An Encyclopedia volume consists of files such as BIRT designs, documents, and information objects. iHub creates a default Encyclopedia volume during installation. The installation process names the default Encyclopedia volume the same as the machine name, as shown in Figure 2‑1.

The default Encyclopedia volume directory is AC_DATA_HOME/encyc. By default, AC_DATA_HOME on a Windows system is Actuate\iHub\data. On a Linux system, AC_DATA_HOME is AcServer/data.

In an out-of-the-box (OOTB) installation, iHub stores Encyclopedia volume metadata, such as information about users, roles, groups, and job schedules, in the PostgreSQL database installed with iHub. The PostgreSQL database resides in AC_DATA_HOME/encyc. iHub stores configuration metadata in the database separately from data such as designs, documents, information objects, and other iHub data objects, which are stored in the file system. Files containing data have the .dat file-name extension in the file system, regardless of their Actuate file type. By default, the .dat files reside in AC_DATA_HOME/encyc/file.