Is there a better way to calculate the median (not average)

Question

Suppose I have the following table definition:

CREATE TABLE x (i serial primary key, value integer not null);

I want to calculate the MEDIAN o

Answer 1

Use the Below function for Finding nth percentile

CREATE or REPLACE FUNCTION nth_percentil(anyarray, int)
    RETURNS 
        anyelement as 
    $$
        SELECT $1[$2/100.0 * array_upper($1,1) + 1] ;
    $$ 
LANGUAGE SQL IMMUTABLE STRICT;

In Your case it's 50th Percentile.

Use the Below Query to get the Median

SELECT nth_percentil(ARRAY (SELECT Field_name FROM table_name ORDER BY 1),50)

This will give you 50th percentile which is the median basically.

Hope this is helpful.