Guide and Checklist for SQL and Database Performance Tuning: Professional Advice.

SQL and Database Performance Tuning Guide and Checklist: Expert Tips

Database Performance Tuning. A racing mechanic is similar to a database administrator (DBA). Building and optimizing a high-performance car requires minute adjustments and attention to detail. A small change here and there could reduce your lap time by a few hundredths of a second. That tenth of a second could make the difference between winning and losing the race.

You, the DBA, are in charge of optimizing your SQL queries to give them more strength. Even a slight increase in speed could put you ahead of your rivals and establish you as a victor in your client’s eyes.

Even though you don’t become an expert in SQL performance tuning overnight, there are some guidelines to remember as a cloud DBA just starting. As your skill set and knowledge base expand, this manual will provide you with a solid foundation to build. You will pick up some essential trade secrets, such as organizing associated metrics and thinking in buckets.

A checklist of database maintenance chores and a free trial of SQL tuning tools are also provided.

1. What is SQL Performance Tuning?

Starting with a precise grasp of SQL performance optimization and what you are attempting to achieve may be helpful.

The practice of enhancing the queries running within your database to produce the desired results as quickly and efficiently as feasible is known as SQL performance optimization. Finding the quickest/cheapest way to return the same results may be done in dozens of different ways, which is what SQL performance tuning is all about.

In SQL tuning, there isn’t a single magic solution. The ideal practice in one context might not be appropriate in another. Consider the differences between OLTP and OLAP/data warehouse databases in terms of their intended function and size (think gigs vs. teras). Testing, recording the results, and then testing again is a continuous process.

When performing jobs involving performance tweaking, it’s crucial to:

1. Think in categories;
2. Pay attention to associated metrics;
3. Analyze outcomes throughout time;
4. Maintain a database consistently.

​​2. Think in Buckets

Choosing where to begin when faced with the chore of database performance tuning can be challenging. You may be unsure of which area of your database needs improvement right now. While discussing managing a database in the cloud, you might need to consider several factors that weren’t as important when your database was on-premises. Database Performance Tuning.

The ideal way to create your action plan is to think in terms of categories. Analyze your database as a mechanic would a freshly repaired vehicle. Since looking at everything at once is not particularly helpful, the technician prioritizes problems based on their function and location. Is there a suspension issue? The motor? Or is bodywork necessary? You may refer to these as the “buckets” of auto repair.

Separating potential problems into categories regarding database performance tuning entails classifying everything according to commonalities. The bins for databases and SQL optimization are as follows:

• Resources (real or virtual); 
• Indexing/Data model; 
• Query structure; 
• Concurrency (blocking; several threads asking for locks on the same database resource).

You can delve deeper into more “buckets” to find the issue’s origin. Consider resources as an example, as they can be the one item you need to pay extra attention to if your database is hosted in the cloud. The resource types listed below are some to take into account while trying to improve the performance of SQL statements:

• Memory, 
• CPU, 
• network, 
• and disk I/O.

We can further break down the other “buckets” in the same way, but we won’t get into those details because they don’t dramatically change when comparing on-premises and cloud solutions.

3. Focus on Correlated Metrics

You’ll be monitoring particular metrics as you test your queries and modify your database to quantify progress over time. These metrics could consist of:

• States of wait (where the database is spending time executing the query for the end-user);
• CPU use and signal waiting;
• Schedule a response time;
• Compilations of SQL statements;
• Transaction volume;
• Memory strain (latch contention and data flushed out of memory quickly);
• I/O latencies on disk;
• Network utilization and bandwidth (this is especially important for supporting databases in the cloud).

When deciding which metrics to utilize for correlation, use wait states as a reference. To determine whether those particular resources are the source of performance issues, look at memory pressure (why does your database need to go back to the disk so frequently?) and disk performance (read latency) as associated metrics. Blocking is a fantastic example as well. You cannot correlate CPU, memory, disk, network contention, or pressure if your database constantly waits for locks to be released.

Your best buddy when it comes to performance metrics is database analysis tools. Database Performance Analyzer’s dashboard feature offers a helpful look into the correlation of metrics. The context provided by multi-dimensional performance analysis allows you to analyze your data from several perspectives and identify the underlying causes of performance problems. You can get the who, what, when, where, and why answers you need from the multi-dimensional picture.

With rapid views of current and past events and performance information, DBAs may gain even more visibility across your Microsoft data estate with SolarWinds® SQL Sentry. SQL Sentry can also display execution plan diagrams, query history, and other information to identify and resolve potentially problematic queries quickly.

4. Measure Results Over Time

You must monitor your metrics throughout time to comprehend how your SQL queries are doing. You may comprehensively understand your database’s overall functioning by gathering data over a few weeks or even months. It will enable you to see the whole rather than just a picture of an individual event. It assists you in determining whether your performance is worse now than it has ever been. Tracking performance over time can serve as a benchmark for determining whether a certain period’s performance is out of the ordinary. An illustration would be to look at activities at the end of the month instead of just the previous week.

5. Database Maintenance Tasks

SQL tuning requires database upkeep since it allows you to identify potential issues and fix issues you might not have even known existed.

Several typical or general maintenance duties are advised, albeit they may vary depending on the environment.

Here are a few acronyms that every DBA has to be aware of before we get into the specific maintenance tasks:

• Service Level Agreements (SLA) (what you and the business end-user agree upon)
• Recovery Point Objective (RPO)
• Recovery Time Objective (RTO)
• Mean Time To Innocence (MTTI) is the length of time needed to demonstrate that the problem is not with the database.

Here are the key locations where you, as a DBA, need to undertake routine maintenance while keeping these acronyms in mind:

1. Backups must be performed to satisfy RPO/RTO/SLA goals, but how is dependent on the system. One strategy is to perform hourly transaction log backups, daily differential/incremental backups, and complete weekly backups (for SQL Server®) during regular business hours. It will provide security immediately, but it may not be suitable for all systems.

A 30PB database, for instance, is unlikely to require weekly full backups. It is also crucial to know how long it will take to get back to yesterday, last week, last month, or last year. It would help if you created a recovery strategy, then fit your backups into that strategy.

Remember, if you can’t tune your database environment, you might not receive a raise; however, if you can’t ensure you can restore, you WILL NOT HAVE A JOB.

2. Index upkeep – You should routinely, if not daily, examine your indexes. You might not want to rebuild indexes every night, though. Once more, it depends on the system and how long it takes to rebuild. The degree of index fragmentation may be such that stat updates or index reorganization are preferable to rebuilding the index.

3. Update statistics – Daily statistics checks are good. These checks rely on the system, how quickly statistics are updated, how frequently database objects (such as tables and indexes) are changed, and which queries will be required to recompile the following time they are executed.

4. Checks for corruption – You should make it a high priority to conduct checks for corrosion at least once a month.

5. Record configuration information – For the database and the server, you should record configuration information daily and track when changes are performed. It might be expanded to include other details like newly created or removed users, logins, user rights, etc. Each DBA’s dedication and desire to maintain a low MTTI will determine the level of detail.

Conclusion

As you can see, a cloud DBA has many of the same responsibilities and duties as a traditional DBA. Many of the methods and techniques we’ve used in the past to diagnose performance problems still apply today. Future DBAs will probably need to have a more comprehensive understanding of technologies. So brush off your networking knowledge and immerse yourself in the cloud.

About Enteros

Enteros offers a patented database performance management SaaS platform. It proactively identifies root causes of complex business-impacting database scalability and performance issues across a growing number of clouds, RDBMS, NoSQL, and machine learning database platforms.