Internal SSAS DMV's can be used to gather MetaData information about SSAS Objects.
Following are the list of DMV's which enable to query Cube, Dimension, Hierarchies, Performance information etc using SSMS.
$SYSTEM.MDSCHEMA_CUBES
$SYSTEM.MDSCHEMA_DIMENSIONS
$SYSTEM.MDSCHEMA_FUNCTIONS
$SYSTEM.MDSCHEMA_HIERARCHIES
$SYSTEM.MDSCHEMA_INPUT_DATASOURCES
$SYSTEM.MDSCHEMA_KPIS
$SYSTEM.MDSCHEMA_LEVELS
$SYSTEM.MDSCHEMA_MEASUREGROUP_DIMENSIONS
$SYSTEM.MDSCHEMA_MEASUREGROUPS
$SYSTEM.MDSCHEMA_MEASURES
$SYSTEM.MDSCHEMA_MEMBERS
$SYSTEM.MDSCHEMA_PROPERTIES
$SYSTEM.MDSCHEMA_SET
References :
Checking Cube performance:
http://blogs.microsoft.co.il/blogs/yanivmor/archive/2010/01/27/dmvs-for-analysis-services.aspx
Querying SSAS:
http://richardlees.blogspot.com/2010/07/querying-analysis-services-for-cube.html
http://bennyaustin.wordpress.com/2011/03/01/ssas-dmv-queries-cube-metadata/
http://msdn.microsoft.com/en-us/library/ms126079.aspx
