What does the search index mean in Search Service Application?

Question

I'm completly new to Sharepoint so I appologize if my question is stupid.

I'm having problems in understanding how Sharepoint Search Service Application works. I've learned so far that it's a self-contained search unit that when configured offers enterprise search capabilities to a farm and that one of its main areas is the Query area, which stores the search index.

Ok, so what exactly is the search index? Is it a column? A primary key? How do you perform a search using the Search Service Application? How do you choose the index?

Thank you in advance.

Answer 1

Search Index is very similar to an index in a book. It's the place where all the keywords, metadata are stored during the Crawling process. Crawler analyze all the words in documents and put them into the Index. When you perform a search, query get executed against the Index.

Answer 2

To add to Joy Rathnayake,

Just imagine what would happen if a search result would have to read through every single file every time someone does a search. The system would simply stop completely.

The search index is a database table (Or tables, haven't looked at it from the inside), that contains a list of basic data of everything in your source (Which can be a fileshare, website, etc)

For performance reasons, resources are split between all of these functions. There's a crawling process that simply reads the files and records and fills the search index. There's a query process that speaks to the search index table.

Usually the crawling process causes such a load you're always better off splitting it from the web server because it locks up everything else.

For more information, best to read a good article on this: http://blogs.msdn.com/b/russmax/archive/2013/06/06/search-2013-search-architecture-part-1-intro.aspx