If digiKam crashes a lot on your machine running Ubuntu 14.04 or any of its derivatives, the most likely culprit is a bug in the SQLite database version 3.8.2 (see bug 329697). Fortunately, this problem is easy to fix: you need to install newer libsqlite3-0 and sqlite3 packages manually from the Utopic Unicorn repositories. To do this, download both packages (choose the i386 or amd64 version depending on your platform), then install them using the following commands (replace xxx with the appropriate architecture, i.e., i386 or amd64):
sudo dpkg -i libsqlite3-0_3.8.6-1_xxx.deb
sudo dpkg -i sqlite3_3.8.6-1_xxx.deb
Note that you need to install the libsqlite3-0_3.8.6-1_xxx.deb package first. That’s all there is to it.