Richard To

How to speed up multiple aggregation functions apply to the same table

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 ...
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Richard To

Bind Sensitive SQL May Also be Place Sensitive

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 another place. If your SQL has bind variables...
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Richard To

Real Workload Based Index Advisor Works on a Complex Environment - Toad Xpert SQL Optimizer

Here is a case study that I would like to share with our users: " This enterprise data system is part of what makes...
882 0 /
Richard To

SQL Rewrite to Twist Cost Estimation

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 Cost estimation error The cost estimation error is not only caused outdated statistics, but lots of other factors that a SQL's...
1158 0 /
Richard To

A New Test Run Wizard for SQL Optimizer for Oracle

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 specific SQL performance problems. We will soon...
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