以下是版工整理出的一些数据库规划、SQL performance tuning 简单心得,让长年钻研 .NET、AJAX、一堆高深 ooxx framework,却无暇研究 SQL statement 的程序员,透过最短时间对本帖的阅读,能避免踩到一些 SQL 的性能地雷。 (注:本帖的 SQL 语句皆经过测试可正常执行无误。有兴趣实验者,可直接拷贝后,粘贴至 SQL S...
以下是版工整理出的一些数据库规划、SQL performance tuning 简单心得,让长年钻研 .NET、AJAX、一堆高深 ooxx framework,却无暇研究 SQL statement 的程序员,透过最短时间对本帖的阅读,能避免踩到一些 SQL 的性能地雷。 (注:本帖的 SQL 语句皆经过测试可正常执行无误。有兴趣实验者,可直接拷贝后,粘贴至 SQL S...
以下是版工整理出的一些数据库规划、SQL performance tuning简单心得,让长年钻研 .NET、AJAX、一堆高深 ooxx framework,却无暇研究 SQL statement的程序员,透过最短时间对本帖的阅读,能避免踩到一些 SQL 的性能地雷。 (注:本帖的 SQL 语句皆经过测试可正常执行无误。有兴趣实验者,可直接拷贝后,粘贴至 SQL Serve...
Knowing about SQL Server’s new features will always put us one step ahead in our SQL performance tuning processes. Learn the Usage Details of the sp_whoisactive Thesp_whoisactiveis a stored procedure that allows us to view information about currently running queries and ongoing processes in t...
In this recipe, we first created and configured our trace by executing a T-SQL script. The script first declares some required variables whose values are passed as parameters to system stored procedures. It creates a trace by executing the sp_trace_create stored procedure that returns ID of th...
12. Utilize stored procedures A stored procedure is a set of SQL commands we save in our database so we don’t have to write the same SQL repeatedly. We can think of it as a reusable script. When we need to perform a certain task, like updating records or calculating values, we just...
When tuning, we start with the hardware and work our way up the stack, finishing with the application's SQL queries. The workload-dependent aspect of tuning gets higher as we move up the stack, so we begin with the most general aspects and move on to the most workload-specific aspec...
See "Collecting Statistics" in this chapter.You use the FIRST_ROWS(n) in cases where you want the first n number of rows in the shortest possible time. For example, consider the following PL/SQL block that uses a cursor to retrieve the first 10 hits of a query and uses the FIRST_...
SQL Server can recompile individual statements within a procedure or the entire procedure. Thus, to find the cause of recompilation, it’s important to identify the SQL statement that can’t reuse the existing plan. Analyzing Causes of Recompilation# ...
Java performance tuning tips relevent for tuning JDBC usage. The top tips are: Use prepared statements. Use parametrized SQL. Tune the SQL to minimize the data returned (e.g. not 'SELECT *'). Minimize transaction conflicts (e.g. locked rows). Use connection pooling. Try to combine...