The Role of Table Design in SQL Query Performance Tuning

Database professionals write plenty of SQL queries to fetch a particular result from databases. Each different kind of statement is likely to offer different levels of performance. For this reason, DBAs have to pick the ones that provide the best performance and the quickest results. They can also optimize other queries by tuning them to improve performance during execution and data retrieval.

 

While working on SQL query performance tuning, you will have to consider the extent of improvement on the performance of each query. In fact, a lot of professionals believe tuning queries is more important than other components, such as software or hardware configurations that have an impact on performance. 

 

How to Maintain Query Performance with Proper Table Designing

 

Here, we will discuss some important things to remember while designing tables from a performance perspective in SQL Server. If you have read this far in search of Oracle performance tuning tips, you can refer to our other blogs and articles covering this topic. 

●      A primary key is a must-have for every table as it assists with updating, deleting, and fetching rows.

●      Always make the first column a primary one.

●   Conduct normalization in your tables to the 3rd form, known as 3NF. 3NF implies that the table is in 2NF without transitive dependencies. Doing this is necessary as it decreases duplication, leaving fewer tasks for the database to take care of, improving its performance.

●     Conversely, bring down the normalization or denormalize tables that are 4NF or 5NF to 3NF. Otherwise, it can result in performance degradation since you will need more joins for a lot of tables.

● Horizontal partitioning can help with SQL query performance tuning. This is particularly true in the case of extremely large tables for both in-use and archived tables.

●      Decreasing column quantity in tables also helps improve database performance. That’s because when a table has a low number of columns, it will obviously use less space in comparison with tables that have more columns. Moreover, a single data page will fit more rows, leading to lower processing to reach table information.

●   Give preference to constraints over rules, defaults, and triggers wherever you can. The reason behind this is the better efficiency of constraints that directly helps performance. They also show greater reliability and consistency.

●     Make use of the file system rather than blob data type when you require storage for sizable binary objects. This is because the server requires plenty of resources when it has to place large binary objects inside a table. This is similar to Oracle performance tuning tips as it uses extra resources as it reads rows to scan the information. When the database saves large binary objects in a file system, it simply makes use of extra tables. These tables don’t undergo scanning, so their presence doesn’t have a negative impact on database performance.

 

Summary

Regardless of the quality or capacity of the hardware, the speed and output of your database server can take critical hits from a bunch of bad queries. In fact, a single bad query can prove enough to make the database perform poorly.

The above-mentioned list contains some useful techniques you can carry out to uncover queries with poor performance. You can then proceed with SQL query performance tuning to improve their performance. You can make great improvements with proper table designing and by tuning the costliest or most frequently-used queries.