\set ncolumns 1000
\set nrows 400

\o /dev/null
drop table if exists normal, missing, dropped;

-- normal case, all attrs exist in the tuples
select 'create table normal (' || string_agg('c'|| x::text || ' int',',') || ');' from generate_Series(1,:ncolumns) x;
\gexec

select 'insert into normal select ' || left(repeat('1,',:ncolumns),-1) || ' from generate_Series(1,' || :nrows || ') x;';
\gexec

-- missing case. Table has all attrs missing
create table missing();
INSERT INTO missing SELECT FROM generate_series(1,:nrows);
select 'alter table missing ' || string_agg('add column c'||x::text || ' int default 1',',') || ';' from generate_Series(1,:ncolumns) x;
\gexec

-- first column dropped
select 'create table dropped (' || string_agg('c'|| x::text || ' int',',') || ');' from generate_Series(0,:ncolumns) x;
\gexec
select 'insert into dropped select ' || left(repeat('1,',:ncolumns + 1),-1) || ' from generate_Series(1,' || :nrows || ') x;';
\gexec
alter table dropped drop column c0;

\o

select relname,pg_relation_Size(oid) table_size_bytes from pg_class where relname in('normal','missing','dropped');