>I had a hard time to log onto U.T
>because an error has occurred to the internet service provider of mine.
>It's too late but I wanna ask you some more questions if you don't mind.
>If I understand you correctly,
>Do you mean that a record in a target table can have more than one
>corresponding record in the child table which contains Keywords?
>For instance,
>If the kewords of the current record is "black","color","paint","red"
>Should I make three corresponding records in child keyword table
>each contains one of the keywords and target Id?
>If it's true, is there any possiblity that the child table's gonna have too many records?
>Is it still fast enough when the number of records gets over 100,000?

After reading your original question, it seems what you need is a tool like PHDBase. This is what I use for the Universal Thread. As you can see, the result is immediate.

And other systems, I also use it on non memo field, like when searching for a specific chain in a telephone number, etc.

But, the technique Larry gave you is also good. It's up to you to decide, depending on the size of meta data you will create and all the work to manage it, to use a technique like this or to you a 3rd party tool.