Jason Aten <jaten(at)CS(dot)UCLA(dot)EDU> writes:
> testdb=# select f[2][1:5] from arr; (ask row back, get two!)
This is implicitly an array slice operation, so it's the same as
select f[1:2][1:5] from arr;
If you want just the one row you need to write
select f[2:2][1:5] from arr;
The behavior of the cases with too few subscripts does seem pretty
unhelpful --- seems like either raising an error or returning a
slice would make more sense than returning NULL. But that's how
the code is set up at the moment.
regards, tom lane