In the SQL Developer group on OracleCommunity.net, both Chris and Chen complained about the new SQL Developer’s automatic code completion and how it could freeze the entire editor while waiting for the popup to appear.
I have experienced this behavior too. It is really frustrating when it happens. The solution, however, is really simple. In SQL Developer, go to Tools > Preferences > Code Insight and uncheck both “Enable Auto-Popup” check boxes as seen in the following screenshot:
Now, instead of letting it load automatically, you control when the context sensitive code completion insight popup appears. Simply press Ctrl+Space and voila.
By the way, Vadim Tropashko has a great article about getting most of code completion in SQL Developer.