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0
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1answer
17 views

ACCESS_METHODS_DATASET_PARENT Problem

We had an AlwaysOn Async replica we had some problems so we deleted the availability group After that the database and CPU seem to work abnormally It's very slow and we have waittype = LATCH_EX , ...
1
vote
1answer
59 views

DIRTY_PAGE_POLL without activated Indirect Checkpoint

Since I encounter some performance issues on my SQL Server 2014 (12.0.2370.0 (X64)) I'm dealing with enormes amounts of different wait types. One of the top 5 wait type is "DIRTY_PAGE_POLL". I've ...
1
vote
2answers
65 views

SOS_SCHEDULER_YIELD - Prevent a Proc from giving up the Processor Time

I've got a process which about once a month at times unrelated (or as far as we can tell) goes into SOS_SCHEDULER_YIELD State. This process blocks our main data entry pipeline and brings the entire ...
6
votes
1answer
157 views

How to solve blocking on tempdb

I am having tempdb contention (I guess, at least) on one of the servers (SQL Server 2008 R2). Both the blocker and the waiters (10 of them) has PAGELATCH_EX wait type on database tempdb and all ...
1
vote
1answer
57 views

Scalability of concurrent log restore for different databases on SQL Server

Are there any locks or resource blocking/contention (beyond IO capacity) between two sessions, which restore logs for two different databases with norecovery? Same about restore logs with recovery? ...
2
votes
1answer
522 views

WAIT STATS - high Wait Time on ASYNC_IO_COMPLETION

I currently look at my wait stats. I followed best practices explained by Paul Randal and go through the documents he references. Looking at the statistic slices I take once / day for a while now ...
1
vote
0answers
100 views

How can I have long waits on Tracewrite, when I haven't run Profiler?

I recently setup a SQL Server which is used only ot run a sharepoint Server. I love to query my wait stats, just to see what we are waiting on. Most of the wait stats are fine, and I know where they ...
0
votes
1answer
35 views

Large Sleep counts causing THREADPOOL wait?

When I run sp_whoisactive throughout the day, I usually see we have around 500-700 connections on our server. We are occasionally getting threadpool waits and high signal wait ratios (so we are thread ...
4
votes
1answer
2k views

What is the Wait Type “QDS_Shutdown_Queue” referring to?

I'm gathering wait types on a load test environment, and the second biggest wait type is QDS_SHUTDOWN_QUEUE. The stats are coming from sys.dm_os_wait_stats, but I can't find any documentation that ...
2
votes
2answers
163 views

Reading ASYNC_NETWORK_IO wait stats

I was troubleshooting some bad performance for a client yesterday and identified that there was a missing index for a particular set of queries that were heavily used (this was for an ERP applicaton: ...
0
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0answers
62 views

How to tune a sql server for a specific process in particular?

I have a specific process that I am want to tune for in a sql server DEV server. The DEV server and the LIVE server are equal, just the DEV has less memory. Both LIVE and DEV read data from the same ...
0
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0answers
211 views

PREEMPTIVE_OS_FILEOPS when querying Filestream

I've have a table which contains a Filestream column, when I query the table as follows: SELECT ID, FileContent --, * FROM dbo.Files AS f WHERE FileContent IS NOT NULL AND ID = '...
4
votes
1answer
91 views

PAGEIOLATCH wait type

I'm trying to get a better understanding of how serious this wait type is. I'm using sp_WhoIsActive stored procedure. Our DBAs don't seem to know much about this wait type. But I often see it when I ...
4
votes
1answer
171 views

How to find out how much i/o resources a task, session, request or transaction is currently using?

How to find out how much i/o resources a task, session, request or transaction is currently using? by task I mean the DMV called DMV sys.dm_os_tasks. by session I mean the DMV sys.dm_exec_sessions ...
9
votes
1answer
149 views

Blocked sessions waiting with PAGELATCH_* wait types?

Edited : Why are sessions reporting being blocked but waiting with PAGELATCH_*, and not LCK_M_ related wait types? I previously assumed that SQL server would only report blocking sessions in the ...
1
vote
0answers
24 views

How to identify a process that has been cancelled?

How can you identify a process that has been cancelled? for example: I was running this dynamic sql - via a linked server: declare @sql nvarchar(max) declare @i int declare @z int DECLARE @vCrlf ...
1
vote
0answers
66 views

How can I reduce OLEDB wait type in a SSAS linked server connection?

I have recently created a linked server to one of my SSAS servers. when I go ahead and open the catalogs, to see which ssas databases I have there, I use the following procedure: create procedure ...
2
votes
0answers
86 views

PAGEIOLATCH_SH and WRITELOG waits

We have a slow overnight process which I was asked to look at with the top waits being PAGEIOLATCH_SH and WRITELOG I have been collecting information from sys.dm_io_virtual_file_stats and can see ...
3
votes
0answers
65 views

Different Disk Drive Same Backend Storage

I have a database running on a VM which is getting hammered during a large load, in particular I can see waits of WRITELOG happening. My initial thought is to split the files out on to their own ...
2
votes
1answer
53 views

Non Buffer Latch - Forefront Identity Manager

We are using Forefront Identity Manger and we are doing an initial load to which we are experiencing slow performance. I always start with wait types for such things and can see %30 CXPACKET, %25 ...
3
votes
1answer
198 views

Excessive CPU use in vendor SQL Server DB

Background: I've got a SQL Server 2012 DB provided by a vendor so modification of queries and tables is limited. We do own the DB though, so we can add and maintain indexes. Indexes haven't been ...
6
votes
1answer
176 views

Disk I/O and PAGEIOLATCH_XX

We have been having CPU issues with one of our servers lately and while we have been looking into this we have also noticed queries running slowly with waits of PAGEIOLATCH_XX. In particular, a ...
1
vote
2answers
219 views

High SOS_SCHEDULER_YIELD and Signal Waits

I have run Paul Randals wait script and can see SOS_SCHEDULER_YIELD is at 60% with an average signal wait of 10ms. I have also run a script to find out the what percentage of my waits are signal ...
3
votes
2answers
2k views

CXPACKET SUSPENDED and NULL wait type

I was was running the query in this article: http://sqlity.net/en/708/why-cxpacket-waits-are-not-your-performance-problem/ To see what my threads were waiting on in regards to a suspended query with ...
3
votes
3answers
136 views

Why is sql server waiting for acknowledgment?

I have an application that often request a big set of rows [about 20K] from a sql view, in the mean time other applications can't update the table from where the data comes from, the update query's ...
3
votes
1answer
90 views

What is the PREEMPTIVE_REENLIST wait type in Microsoft SQL Server 2008 R2

This is not urgent, just curiosity. QUESTION: I was trying to troubleshoot a slow server today, and I came across a high figure for a wait type called PREEMPTIVE_REENLIST. I'm not able to find this ...
3
votes
1answer
7k views

resource wait SQLCLR - wait_type CLR_SEMAPHORE by SPID 0

UPDATE In the comments under Aaron's post is an extensive explanation why I want to find this out, please read it if you want to know. The system is running some ETL, reporting services and a ...
1
vote
2answers
2k views

PAGEIOLATCH_SH and LCK_M_IX wait type

I'm seeking for a resolution into wait types I observe on one of my servers. I've been keeping wait statistics for a long time and can positively say that the top two are PAGEIOLATCH_SH and LCK_M_IX ...
2
votes
0answers
131 views

what could be a good value for “Cost Threshold for Parallelism”? [closed]

I would like to reduce the WAIT time that I have on the CXPACKETS, as you can see on the pictures attached. I believe I could raise the cost threshold for parallelism to 50, because 5 is too low. I ...
1
vote
1answer
99 views

Wait Stats, Server Up Time and CXPACKET

I have been looking at the following post and using the query to look at my top wait stats: http://www.sqlskills.com/blogs/paul/wait-statistics-or-please-tell-me-where-it-hurts/ My top wait stat is ...
4
votes
2answers
325 views

Can WAITFOR increase CXPACKET waits?

If I have some T-SQL code like this: While @done<1 Begin WAITFOR DELAY '00:00:30'; Set @done=<some select statement> End Is this likely to increase waits for CXPACKET? Presumably the other ...
1
vote
1answer
299 views

sql server service broker

For the last few days the service broker command which run from master database is consuming much more RESOURCES than before. The Impact on the Database is high (from the bad side), It causes for ...
8
votes
0answers
902 views

Troubleshooting THREADPOOL Waits [closed]

From everything I have read, THREADPOOL waits occur when a task is waiting for a worker thread. A high amount of THREADPOOL waits typically means you are running out of available worker threads. ...
2
votes
3answers
2k views

Collecting Wait Stats

We currently use a monitoring tool which shows us our top wait stats either by number of waiting tasks or total wait time. Below are the wait stats by number of tasks waiting and also wait time per ...
3
votes
2answers
4k views

Ideal values for wait time in SQL server

This is related to my own post here The SQL server starts everyday at 8:30 AM and stops around 9:30 PM.( So wait times will reset everyday) SQL server will be used by around 60 users simultaneously(...
0
votes
0answers
294 views

SLEEP_TASK and PAGELATCH_XX peaking after upgrade to R2 SP1

I wanted to just add a comment to this question: SLEEP_TASK Wait Type in SQL Server - What does it indicate? But I'm having not only SLEEP_TASK wait but also PAGELATCH_SH and PAGELATCH_EX wait types. ...
7
votes
2answers
1k views

Intermittent RESOURCE_SEMAPHORE_QUERY_COMPILE Wait Stats

I'm trying to troubleshoot some intermittent CPU spikes that we're witnessing on one of our production SQL Servers. We're running SQL Server 2008 R2 Standard Edition with 28 GB RAM and 4 CPU cores. ...
7
votes
2answers
813 views

SQL Server performance: PREEMPTIVE_OS_DELETESECURITYCONTEXT dominant wait type

I received a call yesterday from a customer who was complaining about high CPU usage on their SQL Server. We're using SQL Server 2012 64 bit SE. Server is running Windows Server 2008 R2 Standard, 2.20 ...
8
votes
2answers
18k views

High CXPACKET and LATCH_EX waits

I am having some performance issues with a data processing system which I am working on. I have gathered wait stats from a one hour peroid which show a large amount of CXPACKET and LATCH_EX wait ...
3
votes
1answer
359 views

Why is there ASYNC_NETWORK_IO wait type on Shared Memory connections?

I have an app (windows service) local to the SQL Server box. It calls a sproc on the SQL Server box that returns a ton of data and thus causes ASYNC_NETWORK_IO wait. The database connection from is ...
9
votes
1answer
15k views

Is ASYNC_NETWORK_IO wait type anything to worry about?

In looking at the list of sprocs that take long time to execute, one stands out as causing the most wait. However, most of that wait (81%) is ASYNC_NETWORK_IO and I know why: the sproc transfers ...
5
votes
1answer
1k views

What does the wait type PREEMPTIVE_XE_CALLBACKEXECUTE mean?

I have two instances in the last week where a DROP command for an Extended Events session has taken over a day to complete, sitting with the wait: PREEMPTIVE_XE_CALLBACKEXECUTE. Can anyone explain ...
9
votes
1answer
8k views

Troubleshooting SOS_SCHEDULER_YIELD wait

Running our corporate ERP (Dynamics AX 2012), I noticed our production environment seemed much slower than our development systems. After performing the same activities in both the development and ...
7
votes
1answer
1k views

LATCH_EX Waits on Resource METADATA_SEQUENCE_GENERATOR

We have a process that generates an inventory report. On the client side, the process splits of a configurable number of worker threads to build a chunk of data for the report that corresponds to one ...
6
votes
3answers
11k views

Investigating high SQL waits, especically LCK_M_U

Recently I have been struggling with SQL server performance and although we have fixed a huge multitude of basic errors in the config it is still performing badly. To clarify it is not overall ...
2
votes
4answers
6k views

Select from linked server to local server causing waits on both sides

The queries in question are here: http://pastie.org/4833351 Run individually, each of these queries runs through (albeit slow). Run as a group, it just sits there, showing either OLEDB waits on the ...
4
votes
1answer
2k views

Is the SQLTRACE_FILE_BUFFER wait type documented? What does it indicate?

We run a background task on one of our servers which polls sys.dm_exec_requests for long-running queries, gathering diagnostic information when it finds them, including wait type. I'm seeing a number ...
6
votes
1answer
689 views

Attempting to tune a Sharepoint site using SQL Server Waits and Queues

I'm pretty new to this performance tuning with Waits and Queues thing - fascinating, but also not always all that intuitive... Right now, a customer of mine has a SQL Server 2008 64-bit Enterprise ...
6
votes
2answers
42k views

How to troubleshoot enq: TX - row lock contention?

I have the following situation. I have RAC. On both nodes there are the locks. On the First Node SID EVENT USERNAME BLOCKING_SESSION ROW_WAIT_OBJ# OBJECT_NAME ...
4
votes
3answers
5k views

PageIOLatch_Sh waits noticed after tuning an index

Lately, a lot of queries to the database are timing out. While investigating I found that queries are in the suspended state with wait_type as PageIOLatch_Sh. I have not noticed so many queries being ...