When working with SQL Server databases, it is important to consider the size of your database tables. As data continues to grow, tables can become too large, leading to performance issues. In this article, we will discuss some practical tips to reduce SQL Server database table size and improve performance.
Rule #1 – Minimum Redundancy of Data Types
The size of SQL Server data storage is based on pages, with each page being 8 KB in size. The more compact data types you use, the fewer pages are required to store the data. This results in fewer I/O operations and improved performance.
For example, let’s consider a table that stores working days of employees. The initial data types used in the table may not be the most suitable. By selecting more appropriate data types, such as using SMALLDATETIME instead of DATETIME and INT instead of BIGINT, you can significantly reduce the table size and improve query performance.
CREATE TABLE dbo.WorkOut2 (
DateOut SMALLDATETIME,
EmployeeID INT,
WorkShiftCD VARCHAR(10),
WorkHours DECIMAL(8,2),
CONSTRAINT PK_WorkOut2 PRIMARY KEY (DateOut, EmployeeID)
)Rule #2 – Use Database Normalization and Avoid Data Duplication
Database normalization is a technique that helps eliminate data duplication and improve data integrity. By storing unique profiles in a separate table and using a hash to identify sets of options, you can reduce the size of the table and simplify queries.
For example, instead of storing formatting options for each SQL code formatting session in a single table, you can store unique profiles in a separate table and reference them using a hash value. This not only reduces the size of the table but also improves query performance when retrieving popular formatting styles.
Rule #3 – Be Careful While Selecting Indexed Columns
Indexes are used to speed up data retrieval from tables. However, it is important to be careful when selecting indexed columns, especially for clustered indexes. All the columns included in a clustered index are also included in every non-clustered index, which can significantly increase the size of the database.
Rule #4 – Use Consolidated Tables
If you frequently execute complex queries on large tables, consider creating consolidated tables. These tables store aggregated data from the original table, allowing you to execute simpler queries on smaller tables. This can greatly improve query performance.
Rule #5 – Every Rule Has an Exception
While it is generally recommended to use compact data types, there are exceptions. For example, the BIT data type in SQL Server optimizes storage and can reduce disk I/O. However, it is important to note that retrieving data from BIT columns requires additional CPU resources.
Rule #6 – Delete Data That is No Longer Required
Regularly deleting data that is no longer required can help optimize performance. SQL Server’s read-ahead mechanism anticipates data and index pages needed for query execution. By removing unnecessary data, you can reduce disk I/O and improve performance.
By following these practical tips, you can reduce the size of your SQL Server database tables and improve performance. Remember to carefully select data types, normalize your database, be cautious with indexed columns, consider using consolidated tables, and delete unnecessary data. These steps will help optimize your SQL Server database and enhance productivity.