers
Tim…
Sky Blue (Wonderful Days)…
I was standing in HMV the other day, trying to convince myself not to buy a Nintendo WII with WII Fit and SuperMario Kart, when I noticed the film Sky Blue was being sold for £5. I’d been toying with the idea of buying this for some time, but a reduction of $15 pounds forced my hand. 🙂
Like many of the Japanese Anime, this Korean Anime is set in a post apocalyptic (pollution not war) future. You can read more about the story here.
It’s like a grittier version of AppleSeed, with equally good visuals. If you like the genre, give it a try…
Cheers
Tim…
Street Kings…
I went to see Street Kings at the weekend. In summary, good cops, bad cops and cops that don’t know if they are good or bad.
Keanu Reeves is OK. Forest Whitaker if very over the top, with a few scenes of frantic head wobbling. Not sure what to make of him.
It was OK, but it didn’t exactly change my life. There’s nothing in the film that warrants a big screen viewing, so you might be just as well waiting for the DVD rental.
Cheers
Tim…
SecureFiles in Oracle 11g…
I’ve just posted an article on SecureFiles in Oracle 11g. It looks like Oracle have done a pretty good job of improving LOBs in 11g. Depending on the LOB contents, and provided you can cope with the processing overhead, you can certainly save some serious space using the compression and deduplication options. Anyone who’s used Transparent Data Encryption (TDE) will recognize the encryption options.
I can’t see the old-style (BasicFile) LOBs lasting very long now this is in place. 🙂
Cheers
Tim…
Lords and Ladies and Men at Arms…
My quest to read the Discworld series continues:
Lords and Ladies – This book starts where Witches Abroad finished. This time the witches have to prevent elves returning to the Discworld. Love, marriage, death and elves. What more could you want. 🙂
Men at Arms – I keep reading these books and saying, “This one is my favorite!”, only to read the next and have it become my new favorite, but Mean at Arms is a classic!
Cheers
Tim…
Tablespace Encryption in 11g…
I spent yesterday looking at the Tablespace Encryption feature in Oracle 11g. If you’ve used the Transparent Data Encryption (TDE) feature in 10g release 2, you’ll see this is more of the same. The difference here is eveything in the tablespace is encrypted, rather than having to decide on a column-by-column basis. Just create the appropriate tablespace and Bob’s your uncle!
You may notice the article conveniently side-steps the Hardware Security Modules related functionality. I don’t have one so I can’t test it out. 🙂
For most of the stuff I work on, encrypting all the columns in a table is overkill, but I guess there are some areas where this is a big priority. It’s good to know it’s there in case you ever need it. 🙂
Cheers
Tim…