Usage of Search Feature in Alfresco Development
The Search functionality is one of the important facets for an Open Source CMS, and as you know, Alfresco uses most two powerful search engines LUCENE and Apache SOLR, Which provides high-performance, full-featured text search engine. It is very helpful tips for alfresco development. In previous version of Alfresco comes with only lucene search engine, but in latest version of Alfresco 4.x alfresco introduce with SOLR engine. Now Alfresco provides single text search feature.
Solr contains two cores in alfresco one is Workspace and archive.  
Workspace Store: searching all live content stored at alfresco/alf_data/contentstore. Archive Store: searching content that has been marked as deleted alfresco/alf_data/contentstore.
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Performing a search in Alfresco is easy. Simply type one or more search terms into the search box, and press the Enter key or click on the search icon
as shown in the below
You can use Google-style query syntax to search the content stored in the Alfresco repository. You can also use the advanced search form to create composite search criteria to search content, expand the advanced search form to comprise your custom content types and custom properties.
Source: Alfresco CMS Development