Does SQL Server cache data?

Hello
I am using SQL Server 2000 SP4
I was going to test my SP in a "clear" environment so I executed
DBCC FREEPROCCACHE
DBCC DROPCLEANBUFFERS
But it seems that still something is cached because if I restart server SP
takes longer time than just after clearing query plan caches.
Moreover could you help me with understanding What actually DBCC
DROPCLEANBUFFERS does? What are those clean buffers?
And if something else is really cached could you tell me how can I empty
that cache or see what is inside.
Thanks in advanceDBCC DROPCLEANBUFFERS will remove the buffers (pages) in cache that are clea
n. But you could have
dirty pages in cache (pages which has been modified since read into cache),
and those are not
removed from cache. To make sure you have no dirty pages in cache, execute C
HECKPOINT in the
database first.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
Blog: http://solidqualitylearning.com/blogs/tibor/
"Alexander Korol" <AlexanderKorol@.discussions.microsoft.com> wrote in messag
e
news:AC2F6CE8-3AE8-4513-A789-EC91AEA28819@.microsoft.com...
> Hello
> I am using SQL Server 2000 SP4
> I was going to test my SP in a "clear" environment so I executed
> DBCC FREEPROCCACHE
> DBCC DROPCLEANBUFFERS
> But it seems that still something is cached because if I restart server SP
> takes longer time than just after clearing query plan caches.
> Moreover could you help me with understanding What actually DBCC
> DROPCLEANBUFFERS does? What are those clean buffers?
> And if something else is really cached could you tell me how can I empty
> that cache or see what is inside.
> Thanks in advance|||Thanks a lot

Does RS cache AD groups?

Hi,
I've run into a few problems, and I think RS may be to blame. I was hoping
one of the experts out there would be able to offer some input.
I set up role-based security in RS as follows:
Report 1, 2, and 3: all authenticated users assigned browser role
Reports 4, 5: a select group (AD security group named
"ReportingCommissions") assigned browser role
I added a new user to the ReportingCommissions group via Active Directory
Users and Groups and replicated both domain controllers.
After that, the user was not able to see report 4 or 5 in his list of
reports in the folder. If I added his exact Windows username to report 4 as
a browser, he can see it immediately.
Rebooting the server that houses the RS web app did the trick - the user can
now see both folders as a member of the group ReportingCommissions.
This leads me to believe that RS is somehow caching the list of members of
each Windows security group assigned to roles in RS. I can see why this
would be done, as it would slow folder browsing down to enumerate these
groups for every report in the current folder. Whereas matching up a
username should be much quicker, so there is no need to cache that info.
Is my assumption correct, or am I missing something? If the group
memberships are being cached in RS, can you tell me for how long? Is there
any way to clear that cache or add to a group's membership within the db?
Restarting the ReportServer service did not help, but I didn't try
restarting any of the IIS-related services.
--
Regards,
Jake Marx
MS MVP - Excel
www.longhead.com
[please keep replies in the newsgroup - email address unmonitored]Has anyone run across this before? Any answers from MS? Thanks in
advance...
--
Regards,
Jake Marx
MS MVP - Excel
www.longhead.com
[please keep replies in the newsgroup - email address unmonitored]
Jake Marx wrote:
> Hi,
> I've run into a few problems, and I think RS may be to blame. I was
> hoping one of the experts out there would be able to offer some input.
> I set up role-based security in RS as follows:
> Report 1, 2, and 3: all authenticated users assigned browser role
> Reports 4, 5: a select group (AD security group named
> "ReportingCommissions") assigned browser role
> I added a new user to the ReportingCommissions group via Active
> Directory Users and Groups and replicated both domain controllers.
> After that, the user was not able to see report 4 or 5 in his list of
> reports in the folder. If I added his exact Windows username to
> report 4 as a browser, he can see it immediately.
> Rebooting the server that houses the RS web app did the trick - the
> user can now see both folders as a member of the group
> ReportingCommissions.
> This leads me to believe that RS is somehow caching the list of
> members of each Windows security group assigned to roles in RS. I
> can see why this would be done, as it would slow folder browsing down
> to enumerate these groups for every report in the current folder. Whereas
> matching up a username should be much quicker, so there is no
> need to cache that info.
> Is my assumption correct, or am I missing something? If the group
> memberships are being cached in RS, can you tell me for how long? Is
> there any way to clear that cache or add to a group's membership
> within the db? Restarting the ReportServer service did not help, but
> I didn't try restarting any of the IIS-related services.|||I got a response for you from Tudor Trufinescu, a dev lead. He says he's
answered this often enough that it was time to create a blog entry. It's at
http://blogs.msdn.com/tudortr/archive/2004/10/27/248846.aspx and it mentions
a KB article as well.
--
Sincerely,
Stephen Dybing
This posting is provided "AS IS" with no warranties, and confers no rights.
"Jake Marx" <msnews@.longhead.com> wrote in message
news:eBAH5z3uEHA.3976@.TK2MSFTNGP09.phx.gbl...
> Has anyone run across this before? Any answers from MS? Thanks in
> advance...
> --
> Regards,
> Jake Marx
> MS MVP - Excel
> www.longhead.com
> [please keep replies in the newsgroup - email address unmonitored]
>
> Jake Marx wrote:
>> Hi,
>> I've run into a few problems, and I think RS may be to blame. I was
>> hoping one of the experts out there would be able to offer some input.
>> I set up role-based security in RS as follows:
>> Report 1, 2, and 3: all authenticated users assigned browser role
>> Reports 4, 5: a select group (AD security group named
>> "ReportingCommissions") assigned browser role
>> I added a new user to the ReportingCommissions group via Active
>> Directory Users and Groups and replicated both domain controllers.
>> After that, the user was not able to see report 4 or 5 in his list of
>> reports in the folder. If I added his exact Windows username to
>> report 4 as a browser, he can see it immediately.
>> Rebooting the server that houses the RS web app did the trick - the
>> user can now see both folders as a member of the group
>> ReportingCommissions.
>> This leads me to believe that RS is somehow caching the list of
>> members of each Windows security group assigned to roles in RS. I
>> can see why this would be done, as it would slow folder browsing down
>> to enumerate these groups for every report in the current folder. Whereas
>> matching up a username should be much quicker, so there is no
>> need to cache that info.
>> Is my assumption correct, or am I missing something? If the group
>> memberships are being cached in RS, can you tell me for how long? Is
>> there any way to clear that cache or add to a group's membership
>> within the db? Restarting the ReportServer service did not help, but
>> I didn't try restarting any of the IIS-related services.
>|||Stephen Dybing [MSFT] wrote:
> I got a response for you from Tudor Trufinescu, a dev lead. He says
> he's answered this often enough that it was time to create a blog
> entry. It's at
> http://blogs.msdn.com/tudortr/archive/2004/10/27/248846.aspx and it
> mentions a KB article as well.
Thanks, Stephen. I thought I had waited more than 15 minutes, but I was
probably just being impatient. I don't think our security group updates
will be that frequent, so I'll probably have users wait the 15 minutes (or
restart the w3 publishing service if we can't wait).
Thanks again - I appreciate the followup.
--
Regards,
Jake Marx
MS MVP - Excel
www.longhead.com
[please keep replies in the newsgroup - email address unmonitored]