Efficient Filtering / Searching

问题:

We have a hosted application that manages pages of content. Each page can have a number of customized fields, and some standard fields (timestamp, user name, user email, etc).

With potentially hundreds of different sites using the system -- what is an efficient way to handle filtering/searching? Picture a grid view that you want to narrow down. You can filter on specific fields (userid, date) or you can enter a full-text search.

For example, "all pages started by userid 10" would be a pretty quick query against a MySQL database. But things like "all pages started by a user whose userid is 10 and matches [some search query]" would suck against the database, so it's suited for a search engine like Lucene.

Basically I'm wondering how other large sites do this sort of thing. Do they utilize a search engine 100% for all types of filtering? Do they mix database queries with a search engine?

If we use only a search engine, there's a problem with the delay time it takes for a new/updated object to appear in the search index. That is, I've read that it's not smart to update the index immediately, and to do it in batches instead. Even if this means every 5 minutes, users will get confused when their recently added page isn't immediately listed when they view a simple page listing (say a search query of "category:5").

We are using MySQL and have been looking closely at Lucene for searching. Is there some other technology I don't know about?

My thought is to offer a simple filtering page which uses MySQL to filter on basic fields. Then offer a separate fulltext search page that would present results similar to Google. Is this the only way?

回答1:

Solr or grassyknoll both provide slightly more abstract interfaces to Lucene.

That said: Yes. If you are a primarily content driven site, providing fulltext searching over your data, there is something in play beyond LIKE. While MySql's FULLTEXT indexies aren't perfect, it might be an acceptable placeholder in the interim.

Assuming you do create a Lucene index, linking Lucene Documents to your relational objects is pretty straightforward, simply add a stored property to the document at index time (this property can be a url, ID, GUID etc.) Then, searching becomes a 2 phase system: 1) Issue query to Lucene indexies (Display simple results like title) 2) Get more detailed information about the object from your relational stores by its key

Since instantiation of Documents is relatively expensive in Lucene, you only want to store fields searched in the Lucene index, as opposed to complete clones of your relational objects.

回答2:

Don't write-off MySQL so readily!

Implement it using the database e.g. a select with a 'like' in the where-clause or whatever.

Profile it, add indexes if necessary. Roll out a beta, so you get real numbers from user's actual data patterns - not all columns might be equally asked after, etc.

If the performance does suck, then thats when you consider other options. You can consider tuning your SQL, your database, the machine the database is running on, and finally using another technology stack...

回答3:

In case you want to use MySQL or PostgreSQL, a open source solution that works great with it is Sphinx: http://www.sphinxsearch.com/

We are having the same problem and considering Sphinx and Lucene as possible solutions.