When creating a schema, the following recommended practices should be followed:
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Units should be assigned to all properties that represent a physical quantity (e.g., length, area, volume, time, etc.). By assigning units, the meaning of these values are well understood and can be interpreted in only one way. This is particularly critical when properties are used in calculations. They are also required if unit conversions need to be done.
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Instance labels help identify and distinguish items in an i-model. Their use is particularly critical when working with models having a large number of items.
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Avoid assigning class, property and relationship names that exceed 64 characters in length if possible. If unavoidable, define and keep their display labels to 64 or less characters. Microsoft Access limits the length of field names to 64 characters. If the data in an i-model is exported to Access using the i-model ODBC driver or some other means, the field names will be truncated if larger than 64 characters. Though the ODBC driver will ensure the truncated names are unique, the abbreviated names may be difficult to work with.
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Calculated properties provide a concise and flexible method of concatenating values or performing math calculations involving one or more properties. These are particularly useful for creating business key and instance labels.