Practices That Improve MS SQL Server Query Performance

By Dzhingarov

MS SQL Server stands out as a very popular RDMS around the world. It offers countless features and benefits that lead to an efficient operation. However, this does not mean that everything would be perfect in the event that you do not use the very best practices. You need to improve query performance for your SQL server. Here is how you can do that.

Tune Your Queries

If you want to increase SQL performance, you have to tune queries. Remember that database functions can be inefficient. Two queries can seem similar but when you execute them, you see different results. Oftentimes, the difference is in the structuring. This is why when you build SQL databases you should work with experts or consultants.

Besides the structure of the query, you also have to focus on:

  • Identifying the relevant stakeholders
  • Focusing on the business outcomes
  • Asking the right questions so you can develop proper requirements
  • Creating specific requirements that are then confirmed with the stakeholders

Add Memory

Almost always, SQL Servers are assisted by adding memory. Performance is increased. SQL Servers can use memory in various different ways, like with:

  • Buffer cache
  • Buffer pool
  • Plan cache
  • Matching and sorting data

There are queries that require a lot of memory for sorts, joins, and several other operations. The more data is aggregated, the more SQL memory is needed.

Index Maintenance

If you want increased SQL Server performance, indexes are very important. The problem is that these do degrade as time passes. In many cases, this happens because of fragmentation. This means that data is not contiguously stored. Your system needs to go through numerous fragments in order to retrieve the needed data.

Two fragmentation types exist:

  • Internal Fragmentation
  • External Fragmentation

Extra Flash Drives Or Spindles

Similarly with the increase in memory, it is beneficial to increase storage capacity. The addition of the SSD, which is the most expensive opportunity, will benefit because of the lack of moving parts. An option that is less expensive is the addition of spindles. Use this to decrease latency times.

Optimize I/O

SQL Server performance is directly connected with I/O subsystem optimizing. As the new server is configured or when you modify the existing system, always determine the appropriate I/O subsystem capacity. This should be seen as being proper practice.

Three metrics are very important when you measure the performance of the I/O subsystem. They are:

  • Latency
  • Sequential throughput
  • Operations per second