mayeulk's solution could work fine when the number of columns is less than 2048. Once the number reaches 2048, you cannot read out the content of table. I tried (on PG17.2) and the result is:

postgres=# select col1 from large_table;
col1
------

(1 row)

Yes, there does be a tuple in this table and the result shows you one row is retrieved. But you got nothing. Definitely some limitation exists somewhere.

Steven