Though we are not DB specialist, in our opinion, 1> you should extract the main text from the content using any html extraction library. 2> Store the extracted content in main field, on which you are searching. 3> Store the whole value with HTML Tags i.e.
<b>This</b> is <i>my text</i>
in the second field. Because if you have to render the HTML latter, then you will not have any extra burden of programming. You can simply look up in the main field with the search and then return the required html segment as it is.
Thanks