Here is a rather interesting video from Martin Kleppmann where he talks about dealing with concurrent changes to data. While the title may sound theoretical to some, it is a topic that probably every developer has come across. And here is also the link to the paper with the algorithm presented. If you are interested in an implementation, check this Github project.
Sometimes people wonder why Oracle DB (both 10g and 11g) will not start after installation on Linux/Unix. In many cases the simple reason is the content of /etc/oratab. For each database it contains a line in the format $ORACLE_SID:$ORACLE_HOME:START_DB_FLAG:The last column is set to “N” by default. Just change it to “Y” and run $ORACLE_HOME/bin/dbstart again. Your database should come up now.