It is standard wisdom that if you want a database to perform well then you carefully design a set of indices for the tables. Thus, by careful design of the database tables based on their contents and the common queries you can build a database that performs well. The index structures make such a difference that if they are not used on tables with large numbers of rows the performance is unusable. When this approach works then it works really well. There are problems, however, in environments that can lead to real issues, though I won’t go into detail here. Continue reading ‘Does a large database need an index?’ »
Posts tagged ‘volume’
Last year (in this article) I asserted that monitoring of all user operations on an on-going basis was highly valuable. At the time I was not aware of any automated tools to do this task, meaning that solutions would need to be implemented on a per-application basis. In the worst case, this could mean laboriously adding logging statements into application code and then providing analysis mechanism to extract meaningful information from this logging. Continue reading ‘Monitoring all user interactions’ »
Let us assume that you have started a piece of performance modelling. You have chosen a set of key transactions, or better still have been told what is most important by the business. You may have an idea of the performance levels that the business need (more on this another time), and you start working with the business to work out the volumes that they are expecting to put through the system. To do the appropriate performance modelling you will need to define the behaviour of a “typical user” and then scale this up to produce a total behaviour profile for all users. It is unfortunate that you are unlikely to receive figures that can be used directly from your business users. You have the following choices at this point: a) educate them in the modelling you are doing and the format you need the numbers in, or b) take the numbers they have provided and reproduce them from your modelling. Continue reading ‘Business volumes and performance modelling’ »
