...
- configuration
- edbplus (note: don't delete if connecting to DB2 EnterpriseDB databases)
- features
- img
- instantclient (note: don't delete if connecting to Oracle databases)
- jre (note: see Caveat #2)
- licenses
- p2
- plugins (note: there is also a “plugins” subdirectory in /repl directory which is needed for REPL)
...
If you are connecting to Oracle databases or DB2 Postgres EnterpriseDB (EDB) databases, you will need item #5 and #6 above (Oracle instant client and EDB client).
Caveat #2: Bring your own Java
Your Java needs to be Java 7 or Java 8.
To use your own Java instead of the Datical-provided one (in the jre directory), you can point your JAVA_HOME environment variable to your Java 7 or 8 path.