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 ‘network’
A strategy that is commonly employed at present and which often seems strange on first sight is the use of storage servers. This is common, and is often justified for a host of reasons centring around the management of the data on the disks. It is strange, however, that it is also claimed to improve performance, rather than being implemented at the expense of performance. It common to assume that to improve performance you should remove client-server network hops, and network storage goes against this. Can it be true, or is this a myth? Continue reading ‘Local disks vs Storage server’ »
The following story illustrates why capacity management is needed to consider the most appropriate action to improve performance. I suspect you could insert any resource you wish in place of “network” and the assertion would still be valid.
Firms waste billions on network over-design
Who needs desktop Gigabit Ethernet anyway?
http://www.theregister.co.uk/2006/05/22/network_overdesign_gartner/
It is true that simply upgrading hardware until the system performs well can look like an effective solution in many cases. It can avoid often complicated analysis and testing work, and in many cases will be effective in the short term. Simply continuing to throw hardware at problems as a strategy, however, doesn’t really work. The issue is that solving a solution in this manner will generally be a short term fix. If the solution continues to be to keep adding more resources then eventually the costs stack up to be unacceptable. In many cases there will also be a point of diminishing returns where even the best hardware on the market will fail to keep up. A more informed decision can be made by characterising a system and estimating the capacity that may be required to meet future requirements.
