Check the Hardware

To check the Hardware, open the Task Manager and click on the Performance tab. This will show you how much of your CPU, memory, and disk resources are being used. If your database is using a lot of resources, it may be time to upgrade your hardware.

Check if the CPU is overloaded

If the CPU utilization is above 80% for sustained periods of time, you might want to consider adding additional CPU capacity. If the system is I/O bound, you might want to consider adding additional disk drives.

Check if the RAM is sufficient

Check if the system has enough RAM to maintain smooth performance of the database. If the RAM is insufficient, the database will start to use up hard disk space to store data, and this will decrease performance.

Check if the hard disk is overloaded

The hard disk is one of the most important components of a database server. If the hard disk is overloaded, it can severely impact the performance of the database.

There are a few things you can do to check if the hard disk is overloaded:

• Use the Windows Task Manager to check the performance of the hard disk. If the disk is working at 100%, it is likely overloaded.
• Use a tool like Sysinternals Process Monitor to monitor disk activity. This can help you identify which processes are causing high disk activity.
• Use a tool like Sysinternals Process Explorer to monitor disk usage by process. This can help you identify which processes are using a lot of disk space.
  Check the Database
  
  Check if the database is properly designed
  If the database is not designed properly, it will not work properly. To check if the database is properly designed, look at the following factors: -Data redundancy: There should be no duplicate data in the database. All data should be stored only once. -Data integrity: The data should be consistent and accurate. -Ease of use: The database should be easy to use. -Performance: The database should be able to handle the required number of users and transactions.
  Check if the database is indexed properly
  
  To check if the database is indexed properly, run the query below on your MySQL database.

EXPLAIN SELECT * FROM YOUR_TABLE;

The output of this query will show you how the database is indexing your table. If the database is not indexing your table properly, it will impact performance.

Check if the database is being used efficiently

Usage of a database can be checked in several ways, below are some of those with a short description.
-Table Scan: A table scan is usually the most expensive type of query, as it requires the database to scan every row in a table to find the desired data. This can be avoided by indexing appropriately.
-Missing Indexes: Missing indexes are indexes that could speed up queries but don’t exist in the database. Identifying missing indexes can be done by running the DMVs or using a third-party tool.
-Index Fragmentation: Index fragmentation is when an index is not stored contiguously on disk, which can cause performance issues as data is spread out and needs to be read from multiple pages. This can be fixed by rebuilding or re-organizing indexes.
-Unused Indexes: Unused indexes are indexes that are taking up space and resources but are never used by queries. These should be dropped to improve performance and reduce costs.

• tempdb Contention: tempdb contention is when multiple processes are trying to access tempdb at the same time, which can cause performance issues. This can be fixed by increasing the size of tempdb or adding more tempdb files.
  Check the Application
  In any given database environment, the application is the largest consumer of resources. SQL Server provides a wealth of dynamic management views and functions that can be used to identify which parts of the application are consuming the most resources. In this section, we’ll take a look at how to use these DMV’s to identify areas of the application that may need to be optimized.
  Check if the application is properly designed
  
  One of the most important aspects that will affect the performance of your database is the design of your application. A well-designed application will be able to take full advantage of the features of the database, and will make sure that data is accessed in the most efficient way possible.

There are a few things that you can check to see if your application is properly designed:
-Are you using indexes effectively?
-Is your data properly normalized?
-Are you using prepared statements when accessing data?
-Are you using caching effectively?

Check if the application is making proper use of the database

There are certain design patterns that are very common in applications which often lead to suboptimal performance. Some of these design patterns are:

• Opening and closing database connections for each database operation. This leads to a lot of overhead and can reduce the performance of the application significantly. The connection pooling feature of the database should be used to minimize this overhead.
• Creating multiple transactions for each database operation. This again leads to a lot of overhead and can reduce the performance of the application significantly. The database should be designed in such a way that there is only one transaction per database operation.
• Not using prepared statements or stored procedures for database operations. Prepared statements and stored procedures can improve the performance of an application by reducing the amount of data that needs to be transferred between the application and the database.
• Accessing data from the database which is not required by the application. This leads to unnecessary data being transferred between the application and the database which can reduce performance. The SQL queries used by the application should be carefully written to ensure that only the required data is accessed from the database.
  Check if the application is properly tuned
  Perform the following actions to check if the application is properly tuned: -Open the Performance Monitor. -Click + and select the appropriate counters under “Database Instances”. -Click Monitoring > Options > Include All Instances. -Click Run Query. -Check the “DB Time” counter and make sure it is below 50%. If it is not, check the other database counters to see where the time is being spent.