Re: [HACKERS] "CANNOT EXTEND" -

> Is this from vacuum or pg_dump?

I'm not sure about the original message. In my case, I got 
NOTICE:  Can't truncate multi-segments relation tbl_mail_archive

while doing vacuum on a multi-segment relation.

However I didn't get:

ERROR:  Tuple is too big: size 10024

I'm not sure if I was just lucky.

> I'm just wondering if vacuum cannot cope with a table that is >1Gb
> (hence in two segments), and when cleaned down, is <1Gb (one segment).

I don't think vacuum is currently usable for a segmented relation.

> Saying that, why is it saying the tuple is too big? What is creating
> that tuple?

Seems that comes from RelationPutHeapTupleAtEnd(). It's saying
requested tuple length is too big to fit into a page.  (10024 is
apparently bigger than 8192) Someting very weird is going on...
---
Tatsuo Ishii