<< Click to Display Table of Contents >> Navigation:  General Functions > Performing Local Backup > How Data is Transferred

The SFT client will transfer data from the MIE to your local database on the schedule you set when you define the SFT job on the MIE.  Each time the transfer is started, the SFT client first pulls the schema meta-data for your local table from the MIE.  It compares your current database structure to the structure definition and, if they differ, your local database will be automatically adjusted to match the MIE's structure definition.  If you store your data in Access, your current Access database will first be backed up to the same directory.

Then, once transfer starts, the MIE will progress one table at a time.  It requests all records for the currently processing table that have a date last updated equal to or later than the date of last successful transfer.  Depending on when, during the day, the last successful transfer occurred, this may cause some overlap (records to be sent that were already sent).  This is by design to ensure no records are missed.  

Once all recently updated records have been pulled down, the SFT client then requests a full list of all known records (it requests a list of key values only).  It uses this list to compare to the records in your local database.  If you have a record in your local database that is not in the list, it means the record was deleted from the MIE and the SFT client will delete it from your local database.  Note that this second step - the step of deleting records from the local database that no longer exist on the MIE - occurs for most tables, but not all.  Some tables are set to skip this step, allowing the data in the local database to continue to grow over time.  Such tables tend to hold historical records, such as archive and/or offline tables.

When the operation is complete, the records in your local database should match what is on the MIE (with the exception of any changes that happened while the transfer was in progress).