How to get the byte size of resultset in an SQL query?

Solution 1:

select sum(row_size) 
from (
  select 
    char_length(column1)+
    char_length(column2)+
    char_length(column3)+
    char_length(column4) ... <-- repeat for all columns
  as row_size 
  from your_table
) as tbl1;

char_length for enum, set might not accurate, please take note

Solution 2:

To build on Angelin's solution, if your data contains nulls, you'll want to add IFNULL to each column:

select sum(
    ifnull(char_length(column1), 0) +
    ifnull(char_length(column2), 0) +
    ifnull(char_length(column3), 0) +
    ifnull(char_length(column4), 0) ... <-- repeat for all columns
)
from your_table

Solution 3:

simplify :

select sum(char_length(column1)+
    char_length(column2)+
    char_length(column3)+
    char_length(column4) ... )<-- repeat for all columns
   from your_table

You need to add IFNULL() to each column as @futilerebel has mentioned