Re: cardinality() - Mailing list pgsql-hackers

From Grzegorz Jaskiewicz
Subject Re: cardinality()
Date
Msg-id 625B8158-CCE7-4D84-ACE1-6D1964145018@pointblue.com.pl
Whole thread Raw
In response to cardinality()  (Andrew Dunstan <andrew@dunslane.net>)
Responses Re: cardinality()  (Andrew Dunstan <andrew@dunslane.net>)
List pgsql-hackers
On 1 Mar 2009, at 00:52, Andrew Dunstan wrote:

>
> We seem to have acquired a cardinality() function with almost no  
> discussion, and it has semantics that are a bit surprising to me. I  
> should have thought cardinality(array) would be the total number of  
> elements in the array. Instead, it seems it is a synonym for  
> array_length(array,1). Is that *really* what the standard says?

any difference between array_upper(array,1), and cardinality ?
Standart just says something like:

cardinality (a collection):
- The number of elements in that collection.
- Those elements need not necessarily have distinct values.
- The objects to which this concept applies includes tables and the  
values of collection types.






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