Sharepoint 2010. Search

I am not very familiar with sharepoint so probably this can be builtin function or something....

I have 200 sites and i need really fast search inside documents and pages.

What is the best way to perform search and cache some items?

• I need also to show sear开发者_StackOverflow社区ch items while customer types text inside text box. How can i perform search for that purpose(Ajax+WCF. question about sharepoint API).

This is no simple task with pitfalls you should be aware of:

• Find-on-type against the search index could lead to a overload of the system with a bottle neck to the SQL server (High traffic between front end and back end).
• Caching is difficult since for a search you probably want to cache per user to avoid security issues.

Use paging to avoid returning the whole set:

using Microsoft.Office.Server.Search.Query;
// ...
Query query = new FullTextSqlQuery(site);
query.StartRow = x;
query.RowLmit = 10;

Check out our product MatchPoint. MatchPoint is a application framework for SharePoint that includes a set of web parts providing the functionality you require for this task.

Take a look at this:
Getting started with enterprise search in SharePoint 2010 Products (white paper)