We had two ADFS(Active Directory Federated Service) users not showing up in site collection although their user profile was being pulled properly from AD. We tried full synch, but it never worked. What worked for us were below steps in that order.
stsadm -o sync -listolddatabases 0
stsadm -o sync -deleteolddatabases 0
The listolddatabases <n>option will list the databases that have not been successfully synchronized the last <n> days, and the deleteolddatabases <n>option will delete the synchronization information from the databases that are not successfully synchronized the last <n> days. deleteolddatabases option will not delete the content databases.
stsadm –o sync –synctiming M:5
stsadm –o sync –sweeptiming M:5
The above two commands will set the Profile Sync job and Quick Profile Sync job to run every 5 minutes.
The two users who had this problem had few stale entries in site collection, which we deleted before running the above command