Oh that was just an example...Let me make a real example:
I have a table "Sensors" (that has to contain different sensor types) with a Value. That value doesn't have to be fixed, but I want to define it in a way that it changes its structure when the sensor type changes. For example, for Temperature sensor I would like to have just a float number, but for the humidity I could need of absolute and relative humidity (2 floats). I'd just like to know if I can say that the VALUE is a composite type...that I have then to specialize in Temp Type and Humidity type...using them in their particular case.
2009/6/5 Rob Sargent
<robjsargent@gmail.com>I'm not sure how Temperature and Humidity are related as types beyond "extends float". i.e. What tuple definition could alternatively have a Temp or a Humidity value? (I do understand their physical relationship :) ) Gianvito Pio wrote:
Hi all,
I just want to ask you if it's possible to define sub types in PostgreSQL (Type inheritance). I found that table inheritance is possible...but I'd like to do it on types.
Example:
define a type Value and two subtypes Temperature and Humidity and then define a table that has an attribute of Value type (that can accept both specialized types).
Thanks
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