Anyone who has to keep an SQL Server instance up and running will doubtlessly encounter issues that need to be dealt with to restore performance to its optimal level.
The first step to effective troubleshooting in this context is knowing what problems to look out for, so here is a rundown of conundrums that arise frequently and a few hints on how to fix them.
If you come across deadlocks in SQL Server, it is a sure sign that processes are attempting to use the same database objects and are prevented from jumping from one resource to another because of this concurrency conflict.
There are a few ways to deal with this, such as by tweaking the order of operations so that the processes which created the deadlock in the first place execute in an order that limits the likelihood of the deadlock reoccurring in the future.
It is also worth pointing out that deadlocks are an essential part of preserving data integrity and overall database operational effectiveness, so they are not fundamentally bad, but rather can be seen as a symptom of some other inefficiency.
A well-maintained SQL Server setup should have carefully corralled indexes which help to catalyze the storage and retrieval of large volumes of information over time.
Of course, the crucial role that indexes play in a database also means that if they are managed imperfectly, then performance will suffer.
It is all about getting the balance right; if you are over-indexing then you could slow down queries unnecessarily and monopolize storage space without seeing any benefit, while if your indexes are outdated or missing altogether then it might take longer to find the right data.
Regularly auditing your indexes and working towards a curated configuration that works for your needs is the best way to avoid issues running riot.
Providing a temporary repository for data within SQL Server while it is in use, TempDB is another lynchpin feature that can often be the source of woes for administrators.
In particular, performance problems can be the result of TempDB filling up because data is not correctly being culled after the process which needed it has completed. Being on the lookout for the storage limit of TempDB being close to maxed out is a sensible step, as this will be an indication of action n being required.
If SQL Server is not performing as it should be, the network connection could be the culprit, especially if you are relying on a remotely hosted instance rather than one which is based in-house.
Detecting a connectivity conundrum is not always easy, but one thing to look out for is response times that take 15 seconds or longer, as this will allow you to distinguish this from other types of performance issues.
Your next steps if connectivity is the culprit will vary depending on whether the source of the issue is local or on the host’s end. Often, just being able to pinpoint and provide evidence of a problem like any of these mentioned above is a solid starting point.