architecture. content store vs content manager

by when the user runs the report,

1.The request is passed to the Web Server and gateways (CGI, ISAPI). The Cognos Gateway applies encryption to the information received, adds necessary environment variables and authentication.

2.The request will then be transferred to the Cognos BI Server Or application server. The BI Server will include the dispatcher and content Manager. The dispatcher used to handle the queries received from Gateways.

3.This request will now be passed to Content store. It will get all the metadata information and will be passed back to the user browser.

Content store is a relational database and much of the information is stored as binary large object (BLOB) fields

Content manager uses JDBC to access content store
Content Manager, stores information in the content store RDBMS.
Content Manager writes to the content store using proper relational transactions.
The content store is a relational database that contains data that IBM Cognos 8 needs to operate, such as report specifications, published models, and the packages that contain them; connection information for data sources; information about the external namespace, and the Cognos namespace itself; and information about scheduling and bursting reports. The relational database can be Cognos Content Database or another supported database.

Design models and log files are not stored in the content store.

IBM Cognos 8 includes the IBM Cognos Content Database as a default content store. You can use the IBM Cognos Content Database as your content store, or you can use other databases, such as Microsoft SQL Server, Oracle, IBM DB2, or Sybase.

The IBM Cognos 8 service that uses the content store is named Content Manager.

Content Manager uses a JDBC (Java DataBase Connectivity) API to access the content store and metric stores. IBM Cognos 8 comes with the JDBC drivers for IBM Cognos Content Database and MS SQL Server. If you are using Oracle, IBM, or Sybase databases, ensure you obtain the appropriate JDBC drivers.

IBM Cognos 8 does not publish the content store schema, but updates the schema periodically, isolating changes from the user through stable user interfaces and APIs.

Much of the information in the content store, such as report results and XML report specifications, is stored as binary large object (BLOB) fields.

PDF results are compressed from creation, to storage, to serving, to the browser. The PDF format does not allow the main body of a report to be compressed, but the page contents, fonts, and images are compressed. Adobe Acrobat Reader uncompresses PDF files at view time.

Report results in other formats, such as HTML, XML, and CSV (comma separated values), are stored in compressed form and are uncompressed by Content Manager before they are sent to a user.