Reply to post: Look first at the problem

Look first at the problem

Often a huge speedup can be obtained by spending a few minutes thinking about the problem before starting the design.

Many years ago the company that I was working for needed to do a lot of computation on a few days values from an Oracle database that had multiple years of data. The code that the consultants came up with worked - but would have taken over 2 weeks to produce the results as the main table was joined to itself in the query in a way that negated the speedup of the indexes. A bit of thinking and a much smaller table was produced by selecting only the required days from the main table and running the query using that table instead. That reduced the time required from over 2 weeks to under half an hour.

Another system was monitoring temperatures in a power station - the original spec had all the temps being monitored every second which was too much for the low performance mini computer of the time (early 1980's). A bit of looking at the items being monitored showed that many did not need a high scan rate (if the concrete pressure vessel temps are changing significantly in under 30 secs then it is well past time to run like hell!!). Changing the spec so that only the required items were scanned at high speed made the job easy for the computer to handle.

If you have a job that is going to heavily load a computer system then it is often worth spending some time to try to understand the problem (not just the spec) and see if there is any obvious inefficiencies in the spec that can be easily mitigated before starting coding.