rpc.ttdbserverd is the RPC-based ToolTalk database server. It creates and manages database files kept in TT_DB directories. See ttdbserverd(1M).
The problem is usually caused by corrupted entries in some TT_DB directory. The solution is therefore to kill the running rpc.ttdbserverd, and to completely remove all local TT_DB directories.
rpc.ttdbserverd will be restarted from inetd when it is needed again. And it will rebuild the TT_DB directories automatically.
By default these TT_DB directories are created in the top directory of every filesystem, however one can use /etc/tt/partition_map to tell ttdbserverd where to put them. See partition_map(4) for more details.
A second possible cause is running out of filedescriptors, which can be fixed by upping the soft limit on the number of filedescriptors rpc.ttdbserverd starts with.