A role with SELECT on every table and access to every schema runs pg_dump against one database. The -F or --format option picks the output: plain SQL script (-F p, the default, restored with psql), custom (-F c), directory (-F d, which takes parallel jobs with -j) or tar (-F t). Compression is set with -Z or --compress and takes gzip, lz4 or zstd; custom and directory are compressed by default and tar cannot be compressed. pg_dump covers one database at a time, so a whole cluster including roles, tablespaces and database level settings goes out through pg_dumpall. Where the connecting user lacks the read privileges, --role=rolename issues SET ROLE after connecting.
What it holds
Application tables and their rows, schemas, views, sequences and functions for whatever the business runs on Postgres.
Find the size
Postgres has no console, so read the figure from the server. select pg_size_pretty(pg_database_size('dbname')) returns the disk space that database uses, and pg_total_relation_size on a table returns that table plus its indexes and TOAST data. Calling pg_database_size needs CONNECT on the database or the pg_read_all_stats role.
What to enter on the form
PostgreSQL in GB, and the year your company started using it. Seller form