Why the database slows down and how to fix it: 5 business tips
Big business problems start with the few seconds a customer spends waiting on a company’s website. A user clicks «Search» or «Place Order» and instead of an instant result, they see a loading animation. During that time, they could be moving on to a competitor. A website loading delay of even 100 milliseconds can reduce conversion rates by 7%.
Big business problems start with the few seconds a customer spends waiting on a company’s website. A user clicks «Search» or «Place Order» and instead of an instant result, they see a loading animation. During that time, they could be moving on to a competitor. A website loading delay of even 100 milliseconds can reduce conversion rates by 7%.
Next is a direct speech by Illia Smoliienko, CEO Europe at Waites.
I have been working in the manufacturing analytics space for almost 10 years, where the speed of processing real-time data from IIoT sensors is critical to manufacturing efficiency. In this column, I will share my observations: what issues most often slow down query processing and how to optimize database performance so that customers receive instant results.
Challenges in working with large databases
Database performance is most often slowed down by errors in system architecture and maintenance. Here are the main ones:
Bottlenecks in SQL queries. Suboptimal SQL queries reduce performance. Use EXPLAIN analyses to see exactly how the database executes them. Replace nested subqueries with CTEs or window functions, cache repeated aggregations. A single line of code can speed up a query by dozens of times.
Unoptimized database structure. If indexes are created without taking into account queries, data types are chosen incorrectly, or there are redundant relationships, the database starts to lag. We have seen cases where a simple update of the table schema reduced the response time by three times. It is important to periodically audit the structure: what users are actually asking for, how often the data changes, and whether there are duplicate fields.
Poor data quality. Dirty, duplicated, or incorrect data creates an avalanche of checks that slow down every query. It is better to clean the information at the ETL/ELT stage or through streaming pipelines. Queries should only work with already checked tables — then both the speed and accuracy of the results will be stable.
Lack of computing resources. Even the best query optimization won’t help if the server can’t handle the load. When thousands of transactions are running simultaneously, CPU and memory quickly become bottlenecks. If your database is hosted in the cloud, you should enable autoscaling — this allows you to automatically increase resources during peak loads and reduce them when traffic drops.
Scaling issues. As data volumes grow, the number of parallel queries also grows. If the system does not have queues, connection pools, and limits on «heavy» queries, it may simply freeze. In transactional (OLTP) databases, this is critical: a delay of even half a second can cause a failure in the entire business logic.
How to maintain a stable data processing speed
To make your database run fast even with billions of records, you need to follow several principles:
Choose the right base. Database selection is a strategic decision that determines everything from system architecture to future support costs. A poorly chosen database becomes a problem that no amount of optimization or additional server can solve. If your business works with clear relationships, for example, customer, order, invoice, classic SQL systems are best suited. If you deal with dynamic content, user profiles or streams of unstructured data, you should consider NoSQL solutions. And when the main thing in your data is time (as in fintech, telecom or sensor analytics), it is more efficient to use databases optimized for time series. It often happens that a business with a hybrid architecture requires the implementation of a combination of several types of databases for its goals. The main thing is not to try to solve all the problems with one tool.
Optimize your queries. Regularly review how your queries are performing. Adding an index to a frequently queried column can speed up retrieval by a factor of ten. It’s worth creating an internal SQL review practice — it pays off quickly.
Balance indexing. Indexes speed up searches, but too many slow down writes. If you have a system with active data updates, don’t overload the database with unnecessary indexes. Remember that the optimal balance is an ongoing process, not a one-time adjustment.
Plan for scaling. Data volumes are growing faster than resources. Today you have terabytes, tomorrow you have petabytes. Cloud solutions like Amazon Aurora Serverless or Google Cloud SQL allow you to scale without stopping the system. The main thing is to build this capability into the design from the start.
Monitor productivity. Monitoring is not a luxury, it’s a necessity. Use Datadog, New Relic, Prometheus, or your own dashboards. They will show slow queries, CPU overload, or memory shortages before the user even notices them.
How it works in practice. Personal experience
Waites works with data from industrial sensors that record vibration, temperature, and dozens of other parameters in the operation of equipment every second. This is classic time series data that comes in constantly and has a time reference. At the initial stage, we used a file-based storage approach, organized in the form of a folder structure. But as the volume of data increased, this became inefficient: each request required scanning large volumes of files and took up to 10 seconds. If the client is monitoring how some equipment behaves, this is a long time for him.
To speed up processing, we first switched to InfluxDB and then to TimescaleDB, a PostgreSQL extension optimized for time series. It scales well and allows for data compression and archiving. The result was an 80% performance increase and query times down to 2 seconds.
It would seem that it was just a technical update, but it restored user trust and allowed the business to scale.
A fast database is a competitive advantage. When you’re working with billions of records, the key to consistent speed is to continually improve your architecture. The right database, query control, and scalability are the foundation of a productive system. This way, your data will work for the client, not just sit in storage.
Illia Smoliienko, CEO Europe at Waites
He specializes in developing solutions in the field of predictive maintenance of industrial equipment and the Industrial Internet of Things (IIoT) and has over a decade of practical experience in this field. For the Waites platform, he and his team built an ecosystem of 12 integrated client services from scratch and led the implementation of IIoT solutions for equipment condition monitoring at global companies, including DHL, Michelin, Nike, Nestlé and Tesla.