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June 2008

More Mass Market Oracle

Almost exactly one year ago, I wrote about the lack of hosted Oracle database packages.  Since then I haven’t seen much movement on that front, until last week, when STRATO AG, a German hosting company started offering a STRATO Oracle Server hosting package based on Parallels Virtuozzo Containers and Oracle Express Edition.  Here’s the press release.  I’m having a bit of trouble finding the package on the STRATO site, but if it’s true it’s another valuable option out there for ways to increase Oracle usage at the low end (where a lot of innovation takes place).  I’m curious how STRATO is handling the Oracle licensing issues…

cursor_space_for_time To Be Deprecated

If you haven’t seen the Meatlink note 565424.1 in the news yet, cursor_space_for_time parameter will be deprecated in Oracle 10.2.0.5 and 11.1.0.7.
That’s kind of good news, I hope this will eventually reduce the number of expert DBAs who set this parameter to true whenever they see any kind of shared pool / library cache latch contention.
On the other hand, spin_count was made an undocumented parameter long time ago, but is still heavily abused worldwide so I wouldn’t be surprised if the same happens to future _cursor_space_for_time…

cursor_space_for_time To Be Deprecated

If you haven’t seen the Meatlink note 565424.1 in the news yet, cursor_space_for_time parameter will be deprecated in Oracle 10.2.0.5 and 11.1.0.7.
That’s kind of good news, I hope this will eventually reduce the number of expert DBAs who set this parameter to true whenever they see any kind of shared pool / library cache latch contention.
On the other hand, spin_count was made an undocumented parameter long time ago, but is still heavily abused worldwide so I wouldn’t be surprised if the same happens to future _cursor_space_for_time…

cursor_space_for_time To Be Deprecated

If you haven’t seen the Meatlink note 565424.1 in the news yet, cursor_space_for_time parameter will be deprecated in Oracle 10.2.0.5 and 11.1.0.7.
That’s kind of good news, I hope this will eventually reduce the number of expert DBAs who set this parameter to true whenever they see any kind of shared pool / library cache latch contention.
On the other hand, spin_count was made an undocumented parameter long time ago, but is still heavily abused worldwide so I wouldn’t be surprised if the same happens to future _cursor_space_for_time…

cursor_space_for_time To Be Deprecated

If you haven’t seen the Meatlink note 565424.1 in the news yet, cursor_space_for_time parameter will be deprecated in Oracle 10.2.0.5 and 11.1.0.7.
That’s kind of good news, I hope this will eventually reduce the number of expert DBAs who set this parameter to true whenever they see any kind of shared pool / library cache latch contention.
On the other hand, spin_count was made an undocumented parameter long time ago, but is still heavily abused worldwide so I wouldn’t be surprised if the same happens to future _cursor_space_for_time…

Advanced Oracle Troubleshooting Guide, Part 6: Understanding Oracle execution plans with os_explain

Get ready for some more adventures in Oracle process stack!

Before proceeding though, please read this post about safety of different stack sampling approaches.

I have had few non-trivial Oracle troubleshooting cases, related to query hangs and bad performance, where I’ve wanted to know where exactly in execution plan the current execution is.

Remember, Oracle is just another program executing instructions clustered in functions on your server, so stack sampling can help out here as well.

So, I was looking into the following stack trace taken from an Oracle 10.1 database on Solaris SPARC, running a SQL with this execution plan.

Advanced Oracle Troubleshooting Guide, Part 6: Understanding Oracle execution plans with os_explain

Get ready for some more adventures in Oracle process stack!

Before proceeding though, please read this post about safety of different stack sampling approaches.

I have had few non-trivial Oracle troubleshooting cases, related to query hangs and bad performance, where I’ve wanted to know where exactly in execution plan the current execution is.

Remember, Oracle is just another program executing instructions clustered in functions on your server, so stack sampling can help out here as well.

So, I was looking into the following stack trace taken from an Oracle 10.1 database on Solaris SPARC, running a SQL with this execution plan.

Advanced Oracle Troubleshooting Guide, Part 6: Understanding Oracle execution plans with os_explain

Get ready for some more adventures in Oracle process stack!

Before proceeding though, please read this post about safety of different stack sampling approaches.

I have had few non-trivial Oracle troubleshooting cases, related to query hangs and bad performance, where I’ve wanted to know where exactly in execution plan the current execution is.

Remember, Oracle is just another program executing instructions clustered in functions on your server, so stack sampling can help out here as well.

So, I was looking into the following stack trace taken from an Oracle 10.1 database on Solaris SPARC, running a SQL with this execution plan.

Advanced Oracle Troubleshooting Guide, Part 6: Understanding Oracle execution plans with os_explain

Get ready for some more adventures in Oracle process stack!

Before proceeding though, please read this post about safety of different stack sampling approaches.

I have had few non-trivial Oracle troubleshooting cases, related to query hangs and bad performance, where I’ve wanted to know where exactly in execution plan the current execution is.

Remember, Oracle is just another program executing instructions clustered in functions on your server, so stack sampling can help out here as well.

So, I was looking into the following stack trace taken from an Oracle 10.1 database on Solaris SPARC, running a SQL with this execution plan.

Debugger dangers

Whenever I deliver training or conference presentations on advanced troubleshooting topics, I usually spend some time demonstrating how to get and interpret Oracle server process stack traces.

As I’ve mentioned before, stack traces are the ultimate indicators showing where in Oracle kernel (or whatever application) code the execution currently is (or where it was when a crash occurred). This is the reason Oracle Support asks for stack traces whenever there’s a crash or non-trivial hang involved, that’s why Oracle database dumps errorstacks when ORA-600’s and other exceptions occur.

There are multiple ways for getting stack traces for Oracle, but not all ways are equal. Some give you more contextual info, some less, but what I’m blogging about today is that some ways are less safe than others.