Re: How are NULLS stored on disk for PG 7.4?

> On Wed, 14 Jan 2004, Yannick Warnier wrote:
>
>> Le mar 13/01/2004 à 00:43, Bruce Momjian a écrit :
>> > Arnold Mavromatis wrote:
>> > > Hi
>> > >
>> > > How are column files in a table that have been assigned null stored
>> on disk
>> > > in Postgresql 7.4?
>> >
>> > Each row has a bitmap showing all the NULL values on that row.
>>
>> Is it the same for PG 7.3?
>
> Yes, Postgresql has done this for quite some time.
>
My understanding is that Oracle has a field showing the size of the column
prior to each column. A column size of of zero means that the column is
null.

I assume that this is why Oracle is unable to make a distinction between a
null and a zero length string but that PostgreSQL can?

Vincent