if you’re just looking for stable, recent, binary MySQL Community release, you might not find it. MySQL offers two out of three — stable and binary Community releases. Not recent, but I think it’s okay to charge for the most up-to-date version. In my experience only about half of the production environments out there have switched to 5.0, and many are running 4.1 and 4.0 still.
We hit an ORA-01450 error today trying to do online rebuild for an index in an unusable state. This was a non-unique index on a fairly large column — VARCHAR2(800 CHAR). It rang a bell. I remembered that I encountered this issue a while ago, but I couldn’t recall the details. I know that it has nothing to do with the actual data size — it’s an error that can occur during index creation.
So, how does one gather statistics on indexes? With InnoDB it’s one thing, with MyISAM it’s another thing. This post however, will focus on MyISAM. There are various ways, each having their own drawbacks and positive sides.
We recently had an issue with a client while cloning a huge database. The result was that we had to restore the whole database as the post-clone corrupted the existing database. Pain! It took another fourteen hours to restore. This may help you to troubleshoot the issue.
Andrew Clarke has published to 104th edition of Log Buffer, the weekly review of database blogs, on Radio Free Tooting, marking LB’s second year. Happy Birthday, LB!
During my presentation at the TOUG meeting, I mentioned that when using 11g’s enhanced security settings or, at least, the audit setting, you risk the unlimited growth of the SYSTEM. Mohamed El-Shafie from Oracle quickly noticed that there is no auto-purge. I promised to have another look at the maintenance tasks in 11g to confirm that, and indeed, the audit trail is not purged automatically when auditing is enabled by default. Here is a quick remedy — scheduling an audit trail maintenance job.
Seems I have turned into a bit of a news source. dbWatch Software sent me a news release on their dbWatch monitoring platform, which looks like it might be an interesting product for those who work in a heterogeneous database environment. Here’s the release.
InnoDB is a storage engine that uses MVCC (described shortly) to provide ACID-compliant transactional data storage using row-level locking. MVCC stands for Multi-Version Concurrency Control. It is how InnoDB allows multiple transactions to look at a data set of one or more tables and have a consistent view of the data. MVCC keeps a virtual snapshot of the dataset for each transaction. An example will make this clear.
I was contacted by the folks at MONyog and asked if I would review MONyog. Since using MONyog is something I have been wanting to do for a while, I jumped at the chance. Of course, “jumped” is relative; Rohit asked me at the MySQL User Conference back in April, and here it is two months later, in June. My apologies to folks for being slow. Have a look.
I began to write a post on InnoDB transactions, but there was so much background material that I decided first to write a post introducing transactions, and then one on how InnoDB implements them. If there is good response from these two posts, I will continue with other posts on the major storage engines and their transactional characteristics.