The full installation for EtaPRO Server as available from the EtaPRO Support site includes an installation package for Microsoft SQL Server Express.
For EtaPRO 10.2, it is recommended to only use Microsoft SQL Server Express with systems that communicate with an external historian (PI,OPC) and not EPArchive due to database size limitations set by Microsoft for SQL Express. Customers with EtaPRO 10.2 systems having EPArchive and/or Advanced Pattern Recognition enabled should attach EtaPRO databases to a fully licensed SQL Server edition.
For EtaPRO 10.3, a new EPArchive File System storage method was introduced, which can be used in place of or in addition to Microsoft SQL Server. For more information on the EPArchive File System, please read these articles:
SQL Express Database Size Limits
Microsoft SQL Server 2005 Express: 4GB
Microsoft SQL Server 2008 Express: 4GB
Microsoft SQL Server 2008 R2 Express: 10GB
Microsoft SQL Server 2012 Express: 10GB
Microsoft SQL Server 2014 Express: 10GB
Additional features and limitations of SQL Server Express can be viewed here: https://msdn.microsoft.com/en-us/library/cc645993%28v=sql.105%29.aspx
If your EtaPRO system uses SQL Express and the database file size is getting close to the 10 GB limitation, you can always upgrade to a Full Edition ("Full" SQL licenses are not available from GP Strategies Corporation). If you do not wish to upgrade to a Full Edition of SQL Server, and your database file size is getting close to the 10GB limitation, please contact EtaPRO Support to discuss conversion to the EPArchive File System.
If your EPArchive or APR database has already reached the 10 GB limitation, contact EtaPRO Support immediately as new data can not be written to the database.