CREATE OR REPLACE FUNCTION parse_int(val) AS (
  regexp_extract('decimal(12,3)', '[0-9]+')::INTEGER
);

# DECIMAL(p, s):
CREATE OR REPLACE FUNCTION d2w(p) AS (
  if( p <=  4, 16,
  if( p <=  9, 32,
  if( p <= 18, 64,
              128) ))
);

CREATE OR REPLACE FUNCTION nominal_size_in_bits(val) AS (
  CASE typeof(val)
    WHEN 'TINYINT' THEN 8
    WHEN 'SMALLINT' THEN 16
    WHEN 'INTEGER' THEN 32
    WHEN 'BIGINT' THEN 64
    WHEN 'HUGEINT' THEN 128

    WHEN 'UTINYINT' THEN 8
    WHEN 'USMALLINT' THEN 16
    WHEN 'UINTEGER' THEN 32
    WHEN 'UBIGINT' THEN 64
    WHEN 'UHUGEINT' THEN 128

    WHEN 'JSON' THEN 8 * length(val::JSON::VARCHAR)
    WHEN 'UUID' THEN 128

    WHEN 'FLOAT' THEN 32
    WHEN 'DOUBLE' THEN 64
    WHEN 'BOOLEAN' THEN 8
    WHEN 'BIT' THEN (CEIL(LENGTH(val::VARCHAR) / 8.0) * 8)::INTEGER
    WHEN 'BLOB' THEN octet_length(val::BLOB) * 8
    ELSE CASE
           WHEN typeof(val) LIKE 'DECIMAL%'
           THEN d2w( regexp_extract(typeof(val), '[0-9]+')::INTEGER )
           WHEN typeof(val) LIKE 'VARCHAR%'
           THEN 8 * octet_length(encode(val::VARCHAR))
           ELSE NULL
           END
    END
);

# Example:

select nominal_size_in_bits('1'::BIT) as "1::BIT",
       nominal_size_in_bits(bitstring('1',7)) as "0000001",
       nominal_size_in_bits(9.4) as "9.4",
       nominal_size_in_bits('👨') as "glyph";