All files that are stored in Content Services are stored in what is referred to as the repository. The repository is a logical entity that consists of three important parts:
- The physical content files that are uploaded, which are stored in the file system.
- The index files created when indexing the uploaded file so it is searchable, which are managed by an external Apache Solr server.
- The metadata/properties for the file, which are stored in a relational database management system (RDBMS).
When a file is uploaded to the repository it is stored on disk in a special directory structure that is based on the date and time of the upload. The file name is also changed to the UUID (Universally Unique Identifier) assigned to the file when it is added to the repository. The file’s metadata is stored in an RDBMS such as PostgreSQL. Indexes are also stored on the disk. When the file is added to the repository it is stored in a folder, and the folder has domain specific metadata, rules, and fine grained permissions. The top folder in the repository is called Company Home, although it will be referred to with the name repository in the Alfresco Share user interface.
When a file is uploaded to the repository it is always classified according to a so called content model. A content model is one of the first things that will be designed and implemented in a content management project. It customizes the repository to store information for a specific domain, such as healthcare, finance, manufacturing, legal etc. By classifying content (i.e. files and folders) end users can search and process content more effeciently.