Exasol, from the company of the same name in Nuremberg, is presented by the vendor as a high-performance in-memory analytics database that aims to transform how organizations works with data, on-premises, in the cloud or both.
Exasol is well suited for data warehousing, BI, ML, AI - all analytical queries. It has almost no operation cost, because it is selfmaintening the indexes etc.
Microsoft SQL Server is ideal for highly available SQL workloads by using SQL Server Always On availability groups. Microsoft SQL Server might not be appropriate for solutions which require a very low resource footprint, since it requires significant CPU cores and RAM memory as well as high IOPS, always depending on the usage scenario.
We have found Exasol to be very fast at summarizing large data sets. It has been a great backend for both reporting tools and data analytics/business intelligence. Combined with the fact that data import is also very fast it makes it ideal for a real-time ELT architecture.
Exasol is low maintenance. No indexes to maintain (The database auto-manages them) and very little tuning is required.
Query processing is optimized for high throughput and high parallelization. This means that even under high loads performance degrades gracefully as opposed to having "pile-ups" and "meltdowns". This has made it a very reliable database for us.
I think it is unlikely that sql server has disappointed someone, it is likely that someone will come initially discouraged if the needs and problems that occur are very challenging, but definitely have a SQL oriented system means having a solid base to work and on which maintain the their data securely
SQL Server mostly 'just works' or generates error messages to help you sort out the trouble. You can usually count on the product to get the job done and keep an eye on your potential mistakes. Interaction with other Microsoft products makes operating as a Windows user pretty straight forward. Digging through the multitude of dialogs and wizards can be a pain, but the answer is usually there somewhere.
I have had only positive experiences with their support. They are fast, knowledgeable, and courteous. Online support requests get picked up within hours. I've only once had to use their hotline and that was for an emergency. There was even one minor non-security bug report that I reported and which they fixed in the following week's minor release. I was quite impressed.
We managed to handle most of our problems by looking into Microsoft's official documentation that has everything explained and almost every function has an example that illustrates in detail how a particular functionality works. Just like PowerShell has the ability to show you an example of how some cmdlet works, that is the case also here, and in my opinion, it is a very good practice and I like it.
Other than SQL taking quite a bit of time to actually install there are no problems with installation. Even on hardware that has good performance SQL can still take close to an hour to install a typical server with management and reporting services.
We looked at some others too, but was 5 yrs ago so I don't recall the list. Exasol had the best performance per cost, outstanding performance, and was easy to evaluate. Even their community addition running on my laptop was faster than our existing reporting solution.
Microsoft SQL is slower than MySQL and Access but far more feature-rich and reliable. Access is almost obsolete nowadays, so not too many people are considering it, but unless budget or an open-source ethos is a factor, Microsoft SQL is superior in every way. Many commonly used tools, like Crystal Reports, support it.
Increased accuracy - We went from multiple users having different versions of an Excel spreadsheet to a single source of truth for our reporting.
Increased Efficiency - We can now generate reports at any time from a single source rather than multiple users spending their time collating data and generating reports.
Improved Security - Enterprise level security on a dedicated server rather than financial files on multiple laptop hard drives.
