For some SQL statements with multiple Max() functions in the select list and nothing in the Where clause, we have different methods to create new...
Here the following is the description of the ORDERED hint. The ORDERED hint causes Oracle to join tables in the order in which they appear in the...
Your end-users may keep on complaining about some functions of their database application are running slow, but you may found that those SQL...
It is not just another SQL tuning tool There are not many SQL tuning tools for SQL Server database, but most of them are focused on plan...
The following is an example shows a SQL statement with “Group by” expression. The SQL retrieve the sum of historical salary from table...
Here the following is a simple SQL statement with a “< ALL (Subquery)” syntax. SELECT * FROM employee a WHERE a.emp_salary <ALL(SELECT...
The following is an example shows an Update SQL statement with an “IN” subquery. It updates records from emp_subsidiary that satisfies the “IN”...
It is common that the performance is not good if a SQL statement with OR conditions. Let’s have an example show you how to tune those SQL...
It is common that we used to count the number of records in a table. You may encounter unexpected performance degradation in certain situations....
The LIKE is a logical operator that determines if a character string matches a specified pattern. A pattern may include regular characters and...
There may be some business requirements that need to compare certain part of a column as a data retrieval criteria. Here is an example SQL that...
There may be some business requirements that need to retrieve the first N number of rows from a join tables. Some people may encounter unexpected...
There may be some business requirements that needs to retrieve only some rows from a table (or join tables) randomly. This kind of SQL is normally...
There are at least two commonly used methods to improve an SQL statement’s performance. First, users can influence Oracle SQL optimizer to pick up...
SQL Patches is part of the features provided by SQL Repair Advisor which is used to fix a SQL statement’s critical failures such as returning...
A SQL statement with multiple aggregation functions like the following and the emps_salary and emps_id are indexed. If you find the SQL is slow...
A user who has a SQL statement takes a long time to execute, actually the SQL is not very complicated, but it has a very complex execution plan....
Introduction Application package software is a collection of software programs that is developed for the purpose of being licensed to third-party...
Common SQL tuning methods SQL tuning is the process to improve a SQL statement’s performance up to the user’s expectation. There are at least...
Separate names with a comma.
