If you want to find the minimum salary among all employees, you may issue a SQL statement like this: select min(emp_salary) from employee Plan 3 SELECT STATEMENT 2 SORT AGGREGATE ...
I have heard a lot of people ask "Why my SQL performance is vary depending on where the SQL is executed ?", sometimes you may notice that the same SQL is performing good in one place, but not good in...
Here is part of a case study that I would like to share with our users: "This enterprise data system is part of what makes Haas a leading global provider of chemical supply chain management(CSCM) sol...
There are mainly three problems that database SQL optimizer cannot find the best way to process your SQL statements. Cost estimation error The cost estimation error is not only caused outdated stat...
In SQL Optimizer for SQL Server we have built a very useful test run wizard (see my blog post Test Running a Tuned SQL is Not An Easy Job”) to help users select the best SQL alternatives for their spe...
In SQL Optimizer for SQL Server, we have built a very sophisticated test run facility for users to find the best SQL alternative from all generated SQL alternatives to solve the user’s specific proble...
A junior developer came to me recently and asked me a SQL transformation question. He gave me an example of a SQL statement similar to this one: select * from TableA A where A.KeyCol/10 = 12345 The p...
This blog is the finale in this series about common misconceptions surrounding SQL tuning. I selected this topic as my last one because it is a very common misconception in a DBA or developers mind. I...
Using SQL Rewrite mode in Optimize SQL consists of two steps. In the first step, SQL Optimizer generates semantically equivalent alternatives with unique execution plans for your original SQL statemen...
