How to check if table or index bound to data cache loaded in memory?

Question

In my system, thare are many named data caches created and certain objects bind to those data cache.
For example, I have a large table mytab which is bound to data cache mycache.
When I issue a sql like select * from mytab where x=y, run it at first time is is very slow.  run it again and again. then it very fast. it means data loaded in cahce and ready for same query.
Question:
1. How can I know if the table mytab has been loaded in data cache mycache?
2. How to load mytab into data cahce mycache one time for all query in the feature?

Answer 1

one way to monitor is:
select CacheName,DBName,OwnerName,ObjectName,IndexID,sum(CachedKB) as "CachedKb"
from master..monCachedObject
group by CacheName,DBName,OwnerName,ObjectName,IndexID
order by CacheName,DBName,OwnerName,ObjectName,IndexID
But, you should understand that caches have a finite size, and caches contain "pages" of objects including data pages, index pages, and LOB pages.  Also, caches may have different pool sizes, so a page can be in only one cache pool.  So, if you want  a table and all of it's indexes, text/image pages  to be loaded into a dedicated cache, you need a large enough cache to fit all of those pages, and decide which buffer pool you want them in (typically either the 1 page pool, or the 8 page pool).
Then, simply execute SQL (or dbcc) commands that access all of those pages in the manner you wish to find them in the cache.  For example, two statements, one that scans the table using 2k reads, and another that scans the index (mytab_ind1) using 2k reads.
select count(*) from mytab plan '( i_scan mytab_cl mytab) ( prop mytab ( prefetch 2 ) ( lru ) )'
select count(*) from mytab plan '( i_scan mytab_ind1 mytab) ( prop mytab ( prefetch 2 ) ( lru ) )'
etc etc.
used count(*) to limit result sets of examples