I hope to know the ideal size of related work section in a regular article (regardless of the page limitations determined by the journal/conference committee). Should it discuss only the current state-of-the-art in X? research?
Dear Hussein Al-haj Ahmad, related work is normally cited in the Introduction of an article. This should not exceed 1 page, but full credit should be given to the work of the pioneers in the field. Closely related current work should also be cited in full. In order to keep the number of references limited, you could cite e.g. suitable review articles.
I would agree with Professor Edelmann's advice above. However, I think it depends on the norms in your field, the norms for the type of article your target journal publishes, the length of the article, and the type of article you are writing. My field of Social Work is completely different from yours, but my literature review would vary in length depending on the above variables. If in doubt, I would look at your target journal and see what the practice is there.
It has a lot to do with the type of journal but should not necessarily exceed a page. Related studies should focus on very recent works and not from srudies from the inception of the topic in question