i think it is not a matter whether is it more effective or not. it depends on what is the source you are searching for. if you dont really know exact what you are searching for, search engine is a better choice. however, if im precise on specific part of the information i need, database is the choice.

however, through my experience, database sometimes is not very up-to-date. therefore, i'll still stick to search engine even though i know what im looking for.

in my diploma research, i think database is a better resource. certain research do not require frequent updates and very rich source is congregated in the database.