dbsize & pg_dump - Mailing list pgsql-admin

Good afternoon,

Probably an easy question but why are the file sizes differ so much between these two tools?

For example: 

A backup using pg_dump of our largest DB creates a file 384MB in size

Using the following SQL code utilizing dbsize I get the following:

FIX1=# SELECT D1.pg_size_pretty AS "FIX1_DB_SIZE"

FIX1-# FROM (SELECT pg_size_pretty(database_size('FIX1'))) D1;

 FIX1_DB_SIZE

--------------

 3832 MB

(1 row)

Is it safe to assume that pg_dump does a compression of the data?

Thanks

Tim