til/postgres/pretty-print-data-sizes.md

Pretty Print Data Sizes

Use the pg_size_pretty() function to pretty print the sizes of data in PostgreSQL. Given a bigint, it will determine the most human-readable format with which to print the value:

> select pg_size_pretty(1234::bigint);
 pg_size_pretty
----------------
 1234 bytes

> select pg_size_pretty(123456::bigint);
 pg_size_pretty
----------------
 121 kB

> select pg_size_pretty(1234567899::bigint);
 pg_size_pretty
----------------
 1177 MB

> select pg_size_pretty(12345678999::bigint);
 pg_size_pretty
----------------
 11 GB

This function is particularly useful when used with the pg_database_size() and pg_relation_size() functions.

> select pg_size_pretty(pg_database_size('hr_hotels'));
 pg_size_pretty
----------------
 12 MB