Oracle 10g: Top Goodies and Gotchas by Mike Ault

AMM (Automatic Memory management). "Because DBAs spend a large amount of time monitoring and tuning the SGA areas in Oracle, AMM relieves them of a majority of this chore," Ault said.

Automated diagnostics through ADDM ("Adam"). "This process collects the needed statistics, SQL statements and other required data to analyze performance bottlenecks and provide detailed recommendations to the DBA," he said. "In addition, ADDM can be used to do detailed analysis of SQL statements to develop a SQL profile that can be used to tune previously 'un-tunable' SQL such as third-party application SQL."

ASM (Automated Storage management). "This allows the DBA to set and forget datafile, redo log and other file areas," Ault said. "ASM provides for automated striping and mirroring as well as backup of Oracle-related files. ASM replaces more expensive disk management software (as related to Oracle data files)."

Enterprise manager and Grid Control. "There are so many enhancements in EM that it is difficult to pinpoint one that really shines," Ault said. "However, the automation of backups via a simple point-and-click interface has to be right up there. In addition, the fully Web-compliant interface that allows a DBA to manage [his or her] environment from anywhere they have access to the Internet is also a great convenience.

Improvements to the wait interface. This eliminates the need to dig for child wait information and the grouping of related waits by category, Ault said.

Fair enough—those are the time-savers to which we can look forward. But what about the top gotchas? What should DBAs look out for when working in 10g? Here's that list:

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• Automated features don't quite replace an experienced DBA. Rather than blindly following all ADDM suggestions, for example, DBAs must monitor the AMM to make sure it's not overallocating memory areas, Ault suggests. Use ADDM suggestions as guidelines for tuning, based on your own knowledge of the database being tuned.

• Verify all backups by performing recoveries.

• The EM interfaces are nice, but knowing the underlying data dictionary is still critical.

• Start the ASM instance first and shut it down last. "ASM controls access to the disks," Ault says, "and if the ASM instance is not started, none of the other databases can mount their data files. If the ASM instance shuts down, all of the other dependent databases will crash. Another thing to watch out for in ASM is that, at least for now, you must use the EM interface and RMAN to back up a database that uses ASM."

• Watch out for everything you always watched out for. That includes ensuring that you have enough disk space, watching the placement of ASM RAW devices for file I/O balancing (replacing watching the placement of data files), and making sure that all appropriate OS and Oracle patches are applied.

Finally, I wanted to know what the top things are that Oracle still needs to iron out. In Ault's view, one shortcoming has to do with the fact that the current streams interface is still in the Java version of the enterprise manager. That means you need to have two sets of EM software if you want to use streams features. That also applies to other features, Ault told me.

In addition, some of the EM screens could be more intuitive to navigate. Ault would also be pleased by seeing more tabular results, with reports backing up what's now just nice graphics. As far as RAC (Real Application Clusters) goes, "some of the install is still rather rough," Ault opined, so more work on that would be welcome.