Analysis General Principles |
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The Analyser works by flowing data through a number of steps, using special operators, each of which performs specific functions:
Firstly, each analysis has its own properties – a name and description and, optionally, user defined parameters.
Parameters are placeholders, so that, instead of an analysis having to be changed each time it is run to extract the correct data, a parameter is set up.
For example, a parameter called CurrentYear could be defined and used in appropriate places in the analysis, instead of hard coding the actual year. Then, when the analysis is run, the user is prompted to enter the correct year of the data being extracted.
The Source operator provides a raw stream of data from the database, with users applying filters or selection parameters. Each analysis must have a Source operator as the starting point, from which data is piped sequentially to other operators.
Data may be fed into an intermediary operator, these being more advanced operators. Therein the data is manipulated and then piped out, either to another intermediary operator, or to an output operator, eg a Print operator. The five intermediary operators, each of which has a specific function and usage, are:
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Every analysis must end with one of the two output operators: a Print operator or Export operator.