Vi is an everyday tool for an Oracle DBA. Commands are many, here's a PDF cheatsheet if you want to become an expert: http://www.math.ntu.edu.tw/~wwang/mtxcomp2010/cssd2011/download/vi_cheat%20sheet.pdf
At the end you get handle yourself with the same commands. I specifically use:
/ -> Lookahead
The inverted table format can deliver fast and flexible query capabilities, but is not widely used. ADABAS is probably the most successful implementation, but how often do you see that nowadays? Following is a description of how to implement inverted structures within a relational database. All code run on Oracle Database 12c, release 18.104.22.168.
There are three restrictions on indexing and partitioning: a unique index cannot be local non-prefixed; a global non-prefixed index is not possible; a bitmap index cannot be global. Why these limitations? I suspect that they are there to prevent us from doing something idiotic.