MySQL头痛，我应该或不应该？

Question

I have a classifieds website. I am using SOLR for indexing and storing data. Then I also have a MySQL db with some more information about the classified which I dont store or index.

Now, I have a pretty normalized db with 4 tables.

Whenever ads are searched on the website, SOLR does the searching and returns an array of ID_numbers which will then be used to query mysql. So solr returns id:s, which are then used to get all ads from the mysql db with THOSE id:s.

Now, all the JOIN and relations between my tables gives me a headache.

What except for maintanance-ease do I get for having a normalized db?

I could you know, store all info into one table with some 50 columns.

So instead of this for finding one ad and displaying it:

SELECT 
  category_option.option_name,
  option_values.value 
FROM classified, category_option, option_values 
WHERE classified.classified_id=?id 
AND classified.cat_id=category_options.cat_id 
AND option_values.option_id=category_options.option_id

I could use this:

SELECT * FROM table_name WHERE classified_id = $classified_id

Isn't the last one actually faster? Or does a normalized db permform faster?

Thanks

Answer 1

I would advise against denormalizing in your situation. You'll get better with joins as you use them more and they start to become clearer in your head, and maintenance ease is a good benefit for the future.

Here's a pretty good link about normalization (and denormalization). Here's a question about denormalization. One answer suggests creating a view using joins to get the data you need, and using that like your SELECT * FROM table_name WHERE classified_id = $classified_id query. A normalized DB will likely be slower, but it's unlikely you'll want to denormalize for that reason. I hope this provides some help.