Search notes:

/var/lib/dpkg

/var/lib/dpkg contains the dpgk database.

The dpkg database can be queried with dpkg-query.

Files and directories I've found in /var/lib/dpkg include:

`alternatives/`
`available`
`cmethopt`
`diversions`
`diversions-old`
`info/`
`lock`
`lock-frontend`
`parts/`
`statoverride`
`statoverride-old`
`status`
`status-old`
`triggers/`
`updates/`

See also

dpkg and its --admindir options which alows to use another directory.

/var/lib