When it comes to MySQL, slow performance in large tables is one of the main sources of complaints. It is true that some users face problems as their database fails to sufficiently handle a more than a certain number of rows.
However, there also are many corporations that use MySQL for millions, even billions of rows of data and yet they successfully deliver excellent promise. So, why is there a contradiction between these two cases? The answer lies in understanding the intricacies of table designing in MySQL, and with the help of MySQL SQL performance tuning, how to make them work in your favour.
What to Consider During MySQL SQL Performance Tuning
There are three major aspects of the database that can have an impact on databases with huge amounts of data. Let’s take a look at two of them now:
The first thing to consider with any database management system is that you must have an estimate of the memory, even as you progress in terms of data accumulation. It is important for the memory to be sufficient because performance suffers greatly if it isn’t, so don’t be surprised if a drop in performance is greater than you anticipated because you may have lost track of the growth in data size and subsequently, the need for more memory space. This applies to the other aspects covered in this blog as well. Once data outgrows the memory, everything can be expected to slow down, and MySQL database and SQL becomes a necessity.
One way to ensure the memory remains sufficient for your data is to practice data partitioning. In this process, old data that is no longer required as often as recent data, is separated and stored in other servers. There are various other ways of ensuring sufficient space which we will talk about in another blog.
Indices, or indexes, are known by most of us to be a useful tool in improving the accessing speed of the database. An important thing to remember is that their usefulness depends a lot on exclusivity, i.e., the ability to select a number of rows that match with specific index ranges or values. Also, the nature of the workload – specifically whether it is cached or not – determines how much it will benefit from the use of an index.
This is actually overlooked by even MySQL optimizer at present and may need to be checked by other MySQL SQL performance tuning tools. Workload indices have a chance of much quicker access even if the size of the data being accessed is as large as fifty percent of the entire number of rows, as long as they are in-memory. On the other hand, for disk IO bound access, you may have greater success in fetching data through a full table scan irrespective of the number of rows you are requesting access to.
Since indices can differ from each other in many ways, they need to be used differently in order to effectively use them. For instance, you can place them either in a well-organized manner or at random spots, resulting in significant changes in their speed. Innodb also includes clustered keys which work by merging data and index access – such keys end up conserving IO that will prove invaluable for workloads that are entirely disk-bound.
Designing table structures smartly involves taking into consideration all the abilities and disabilities of MySQL. This is especially important if you have to handle different kinds of databases in your organization.
The main reason why your organization has different databases in the first place is because of their different capabilities and shortcomings. So, the same design concepts won’t bring the same results in say, MS SQL or Oracle that they did in MySQL and vice versa. The same is true for their storage engines – each can have a different effect on the performance.
Once you have applied the right application architecture to plan your tables, you will be able to create applications that can easily handle huge data sets on the basis of MySQL.
Proper MySQL SQL performance tuning involves optimizations that can greatly boost the rate at which indices are accessed or scanned. There already are tools by Tosska Technologies Limited for this purpose like Tosska SQL Tuning Expert (TSEM™) for MySQL which you can download and start using today. Contact our team for further information or enquiries.