selecting and Inserting data from two different servers
If the duration is related to data volume, you should consider syncing only the modified data:


put an IsDirty flag on each student record
sync (delete + insert or simple updates) data only for records where IsDirty = 1


This should work decently if a fairly small amount of records change between the sync. 

Another option is to try to sync data directly between MySql and PSql as indicated here. Also, take a look upon dblink.