"Big O" notation for postgres?

["H. Hall" <hhall1001@xxxxxxxxxxxxxx>]

Does anyone know if there is a source that provides "Big O" notation for 
postgres's aggregate functions and operations?  For example is count(*) 
= O(1) or O(n)?

Do the developers for postgres use Big O when selecting algorithms? If 
so, is the info easily available?

Thanks,
HH




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H. Hall
ReedyRiver Group LLC
site: reedyriver.com