Difference in behaviour of Array with psql: multidimensional arrays must have array expressions with matching dimensions

[jon-chuang]

Describe the bug

psql

> select ARRAY[ARRAY[1], ARRAY[2, 3]];
ERROR:  multidimensional arrays must have array expressions with matching dimensions

risingwave

> select ARRAY[ARRAY[1], ARRAY[2, 3]];
    array    
-------------
 {{1},{2,3}}
(1 row)

To Reproduce

as above

Expected behavior

Should we be same as psql? Some users may have some nested list data without matching dim assumption. However, in this case, could they use jsonb as opposed to array?

We need the behaviour to be consistent at least for the purpose of implementing array_upper.

Additional context

Related: #8201
No response

[jon-chuang]

@xiangjinwu has suggested that we do not follow a C-type fixed dim semantic as psql does, but always allow a dynamic length.

We should figure out what our multi-dim array functions should do if we implement them. (e.g. array_ndims, array_dims, array_upper, array_lower)

Note that array_upper, array_lower have little meaning in our case, as array_lower == 1 and array_upper == array_length, since we currently do not support shifting the indexes (e.g. '[3:7]={1,1,1,1,1}'::integer[]).

[jon-chuang]

Note that jsonb can handle non-matching dims (as well as arrays with any type e.g. Any::[] )

select '[[1], [2, 3]]'::jsonb;
     jsonb     
---------------
 [[1], [2, 3]]
(1 row)

[xxchan]

#3811

[xxchan]

close as duplicate