SQL Server - sys.dm_os_buffer_descriptors

select 
   db_name(buf.database_id) db,
   buf.file_id,
   buf.page_id,
   buf.page_level,
-- alo.type                  allocation_type_id,
   alo.type_desc             allocation_type,
   buf.page_type,
   alo.data_space_id,
   alo.total_pages,
   alo.used_pages,
   alo.data_pages,
-- buf.allocation_unit_id,
   buf.row_count,
  buf.free_space_in_bytes,
   buf.is_modified,
   buf.numa_node,
   buf.read_microsec,
   buf.is_in_bpool_extension,
   alo.container_id
from
   sys.dm_os_buffer_descriptors  buf     join
   sys.allocation_units          alo on buf.allocation_unit_id = alo.allocation_unit_id

select
-- count(*),
   page_type
from
   sys.dm_os_buffer_descriptors
group by
   page_type
order by
   page_type
--
-- DATA_PAGE
-- IAM_PAGE
-- INDEX_PAGE
-- TEXT_MIX_PAGE