Subject | RE: [firebird-support] searching a varchar(100) column |
---|---|
Author | Alan McDonald |
Post date | 2005-04-29T23:11:41Z |
> The problem is that "like" cannot use an index, so everything becomes atoo much disk space/DB pages used for the index. you're always better off
> table space scan.
>
> I don't know how this will work - It is similar to a couple of
> suggestions I have already seen in response to your question.
>
> 1. make the primary key of your book table something other than the
> title. ISBN is a good choice. I'll just call this <<primary key>>
>
> 2. create a separate keyword to book relationship table, that is
> structured as keyword, <<primary key>>. I would be tempted to make its
> primary key both of its columns.
here with a surrogate integer key as PK. Comments?
>now all we need is a UDF/SP/methodology to do the parsing.
> 3. select b.title, <<primary key>>, count(*)
> from kwd_book_rel a,
> books b
> where a.keyword in (.....)
> and b.<<primary key>> = a.<<primary key>>
> group by b.title
> order by 2 desc
>
> will return a list of all titles containing the keywords, in order of
> most to least hits.
>
> The list can be pared down more with a little effort, but that's the
> gist.
Maybe client side parsing with insert queries. duplicates could be ignored
under this schema and removed during a housekeeping procedure with little
penalty
Alan