SQL is slow. That is why for quick operation you should use AmiBroker native database that is hundreds of times faster than SQL. In fact any external source is slower than native database.
The easy way to speed it up is to:
a) perform ONE scan to copy data from your SQL to AmIBroker native database
b) change Data source to “(local database)” in File->Database Settings
c) subsequent scans won’t use any external plugin and will be a whole lot faster than SQL and Norgate
There is one hint more: make sure that you have more than 3000 (number of symbols in your database) entered in Tools->Preferences, “Data” tab, “In-memory cache” field. This decides how many symbols are kept in RAM. RAM is order(s) of magnitude faster than any disk storage.