Memory used by each SQL Server Databases

As you know SQL Server stores database data and index pages in memory in an area know as the Buffer Pool. Using my trusty friend Google, I researched an answer, here you go...

SELECT

(CASE WHEN ([is_modified] = 1) THEN 'Dirty' ELSE 'Clean' END) AS 'Page State',

(CASE WHEN ([database_id] = 32767) THEN 'Resource Database' ELSE DB_NAME (database_id) END) AS 'Database Name',

COUNT (*) AS 'Page Count'

FROM sys.dm_os_buffer_descriptors

GROUP BY [database_id], [is_modified]

ORDER BY [database_id], [is_modified];

GO