Downgrade PostgreSQL 10 syntax for backwards compatibility

downgrade_psql_syntax.rb

#!/usr/bin/env ruby
# typed: ignore
# Makes PostgreSQL > 9 syntax compatible with < 10

sql = File.open('./db/structure.sql', 'r+')
inside_create_sequence = false
out = ''

sql.each_line do |line|
  if inside_create_sequence && line.strip == 'AS integer'
    next
  elsif line.strip == 'SET xmloption = content;'
    next
  elsif line.strip == 'SET default_table_access_method = heap;'
    out += "SET default_with_oids = false;\n"
  elsif line.include?('EXECUTE FUNCTION')
    out += line.gsub('EXECUTE FUNCTION', 'EXECUTE PROCEDURE')
  else
    out += line
  end

  inside_create_sequence = line.start_with?('CREATE SEQUENCE')
end

File.truncate('./db/structure.sql', 0)
sql.seek(0, IO::SEEK_SET)
sql.write(out)