Search functionality in SharePoint 2013 Preview includes several enhancements including custom content processing with the Content Enrichment web service, and a new framework for presenting search result types. There have been significant enhancements made to the keyword query language. Search is a scorching topic within SharePoint 2013, the following is a summary of some of the search enhancements.
Content Search Web Part
In many ways this can be considered as the next generation of the previous Content Query Web Part. The Content Search Web Part displays content that was crawled and added to the search index. We can use category pages when we want to collect content that meets certain criteria or parameters. To understand correctly, take the example of an intranet scenario, all company events are maintained in a list that is shared as a catalogue. A query is issued from the Content Search Web Part to return all items from the search indexes that are specified in the query.
User interface improvements
In SharePoint 2013, without having to open each search result, users can quickly identify useful results in many ways.
- Users can hover the pointer over a search result to preview the document content in the hover panel to the right of the result.
- Users can quickly distinguish search results based on document types. For example, for Microsoft Office documents, the application icon is displayed in front of the title of the search result. We can customize it to add more icons
- By default, certain types of related results are displayed in groups called result blocks. A result block contains a small subset of results that are related in a particular way. For example, results that are PowerPoint documents appear in a result block when the word presentation is one of the search terms.
- Search is personalized to each user. For example, results that the user previously clicked appear in query suggestions and are promoted in the result ranking, so that the user can find documents more quickly.
Site collection administrators and site owners can use display templates to customize the appearance of search results by using an HTML editor, and they can customize the behavior of search results by using JavaScript. They can specify display templates that determine how result types appear.
A search result, suggestion, or recommendation is more relevant when it better satisfies the intent of the person who issues the query. SharePoint Server 2013 improves relevance in areas such as cleanness of search results, phonology, and document parsing. We can discuss each one in detail.
New ranking models
SharePoint Server 2013 provides new ranking models for people search, intranet sites, and Internet sites. A ranking model determines and rank.
Content Analysis and user interaction
The search system determines the relevance of search results in part by how content is connected, how often an item appears in search results, and which search results people click. The new analytics component in SharePoint Server 2013 tracks and analyzes this information and uses it to continuously improve relevance.
Based on analytics information, site collection administrators and site owners can customize the user experience by adding Web Parts to display recommendations and popular items.
Query rules
Without any custom code, Search service administrators, site collection administrators, and site owners can help searches respond to the intent of users by creating query rules. In a query rule, you specify conditions and correlated actions. When a query meets the conditions in a query rule, the search system performs the specified actions to improve the relevance of the search results.
Result sources
In SharePoint Server 2010, scopes and federated locations provided ways to limit searches to a certain set of content or subset of search results. In SharePoint Server 2013, result sources replace scopes and federated locations. You create and use a result source to specify a location from which to get search results and to specify a protocol for getting those results.
Crawling Improvements
SharePoint Server 2013 includes many changes and improvements related to crawling content.
Continuous crawl
In SharePoint Server 2013, you can configure crawl schedules for SharePoint content sources so that crawls are performed continuously. Setting this option eliminates the need to schedule incremental crawls and automatically starts crawls as necessary to keep the search index fresh.
Host distribution rules removed
SharePoint Server 2013 does not use host distribution rules. Instead, Search service application administrators can determine whether the crawl database should be rebalanced by monitoring the Databases view in the crawl log.
Removing items from the search index
In SharePoint Server 2010, Search service application administrators could remove items from the search index by using Search Result Removal. In SharePoint Server 2013, you can remove items from the search index only by using the crawl logs.
Discovering Contents from unstructured content
We can configure the crawler to look for entities in unstructured content, such as in the body text or the title of a document. These entities can be words or phrases, such as product names. To specify which entities to look for in the content, you can create and deploy your own dictionaries. For companies, you can use the pre-populated company extraction dictionary that SharePoint Server 2013 provides.
Improved search schema
By defining crawled properties, managed properties, and the mappings among them, the search schema determines how the properties of crawled content are saved to the search index. Crawled properties and how these are mapped to managed properties define how to transform crawled content into managed properties. The search index stores the contents of the managed properties. The attributes of the managed properties determine the search index structure. SharePoint Server 2013 introduces new attributes that you can apply to managed properties, such as sortable and refinable. The sortable attribute reduces the time that is required to return large search result sets by sorting results before they are returned. The refinable attribute enables you to create a refiner based on a particular managed property.
Search health reports
SharePoint Server 2013 provides many query health reports and crawl health reports.
For a better search experience please consider the following points while you design the farm:
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Small Search farm with dedicated Search
The following farm architecture diagram illustrates only the search components and can serve as a dedicated search farm for one or more SharePoint farms. Dedicated search farms do not include Web servers.
![SharePoint-Server-2013-1.gif]()
For more details please read the following MSDN article http://technet.microsoft.com/en-us/library/jj219669(v=office.15)