Mastering PostgreSQL 9.6

Extracting subsets of data

Up to now, you have seen how to dump an entire database. However, this is not what you might wish for. In many cases, you might just want to extract a subset of tables or schemas. pg_dump can do that and provides a number of switches:

• -a: It dumps only the data and does not dump the data structure
• -s: It dumps only the data structure but skips the data
• -n: It dumps only a certain schema
• -N: It dumps everything but excludes certain schemas
• -t: It dumps only certain tables
• -T: It dumps everything but certain tables (this can make sense if you want to exclude logging tables and so on)

Partial dumps can be very useful to speed up things considerably.