For anyone who uses the CommCare Data Export Tool:
A bug was identified in all versions between 0.13.0 and 0.18.0 that has the following impact:
Condition under which the bug manifests
Any export to a SQL database that fails part way or is cancelled before completion and then restarted without specifying the '--since' or '--start-over' command line parameters.
Consequence
Under the above conditions the export tool will not continue the export from where it left off but will instead skip ahead which could potentially leave some data unexported.
Fix
Upgrade to version 0.18.1 and run the export with the '--start-over' command line parameter to re-export all data.
Sincere apologies for any inconvenience.