Tag: performance

Short summary: Queries to ALL_SYNONYMS cause FTS of SYS.OBJ$ which can’t be avoided.

Introduction Every new version of SQL Server ships with exciting new features. One of the simplest but important features is Automatic Tuning. Before covering this new feature, let’s analyze the old ways so we can understand what is really automated…

For the Oracle Code series of events I have delivered an older but still relevant talk called “Tackling Time Troubles.” Half of it is nice-to-know geek trivia and the other half is a few points on how to avoid very…

Having good historial metrics monitoring in place is critical for properly operating, maintaining and troubleshooting database systems, and Percona Monitoring and Management is one of the options we recommend to our clients for this. One common concern among potential users…

If you’ve ever had to evaluate server performance, you likely know of sysbench, a performance benchmark project started by Peter Zaitsev with continued development by Alexey Kopitov. The last official release was the version 0.4, which is found in almost…

It’s well known that mmap helps to improve performance in particular use-cases (especially if your working set fits an available memory). This doesn’t mean that the file itself has to fit memory. mmaps provides real benefits over the other IO…

One of the interesting features introduced in MySQL 5.7 is that innodb_buffer_pool_size is a dynamic variable (since 5.7.5, to be more specific). Yet, past experience tells us that just because a variable is dynamic, it does not make it is…

Parallel execution in Oracle seems to be a topic of myths, mysteries and misunderstandings. In this post I hope to clear up at least one of them by diving into a discussion about parallel DML. Actually, I want to show…

MongoDB’s database profiler lets us collect some performance data about operations happening on a MongoDB instance. In this post, I will show you how we can enable the profiler, what kind of information it can store for us, how to query this…

Who here takes the time to adjust default values for SQL Server Configuration after installing it? Unless your company has specific Post-Installation Tasks procedures/document, SQL Server configurations are left as is until an issue comes along. If you are doing your…