Re: database size changed after restoring using pg_restore

[John R Pierce <pierce@xxxxxxxxxxxx>]

On 11/8/2017 2:59 PM, Dylan Luong wrote:

Hi

I am upgrading some databases from a PostgreSQL 9.2 server to a new PostgreSQL 9.6 server.

I used pg_dump and pg_restore for the upgrade. 

.....

But when I listed the size of the database (postgres=# \l+) between the 9.2 and the upgraded 9.6, they were different.

on 9.2 it was 3776 MB
on 9.6 it was 1570 MB

I also did a few more databases using the same steps and they all appeared to be smaller. Is that normal?

yes.  a freshly restored database will be all contiguous with no embedded free tuples left over from operations.   databases that get updates (or inserts/deletes) tend to bloat.

-- 
john r pierce, recycling bits in santa cruz