Calculate the total size in bytes for a column

peterlandis · ‎08-09-2023

I wanted to calculate the total size in bytes for a given column for a table. I saw that you can use the bit_length function and did something like this giving you the total bits of the column but not sure if this is correct.

SELECT sum(bit_length(to_binary(content, 'UTF-8'))) as total_bites FROM mytable;

When I look at running the DESCRIBE, the table sizeInBytes is way less then the above. Is that because the size in table is actually compressed vs the bit_length is calculating without compression?

DESCRIBE DETAIL mytable;