Archive for the ‘PBXT’ category

MySQL Magazine – Winter 2009 Released!!

February 10th, 2009

This is one of the largest issues so far.  In addition, it has some of the best content we have ever had. The articles are all in-depth with some exciting new information:

  • Introduction to XtraDB: an overview of the new XtraDB storage engine along with benchmarks and information about planned future improvements
  • Changes in the MySQL DBA and Developer Exams for Version 5.1: what’s coming in the new exams covering MySQL Server 5.1
  • Covering Indexes in MySQL: how to create indexes that optimize query execution
  • PBXT’s Coder’s Guide: going in-depth on how you can work with the code for the new PBXT storage engine
  • Coding Corner: Peter’s regular column continues his look at transaction time validity

It is available for download, along with all previous back issues, at http://www.mysqlzine.net.

PBXT Transactional Characteristics

July 24th, 2008

Let me first say that the PBXT storage engine has some great people behind it. At the users conference last April, I had a chance to meet Paul McCullagh, who created PBXT, and some of the people who work on it. They are dedicated individuals who are creating something unique.

Like the InnoDB storage engine, which is backed by the Innobase company, PBXT has a company that backs it, Primebase Technologies. This means that if needed, support can be got from the company that created the product. For enterprise companies this might be important.

The basics characteristics of PBXT:

  • MVCC: Multi-version concurrency control, enables reading without locking.
  • Transactional: Support for BEGIN, COMMIT and ROLLBACK and recovery on startup.
  • ACID compliant: Atomic, Consistent, Isolated, Durable (once committed, changes cannot be lost).
  • Row-level locking: updates use row-level locking, allowing for maximum concurrency.
  • Deadlock detection: immediate notification if client processes are deadlocked.
  • Referential Integrity: foreign-key support.
  • Write-once: PBXT avoids double-writes by using a log-based architecture.

Much of this is the same as for the other transactional storage engines, so I won’t spend time on them. What sets PBXT apart from other storage engines is the write-once characteristic. It is worth understanding.

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