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1answer
47 views

Strangely high writes per second

I'm experiencing some extremely strange behavior on one of our OLTP Servers. Just to provide a bit of background, we have an 'OLTP' which has many large and wide tables. We have 560 tables within it ...
0
votes
1answer
17 views

Monitor volume of data returned to the client application

I've identified ASYNC_NETWORK_IO as our top wait by some distance averaging between 70-77% of wait time for our client application SQL Server. This has been put forward towards the development team ...
2
votes
1answer
90 views

Using Resource Governor and allocate more memory to satisfy high Memory Grant request by queries?

On a SQL Server 2016 database server, I have few queries which are really slow and which ask for more memory (queries are not optimized). This is making the whole database slow as lots of users are ...
1
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1answer
72 views

Does logical reads in RAM appears in wait stats or where?

Concerning execution model of SQLOS (RUNNING state, RUNNABLE queue, WAITER list), what will be the state of a task when there is a logical read of pages in RAM currently going on? If it's a WAITER ...
1
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0answers
49 views

Waiting Tasks on Mirror

I just migrated my primary's synchronous mirror to a new server and I've noticed that there are 150 to 230 waiting tasks on the mirrored instance (based on the activity monitor.) I don't recall if ...
9
votes
2answers
136 views

Increased waits during checkpoint after upgrading to better storage

When we migrated from an older all flash array, to a newer all flash array (different, but well established vendor), we started seeing increased waits in SQL Sentry during checkpoints. Version: ...
14
votes
2answers
2k views

How can wait times be higher than clock time?

When I'm tracking waits with sp_BlitzFirst, I get this detail: <?ClickToSeeDetails -- For 20 seconds over the last 5 seconds, SQL Server was waiting on this particular bottleneck. -- ?> ...
2
votes
2answers
159 views

Lots of short term blockings on SQL Server 2008-R2 database

Seeking experts advise on short term blocking which we are seeing for almost a week now. DB is 15 TB and this Table B where we have lots of blocking - almost 300 in no is 2 TB. While using ...
2
votes
1answer
183 views

Relation of PAGELATCH waits with PAGEIOLATCH and WRITELOG

I am seeing increase in PAGELATCH, PAGEIOLATCH and WRITELOG waits after migration to SQL Server 2017 (from SQL Server 2008). While I can explain increase in PAGEIOLATCH and WRITELOG (we've other disks ...
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0answers
486 views

How to resolve high RESOURCE_SEMAPHORE waits

We are observing high RESOURCE_SEMAPHORE waits after downgrading SQL server 2014 from a higher spec (16 core, 128 GB RAM) to a lower spec (8 core , 55 GB RAM) instance, which is causing higher DB ...
1
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0answers
174 views

Sys.dm_io_virtual_file_stats shows high latency for tempdb writes

We just got a new SAN and I was looking at sys.dm_io_virtual_file_stats to make sure we are seeing an improvement compared to our last SAN. I noticed that all the tempdb files are seeing avg write ...
3
votes
1answer
1k views

MySQL - wait_timeout variable

I've been trying to resolve an issue which I think may be helped by changing the wait_timeout variable in MySQL (5.1.67) on my CentOS machine. So, I updated /etc/my.cnf with the value I want (180), ...
-1
votes
2answers
333 views

Is there any method of looking for Head Blocking history in SQL 2012?

Is there any method of looking for Head Blocking history via DMVs. I have been able to find the subsequent wait details via Extended Events but there doesn't seem to be much information about what ...
1
vote
1answer
168 views

High ASYNC_NETWORK_IO when user locks computer with Excel open

I have a user who gets in at 8AM and leaves at 6PM every day, and every day I see the same strange pattern in SolarWinds DPA. It seems that Excel is refreshing the Query Table when the user locks ...
1
vote
1answer
1k views

MySQL default wait_timeout is 28800 but in my server I can see more than that value

Im using AWS MySQL Aurora, the current wait_timeout is 28800 which is the default one, and interactive_waitimeout is also 28800. But I can see more than the default value.
4
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2answers
5k views

Huge “Network I/O” type resource waits

We have an in-house application, developed in WinDev, that uses a Microsoft SQL Server 2012 SP2 (build 11.0.5058) database running on Windows Server 2008R2. We are experiencing performance issues. At ...
3
votes
2answers
378 views

Wait types with queries

I have a query to find the wait types in which my system is suffering from. WITH [Waits] AS (SELECT [wait_type], [wait_time_ms] / 1000.0 AS [WaitS], ([wait_time_ms] - [...
0
votes
1answer
41 views

Store wait_stats automatically and query it whenever required

I'm learning wait_stats and came up with thought. Is it possible to store wait stats in a table or create a stored procedure or query which will return wait_stats % when we execute query or stored ...
2
votes
1answer
146 views

Hundreds of sessions queued in suspended state

We experience hundreds of sessions going in suspended state on rare occasions. When it happens there is no increase in terms of resource usage - CPU or memory. Rather there is a small amount of ...
2
votes
1answer
1k views

Clarification on signal wait percent

I'm experiencing high Signal Wait percent while CPU utilisation is very low at one of our servers. I have gone through numerous articles online about Signal Waits and understand that it is the time ...
0
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0answers
47 views

Counters to distinguish Insert Hotspot / Page Split by seeing PAGELATCH_EX

Insert hotspot and excessive page splits are common reasons for PAGELATCH_EX. What are the other counters that can be used to confirm whether the wait is from insert hotspot or page split? Note: I ...
3
votes
1answer
379 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 ...
0
votes
1answer
70 views

Does dm_exec_procedure_stats.total_worker_time include signal waits?

Does sys.dm_exec_procedure_stats.total_worker_time include signal waits or only time spent by procedure on scheduler? The reason of question - when number of cores was increased on the server signal ...
2
votes
0answers
664 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 ...
3
votes
1answer
1k views

SQL Server: dm_exec_requests.wait_time vs. dm_exec_sessions.last_request_end_time

We have a third-party Microsoft Access application that uses SQL Server 2012 as its data store. It is a well known issue that Access often does not tell SQL Server that it has received the results of ...
7
votes
2answers
4k views

Is it safe to cancel a PostgreSQL ALTER TABLE query that is waiting on a lock?

We started an ALTER TABLE query hours ago and only recently realized (via pg_stat_activity) that it is waiting on a lock. We discovered the other query that is holding a lock on the table we want to ...
3
votes
1answer
1k views

Confused about sys.dm_io_virtual_file_stats num_of_reads/writes column

I'm trying to use the sys.dm_io_virtual_file_stats DMF to generate so IO wait information across a number of my servers. I came across this post by Paul Randall: http://www.sqlskills.com/blogs/paul/...
1
vote
1answer
460 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. ...
4
votes
1answer
2k views

Print message comes out in batches

I have simple query WHILE ( @counter < 50 ) BEGIN BEGIN TRANSACTION PRINT 'Counter = ' + CONVERT(VARCHAR(4), @counter); WITH CTE AS ( ...
2
votes
1answer
696 views

High Query Wait Times

We are seeing the below query as regularly having very high wait stats. What does this query relate to? System tables? Is it possible to reduce it's wait time? Thanks! select @reservedpages = sum(a....
7
votes
1answer
1k views

Specific TempDB insert of UserDB select results in SOS_SCHEDULER_YIELD to ENCRYPTION_SCAN

One of our production systems has exhibited a problem with a single insertion statement into a temp table from our user database. When I comment out the insert/select, the stored proc in question runs ...
2
votes
1answer
2k views

mysql “Lock wait timeout exceeded” two transaction with different keys indexed

I have set of tables that I need to delete their records with a specific key and insert new records. Different transactions are used one for each key: Transaction 1: DELETE FROM table1 WHERE id=1; --...
1
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3answers
11k views

Why decrease the wait_timeout configuration parameter in MySQL?

Question I'm working on an application that uses a connection pool in Apache Tomcat to communicate with MySQL. I was wondering why would you want to use a smaller wait_timeout than the default of 28,...
2
votes
1answer
1k views

OLEDB Wait Type and Functions

Is there any relationship between the OLEDB Wait Type and functions? Trying to troubleshoot why I would have 77% of my waits as OLEDB wait type when we have no linked servers. I have a vendor database ...
5
votes
1answer
878 views

Need help with ASYNC_NETWORK_IO

We have a SQL Server 2005 server that is serving up 20 websites, one of which is our custom CMS, and a few other micro sites. I am new to this and just started looking at the databases here. The ...
1
vote
2answers
388 views

Shared memory connection experiencing network wait type

I have a poorly written application running a SELECT *, resulting in a 2MB result set every few seconds. I cannot correct this. I am confused though,by the connection encountering ASYNC_NETWORK_IO ...
31
votes
2answers
14k views

Find Queries that Are Causing Waits

Given a certain kind of wait, how do you find which queries are causing those waits safely on a production SQL 2008 R2 Server? In this particular case I am wondering about async_network_io.
1
vote
1answer
11k views

Asynch Descriptor Resize explanation

What do asynch descriptor resize wait events mean on an Oracle 11g database running on Windows 2008 R2? According to My Oracle Support, this event applies to any platform, but the description ...