Can some one tell me how much space is required for context index creation.Since it depends on table size please tell me in comparison with space occupied by table.
Example: if table takes 100MB then context index needs some 200MB etc..
However, if you are indexing plain text, and using the default options (in particular, not using the SUBSTRING_INDEX option) then your index size will be typically 35-45% of the original text size. So 100MB of text will require 35-45MB of index space.
If you're indexing word or PDF documents with embedded graphics, the overhead will be much lower.