During investigation problem with disk i found some issue, that every 2 minutes is writing on disk , it looks like to mdf file of database, but in almost 6-8milions Bytes / sec , it is about 1-2 sec , but every 2minutes... this is normal behaviour ? this is synchonyous writing to disk from memory.
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What's the best practice when it comes to disk write caching? Is it better to enable or disable this feature?
Thanks.
I have do some benchmark test between the "Principle", "Mirror" and "Witness", things seems normal, the System usage (CPU, Disk Read/Write) on the "Witness" is very small and the CPU usage on Principle and Mirror is similar, However....
For the "Disk Write Bytes/sec", the usage on Principle is 200,000 and the Mirror is 1,500,000, the mirror server is talking about x7 times Disk Write Bytes/sec on the Mirror.
I cannot think of any reason why the Disk Write Bytes /sec is so much higher than the Principle, can somebody help me?
We are collecting perfmon counters every 15 second . Among the counters is Average Disk sec/Write . I under stand that it is the average time taken in second to write a data to the disk. However I do not understand what the is quantum of data written in one second. What is the measure or unit of data in Average Disk sec/Write or is it simply the average time taken for an I/O write request.
View 4 Replies View RelatedI am going put in the whole query but my question is on changing a datediff minutes amount into DD:HH:MM.
Query is:
select c.APPLICANT_ID as [Applicant ID], aetc.EVENT_TYPE as [Event Type],
cast(aetr.CREATE_DATE as date) as [Registration Date],
cast(aetc.CREATE_DATE as date) as [C Creation Date],
datediff(mi,cast(aetr.CREATE_DATE as datetime),cast(aetc.CREATE_DATE as datetime)) as [time diff],
[Code] .....
I want this as dd:hh:mm rather than just minutes.
Currently this field is just minutes so a figure such as 20, depending on the time difference between the 2 dates.
I have tried the convert statement convert (char(5) ...........,108) within this but that's not working and I have used floor before to do this type of thing but not sure where that should go.
I need to be able to add minutes to a datetime value, which only cover working hours.
I have a holiday table as below:
Examples: (dd/MM/yyyy hh:mm)
Date..........Description
01/01/2015 New Years Day
26/12/2014 Boxing Day
25/12/2014 Christmas Day
25/08/2014 August Bank Holiday
Our Business hours are 08:00-18:00 Mon-Fri (unless the day is in the holiday table)
Start Date............Minute to Add......Expected outcome
01/09/2014 10:00........30...................01/09/2014 10:30
01/09/2014 17:00........65...................02/09/2014 08:05
29/08/2014 17:00........65...................01/09/2014 08:05
22/08/2014 17:00........65...................26/08/2014 08:05
31/08/2014 02:30........65...................01/08/2014 09:05
01/09/2014 19:00........65...................02/08/2014 09:05
01/09/2014 10:00........3005...............08/09/2014 10:05
22/08/2014 17:00........3005...............01/09/2014 17:05
I have tried to create a function to do this (fn_pp_AddMinutesWithinWorkingHours(@StartDate,@Minutes)) but I am unable to come up with a solution which factors in everything correctly.
I am looking to be able to add 15 minutes to a time value that is in character format. here is sample data:
0530
0545
0600
0615
0630
0645
0700
0715
0730
0745
Whenever there is a leading zero, I need to preserve that as well. Here is an example of what I an looking for:
0545 + 15 = 0600
0600 + 15 = 0615
1345 + 15 = 1400
My table as data as follow,
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[table_Data]') AND type in (N'U'))
DROP TABLE [dbo].[table_Data]
GO
/****** Object: Table [dbo].[table_Data] Script Date: 04/21/2015 22:07:49 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[table_Data]') AND type in (N'U'))
[code].....
hello,all
I am new to Sql 2000,I installed sql 2000 database in C disk,but Now I found my C disk space is smaller than before,So I want to move my databse(include data and structure) from C Disk to D Disk(its space is very large) .
is it possible to do it ?
if its can be done ,do I need to change my asp.net program source code (exp: chaneg my crystal report connectstring ) ?
thanks in advanced!
We have a couple of 200GB databases that are recreated each night on a SQL2012 server connected to a disk array. The SQL disk is an auto-tiered combo of 10k and 7k drives in a RAID1 lun, and both data and log files are there.
Recently, some room has opened up on an older array that contains smaller, but many, 15k drives that I could use in a RAID1 config. Being that I'd like to split up the mdf and ldf files, which would you put onto the new (faster) disk?
EDIT: Add'l info: the only current performance issues I see in the SQL Log are FlushCache messages occuring throughout the night, when all activity happens for this DB. Things like this: "FlushCache: cleaned up 388690 bufs with 23474 writes in 409743 ms (avoided 179747 new dirty bufs) for db 47:0"
Is there anyway to check if server is having disk latency or IO issues?Found below in SQL error log
Date10/1/2014 8:28:58 AM
LogSQL Server (Current - 10/1/2014 12:00:00 AM)
Sourcespid10s
Message
SQL Server has encountered 8500 occurrence(s) of I/O requests taking longer than 15 seconds to complete on file [D:Fin.mdf] in database [Fin] (5). The OS file handle is 0x0000000000001368. The offset of the latest long I/O is: 0x0001104a7da000
We can find free space on disks with 'xp_fixeddrives'.
I need script to find all disk size(total sizecapacity) in the servers?
We're having some issues with where our backups write to, so I've been watching and monitoring the performance, when I noticed today that restore labelonly from disk has been running almost non stop for the past few hours.
The account running the query is the SQL Server's service account, and the program is "Microsoft SQL Server".
Every minute or so the SPID changes which made me think it was related to the transaction logs, the "restore labelonly" runs for as long as each database in the transaction log backup.
Example: Database A transaction log backup takes 1 minute and the SPID XX for restore labelonly runs 1 minute
Database B transaction log backup starts and there is a new SPID for restore labelonly.
I hope this makes sense because I normally don't see this restore labelonly running.
I have a windows 2012 cluster environment that consists of two SQL servers nodes with Quorum disk configured as witness.
Manual failover between nodes is working fine, however the sql instance virtual is not seeing the Quorum disk.
Moreover the Quorum disk has the same number as another cluster storage disk, is that considered a problem?
When I move the SQL instance from a node to anohter, should the Quorum Disk change ownership as well to that destination node ? if it is not changing ownership what would be the problem??
Can we backup a DB from SQL Server 2012 (Ent. edition) two node cluster to a local disk ?. Is it possible ?
View 7 Replies View RelatedI have a SQL Server 2012 DB in Full recovery mode that has never had a TLOG backup. the log is huge 200+GB.
I tried doing a transaction log backup but there is not enough space on the Disk.
How can I reclaim this log space in SQL Server 2012?
I am wondering what would be the best disk/RAID setup for a Windows server 2008 R2 OS and SQL Server 2012 database that has heavy read/write. I have the following disks I can use:
4x 15k 146GB
2x 10k 600GB
According to the server build requirements for the application, I need 100GB for the OS and 290GB for the drive containing the SQL mdf there are no stated requirements for the ldf, but would like to know if it should be allocated elsewhere?I should do RAID 10 for the 15k drives for SQL and RAID 1 for the OS on the 10k.
Under the maintenance plan, i run full backup at the same path and it was successful. The maintenance plan for selected database was run success.
BUT when i want to write the backup report "Write a report to a text file" i receive this error in maintenance plan "view history"
Access to the path 'F:MSSQL11.APPSPRDMSSQLBackupBackup LogCARSCARS DB Backup_Subplan_1_20140701200011.txt' is denied.
Basically i am using defaul NT service for SQL Agent
If I return the Average, Minimum, and Maximum values for the counter Physical Disk: Avg. Disk Queue Length, and those values are 10, 0, 87 respectively, which value do I use to compute the Avg. Disk Queue Length for a 4 disk array(RAID 10): Average, Minimum, or Maximum? The disk(lun) is on a SAN.
I want to write a query to generate a report. I have a date column which will be holding all the business dates. No dates of Saturday and Sunday are allowed. What I am looking for is, I want to get the result of every 5th business day of each month. A month could start with any day. I just want only the 5th business day.
View 9 Replies View RelatedI am trying to write a stored procedure that is an INSERT INTO <sql table> FROM <other sql tables> WHERE <where clause>.
I need to insert 3 columns from multiples SQL tables into one SQL table. Here is my code snippet:
ALTER PROCEDURE [dbo].[sp_insert_test]
@MID INT OUTPUT,
@CIDINT OUTPUT,
@MemberNVARCHAR OUTPUT
[Code] ....
i cannot pass any of the values to the tblVotings table and not sure how to enter the @MID, @CID and @Member to the INSERT INTO statement.
-- Initialize Control Mechanism
DECLARE@Drive TINYINT,
@SQL VARCHAR(100)
SET@Drive = 97
-- Setup Staging Area
DECLARE@Drives TABLE
(
Drive CHAR(1),
Info VARCHAR(80)
)
WHILE @Drive <= 122
BEGIN
SET@SQL = 'EXEC XP_CMDSHELL ''fsutil volume diskfree ' + CHAR(@Drive) + ':'''
INSERT@Drives
(
Info
)
EXEC(@SQL)
UPDATE@Drives
SETDrive = CHAR(@Drive)
WHEREDrive IS NULL
SET@Drive = @Drive + 1
END
-- Show the expected output
SELECTDrive,
SUM(CASE WHEN Info LIKE 'Total # of bytes : %' THEN CAST(REPLACE(SUBSTRING(Info, 32, 48), CHAR(13), '') AS BIGINT) ELSE CAST(0 AS BIGINT) END) AS TotalBytes,
SUM(CASE WHEN Info LIKE 'Total # of free bytes : %' THEN CAST(REPLACE(SUBSTRING(Info, 32, 48), CHAR(13), '') AS BIGINT) ELSE CAST(0 AS BIGINT) END) AS FreeBytes,
SUM(CASE WHEN Info LIKE 'Total # of avail free bytes : %' THEN CAST(REPLACE(SUBSTRING(Info, 32, 48), CHAR(13), '') AS BIGINT) ELSE CAST(0 AS BIGINT) END) AS AvailFreeBytes
FROM(
SELECTDrive,
Info
FROM@Drives
WHEREInfo LIKE 'Total # of %'
) AS d
GROUP BYDrive
ORDER BYDrive
E 12°55'05.25"
N 56°04'39.16"
Hello,
I am trying to setup a test cluster and am having an issue. When I try to create the resource of a physical disk it takes both the drive e: and drive q: and doesn't seperate them into two physical disks as resources. This means when I try to associate the quorum disk it links the to physcial disk resource of drive e and q. Then when I try to install SQL2k5 I get the warning about installing SQL on the quorum disk. Am I missing something? Is there a way to seperate e and q onto two physical disk resources so I can specifically associate the quorum to q and the sql to e or should I be setting the quorum disk to a majority node set? Thanks in advance.
John
Why I see absolutely no performance improvement when I spread my primary file group over 8 separate files on 8 separate disks, as opposed to having the primary file group all in one file on one disk.
I have set up 2 identical databases, one spread over 8 disks and one on one disk. Each database has a table called DATA and a column called VALUE. Value is NVARCHAR(200). I have filled each table up in both databases with 20,000 rows.
I then perform a select on each table in each database using CHECKPOINT and DBCC DROPCLEANBUFFERS to ensure I am reading from disk before each query and the execution times are identical in both databases.
I then ran the same queries against each database using a load testing tool and the batch requests per second on each DB is identical under load.
Surely the database with data spread over 8 disks should be FAR faster than the single file database as you have the combined reading power of 8 disks as opposed to 2??
Also, the same is happening for write speeds. When I create the data on both databases, the time it takes is identical on both.
BOL says it should be faster with multiple disks.
Just FYI this is on an Azure virtual machine and each disk is a locally redundant data disk that I have attached to the virtual machine.
Whether write speeds should increase with multiple disks or just read speeds?
I want to write sql query which runs in a background on cyclic basis. Basically i want to count the row entries of 1 table and store the data and the count in two distinct columns.
View 3 Replies View RelatedHow can i get the total number of each distinct value in the column and write it to another table e.g.
MyTable
Id Fruit
1 Apple
2 Banana
3 Apple
4 Watermelon
5 Banana
6 Watermelon
7 Apple
Result
Fruit Count
Apple 3
Banana 2
Watermelon 2
I can create a string into a local "@" variable. It can include a date/time, and text for my timing testing.
I need to be able to send that string to the results window where table output goes, rather than to the message window where a PRINT statement goes.
How do I do that?
What I really need is to find the entries that have the word LVAD but on either side there should be a space chartacters.In other words I don't want to see the following coming from the query "SILVADENE ([PHI] SULFADIAZINE)"How can we write this query to search only for any entry that has the word " LVAD " ?
Select top 100 * FROM tbl_abc
where
AIMS_Value like '%LVAD%'
Hello,
this is my configuration :
1) 3 disks in RAID5 that hold the SQL data
2) 1 disk in RAID0 that holds the only paging file.
What will happen to the SQL data (DB) when the disk that holds the paging file crashes?
Kindest regards,
Luc.
I am currently investigating aa high avg write time ms issue (145ms) which seems to be only occuring on the tempdb data files.I have followed the recommended setup of TEMPDB in that
1. Data files = number of physical cores
2. Data files and logfiles are on separate partitions away from the other databases.
3. Tempdb is presized and no incremental file increases look like they are happening with frequency.
We have sharepoint 2012 setup on other sql servers and with TEMPDB setup following the same guidelines, with far more Sharepoint activity on a similary specified hardware which is why its confusing.FileIO auditing on the partitions themselves shows that the FileIO is very fast on the partitions that the tempdb data file which leads me to beleive that Sharepoint may be the culprit perhaps due to excess use of tempdb with operations taking a long time to resolve.
How do I determine the read/write frequency on a database table? I am trying to do this on a 2012 and 2008 R2 servers.
View 2 Replies View RelatedI am testing out a blank database created over two physical files on two separate disks with one table called data which has one column called values nvarchar(max).
I filled the table up with a whole load of data and ran a select * against it. If I run Permon at the same time I can see that the read load has been spread over multiple disks as each of these disks is getting read from in parallel. If I create the same database on a single file and run the same select * again it takes much longer, proving that the read load has been distributed across multiple disks.
Now moving onto writes, this is where the confusion lies. I understand that SQL server fills files evenly until they need growing, after which it will then fill files individually until they are full in a round robin fashion unless you have trace 1117 turned on. What I don't understand is why the writes aren't distributed out whilst it is filling these file groups.
I ran an continual insert into my table with go 1000000 to monitor how the files are being filled up. I monitored where SQL server was physically placing the files as they were being inserted by running the following query:
;WITH CTE AS
(SELECT
sys.fn_PhysLocFormatter (%%physloc%%) col1,
RIGHT(LEFT(sys.fn_PhysLocFormatter (%%physloc%%),2),1) AS [Physical RID],
DATAID
[Code] ....
I could see that it would a thousand or so records into file 1, then a thousand or so into file 2, then a thousand or so into file 1 etc etc. In another words it would hit one disk, then another disk, then back to disk one to fill the file evenly. Is there any way to make SQL Server distribute the writes out in parallel so that both disks are writing in tandem?
By the looks of it, multiple disks only scale reads, as with writes only one disk is ever written to at once which is annoying. Any way to harness the write power of multiple disks?
How to write Stored Procedures to load the Data Model from OLTP to DWH ?
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