Questions tagged [dmv]

DMV in SQL Server is a catch-all term for Database Management Views [& Functions]. Technically they are all now DMOs (Database Management Objects) however the term DMV is still widely understood and accepted by most.

Filter by
Sorted by
Tagged with
2
votes
0answers
255 views

Collect information about currently running queries only when client timeout occurs

We would like to be able to collect information about all currently running queries when (and only when) a client timeout occurs in SQL Server 2008. I know I can collect information about the client ...
3
votes
1answer
156 views

Understanding SQL Server plan cache

I've been reading about the SQL Server plan cache and optimizing for adhoc workloads, etc. I'm fairly new to the topic and have a few general questions to help paint a better picture: Suppose I have ...
2
votes
0answers
390 views

plan_generation_num keeps incrementing, why?

I have a query that is executed using sp_executesql code is as follows DECLARE @rsk NVARCHAR(1) = '1', @ppCityID NVARCHAR(3); SET @ppCityID = CAST(@cityID AS NVARCHAR(3)); exec sp_executesql N'...
2
votes
1answer
381 views

Find statements related to sys.dm_db_missing_index… tables (SQL Server)

I have read up different articles related to SQL Server 2008 on how to find out missing indexes using the tables sys.dm_db_missing_index_groups, sys.dm_db_missing_index_group_stats etc. One thing I'...
0
votes
1answer
217 views

In sys.dm_os_memory_cache_entries view, what does original cost mean?

Looking at a couple of DMVs, and trying to see if I can programmatically figure out the cost of the cached plans in my SQL Server. I'm hoping that column represents the same concept of cost that is ...
7
votes
3answers
1k views

Why is there a difference between these transaction DMVs in SQL Server 2008 R2?

When I execute the two queries below, SELECT session_id, transaction_id FROM sys.dm_tran_session_transactions; AND SELECT session_id, request_id, at.transaction_id FROM sys....
2
votes
2answers
2k views

Get Results from DMV Query into SQL Server Table

today I began to troubleshoot an issue that I was asked to resolve, and for the first time I found myself querying in the SSAS database. I obtained a very useful set of results (who was connecting to ...
2
votes
1answer
103 views

Synchronize Queries Retrieving Sessions And Locks From DMVs

I have a SQL script that I run when I want to see what is happening in the database. The script has many queries that return information from DMVs, but the two I use most are "Requests" (sys....
12
votes
2answers
871 views

Setting READ UNCOMMITTED when reading DMVs

I've seen several people call SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED before reading system DMVs. Is there ever any reason to do this, assuming you aren't mixing calls to DMVs and tables in ...
3
votes
0answers
458 views

Are the following statements concerning sys.dm_exec_requests true?

Parallel plans mean that cpu_time can be greater than total_elapsed time. Therefore, per-query wait time is not possible to determine accurately from DMVs on servers with more than one CPU thread. ...
0
votes
2answers
252 views

Is there a combination of columns in sys.dm_exec_sessions that is unique per the server?

In SQL Server, each session has its own spid. Spids are unique at any given notice, but spids, like process and thread identifiers in the OS are recycled. However sys.dm_exec_sessions has other ...
6
votes
1answer
181 views

Ok to drop indexes on FK's if they have no stats in the DMVS

I have used the well known query below from Kevin Kline to check for unused indexes. Several indexes created on Foreign keys returns no read stats, only writes. Are you 100% safe to drop these ...
9
votes
1answer
9k views

what is difference between last_worker_time and last_elapsed_time in DMV sys.dm_exec_query_stats?

what is meaning of last_worker_time and last_elapsed_time in DMV sys.dm_exec_query_stats and what is differnce between them? when I fire below query SELECT TOP 20 qs.last_worker_time, qs....
7
votes
1answer
1k views

SQL Server 2008 R2 DMV Question

I have a query to retrieve the Top 10 queries based on total logical reads from the dm_exec_query_stats DMV. SELECT TOP 10 SUBSTRING(qt.TEXT, (qs.statement_start_offset/2)+1, ((CASE qs....
4
votes
2answers
193 views

Is it possible to determine what part of a stored procedure is currently executing?

Say I have a stored procedure like this (assume that the table schemas are fine): CREATE PROCEDURE p_MyProc AS INSERT MyTable SELECT Col1 FROM Table1 INSERT MyTable SELECT Col2 FROM Table2 INSERT ...
8
votes
2answers
7k views

What units are 'reads' and 'writes' in dm_exec_query_stats

MSDN describes the various logical / physical read and write columns in dm_exec_query_stats as: Number of physical reads performed the last time the plan was executed. Those columns are all 64 bit ...
14
votes
5answers
22k views

Improve performance of sys.dm_db_index_physical_stats

During a maintenance job, I'm trying to get a list of fragmented indexes. But the query is extremely slow and takes over 30 minutes to execute. I think this is due to a remote scan on sys....
2
votes
1answer
3k views

Resource Usage Statistics by Login

Is there a way to get resource usage statistics by login in SQL Server? Ideally, I'd like to have a version of sys.dm_exec_sessions that tracks usage for all sessions, rather than just the currently-...
3
votes
2answers
208 views

Inconsistent information from different DMVs

I've a server with 12 GB of physical RAM. I just lowered its 'Max Server Memory (MB)' setting from 10 GB to 8 GB. If I look at the processes' committed memory in Perfmon, I see: select * from sys....
2
votes
2answers
396 views

In SQL Server 2008, in DMV sys.dm_db_index_phsicial_stats, what does compressed_page_count mean in comparision with page_count

In SQL Server 2008, DMV sys.dm_db_index_physical_stats, what does compressed_page_count mean in comparison with page_count. I have a table with the following info: Object_id Index_type_desc ...
2
votes
1answer
1k views

Index physical stats DMV - Object ID/table not found

I have installed SQL Server 2012 RC0 on my laptop recently and I was trying a demo which illustrates how shrink database will cause fragmentation. I created a table, a clustered index on the identity ...
4
votes
1answer
1k views

sys.sysprocesses versus DMVs

I've seen a couple of blog posts where fairly knowledgeable sounding MVPs are still using sys.sysprocesses rather than the recommended DMVs: sys.dm_exec_connections, sys.dm_exec_sessions and sys....
4
votes
2answers
3k views

sys.database_files / sys.filegroups VS sys.sysfiles / sys.sysfilegroups

These catalog views seem to show the exact same data. What is the point of having multiple system views that seem to show the same thing? Here is how I proved it is the same data: select fil....
4
votes
2answers
873 views

How do I track the usage of XML indexes?

My XML indexes are not listed in sys.dm_db_index_usage_stats Does this mean they aren't being used? Or does this particular DMV not track XML index usage? (Books Online doesn't appear to answer the ...
5
votes
2answers
1k views

DMV Queries as Perfmon Counters

Certain DMV queries that return various statistics that increment since boot would be useful as perfmon counters. For example, take: SELECT wait_type, wait_time_ms FROM sys.dm_os_wait_stats; Most ...