Summary
Warning! The maximum key length is 900 bytes. The index 'IX_xxxx' has maximum length of 1232 bytes. For some combination of large values, the insert/update operation will fail.
Synopsis
Discussion
You may experience the following error in the importer log:
Warning! The maximum key length is 900 bytes. The index 'IX_xxxx' has maximum length of 1232 bytes. For some combination of large values, the insert/update operation will fail.
Example:
2015-12-08 02:00:51,681 [WARN ] Warning! The maximum key length is 900 bytes. The index 'IX_TempVdiUser' has maximum length of 1232 bytes. For some combination of large values, the insert/update operation will fail.
2015-12-08 02:00:51,681 [WARN ] Warning! The maximum key length is 900 bytes. The index 'IX_TempVdiEndPointAccess' has maximum length of 1192 bytes. For some combination of large values, the insert/update operation will fail.
Workaround
The warnings you are seeing are actually due to the difference between the field size in the data source and the index table.
If you were receiving errors after this warning then it would be something that would require further investigation. As this is a warning it isn't stopping the import operation, as such the compliance import should be successful.