On a Debian 7 server, apt-get was offering me to upgrate the following 2 packages: postgresql-9.1 and postgresql-client-9.1. Since I didn't want to restart the database server, I decided only to upgrade the client and ran:
sudo apt-get install --only-upgrade postgresql-client-9.1
But this resulted in postgresql-9.1 being removed. I know that postgresql-9.1 depends on postgresql-client-9.1, but why would upgrading postgresql-client remove postgresql?
The apt-get upgrade
output looks fine:
~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
postgresql-9.1 postgresql-client-9.1
2 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/4,307 kB of archives.
After this operation, 432 kB of additional disk space will be used.
Do you want to continue [Y/n]?
But not when trying to upgrade only the client:
~$ sudo apt-get install --only-upgrade postgresql-client-9.1
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
postgresql-doc-9.1
The following packages will be REMOVED:
postgresql postgresql-9.1
The following packages will be upgraded:
postgresql-client-9.1
1 upgraded, 0 newly installed, 2 to remove and 0 not upgraded.
Need to get 0 B/996 kB of archives.
After this operation, 16.7 MB disk space will be freed.
Do you want to continue [Y/n]?