The Flat File Active Sync adapter can track the timestamp of a flat file. In addition, the adapter can archive the last file processed and then compare it to the most recent version. Identity Manager will then act on the accounts that are different in the two files.
If these features are enabled, the first time Identity Manager polls the source flat file, the system copies the file and places it in the same directory. The copied (archived) file is named FFAS_timestamp.FFAS, with the timestamp indicating the last time the original file was changed. The format of the timestamp is determined by the operating system on which the source file resides.
On each subsequent poll, Identity Manager compares the timestamp on the original file with the most recent timestamp. If the new timestamp value is the same as the previous value, then the file has not changed, and no further processing is performed until the next poll. If the timestamp values are different, Identity Manager checks for the presence of the FFAS file. If the file does not exist, Identity Manager processes the updated source file as if it were a new file.
If the timestamps are different and the archived FFAS file exists, Identity Manager compares the source file with the archived file. The comparison will filter any users that have not changed. If a user has changed, then it will be sent through the adapter in the normal manner, and the configured process, correlation and delete rules determine what to do with the user.
To facilitate these rules, the adapter will add an additional attribute to indicate the situation discovered by the difference mechanism. If any users exist only in the newly updated source file, the user record will have an additional attribute diffAction which will have the value of create. If any entries were updated in the source file, the attribute diffAction will be added and the value set to update. If any users were deleted then diffAction will be delete.
After the comparison of the two files is complete and all account processing has taken place, Identity Manager deletes the original FFAS file and copies the current source file to a new FFAS file. The timestamp on this file will be different than the previous FFAS file.