Re: [GENERAL] The semantics of (NULL,NULL) vs NULL

2012-08-02 Thread Kevin Grittner
Ingmar Brouns wrote: > Can anyone explain why: When it comes to record types, IS NULL is defined to mean "there is no record or all elements of the record are null". NOT NULL is defined to mean that *all elements* of the record are not null. -Kevin -- Sent via pgsql-general mailing list (

Re: [GENERAL] The semantics of (NULL,NULL) vs NULL

2012-08-02 Thread Peter Geoghegan
On 2 August 2012 17:47, Ingmar Brouns wrote: > As I noted that (null,null) is null, I thought why put (null,null) in an > array when that is the same as putting null in there. > However, when trying to unnest that array I got an error when using null > instead of the tuple. I experimented a bit, a

[GENERAL] The semantics of (NULL,NULL) vs NULL

2012-08-02 Thread Ingmar Brouns
Hi, I have a question. As I noted that (null,null) is null, I thought why put (null,null) in an array when that is the same as putting null in there. However, when trying to unnest that array I got an error when using null instead of the tuple. I experimented a bit, and read the documentation on