Suggest Sphinx index scheme

In a MySQL database I have documents of different type: some have text content, meta keys, descriptions, others have code, SKU number, size and brand name and so on. The problem is, I have to search something in all of these documents and then display a single page, where the results will be grouped by the document type, such as help page, blog post, item... It's not clear for me how to implement the Sphinx index: I want to have a single index to speed up queries, but since different docs have different structure - how can I group them? I was thinking about just concatenating them, but it just doe开发者_开发知识库sn't feel right.

Sphinx does not actually return documents, concatenated or not, it returns primary keys of the items or attributes you have indexed. Here, in this snippet from a sphinx.conf, the SQL here is used to build an index. When the index is subsequently searched, product.id will be returned whilst text2search will be searched.

sql_query = SELECT id, CONCAT_WS( ' ', field1, field2 ) as text2search FROM product

If your documents/products reside in the same database table, this is very straightforward. You are able to retrieve and recreate your data structure on the database side when given the primary key(s) to work with.

If you are indexing items of different types in one sphinx index when each type is mapped to a different table, it's a little more involved.