Getting Reliable Information About Cache Hit Ratio
May 5, 2004
Maybe I am just a lot better at this than I thought, but I figure that somewhere there is a mathematical rule that is being overlooked. When I run dbcc sqlperf (lrustats) on some of my production machines, I sometimes end up with a cache hit ratio (which is defined as a percentage, mind you) that is slightly over the limit:
Statistic Value
-------------------------------- ------------------------
Cache Hit Ratio 100.00898
Cache Flushes 0.0
Free Page Scan (Avg) 0.0
Free Page Scan (Max) 0.0
Min Free Buffers 331.0
Cache Size 4362.0
Free Buffers 9434.0
I suspect some counter somewhere is getting wrapped around its 4 byte limit. Is there any reliable source for getting statisics about SQL Server performance? Users tend be unreliable and say everything is slow.
View 2 Replies
ADVERTISEMENT
Mar 13, 2003
On Microsoft performance monitor, what is the difference between SQL Server Cache Manager: Cache Hit Ratio and SQL
Server Buffer Manager: Buffer Cache Hit Ratio? We have a production server where the buffer cache hit ratio is
consistently at 99%, which is normal. However, the cache hit ratio is 73%. What is the difference between the two
hit ratios, and why would we have such a significant difference between the two?
Any help or advice would be much appreciated.
View 5 Replies
View Related
Sep 18, 2000
I have been seeing this strange statistics in one of our servers. The cache hit ratio has gone beyond 100%, it is currently showing 124%. Has anyone seen this before.
Thanks
View 1 Replies
View Related
Mar 18, 2005
I have a large dell server with 4 processors, and 8 gig of memory on win 2000 advanced with sql 2000 enterprise edition running a 3rd party app. My cache hit ratio averages about 76%. I thought the gneral rule was if you get below 80% to add more memory. However my memory manager shows I am only using 71% of my memory and have a full gig available. I have the sql server set to use about 7.1 gig of the 8 gig on the server. My ? is if I am only using 71% of my memory, will will adding more memory actually help my cache hit ratio
View 5 Replies
View Related
Jul 23, 2005
HelloI am tring to figure out why our SQL server is a bit sluggish fromtime to time.It is running a dual XEON, with 2.5 GB RAM, and a fast SCSI I/O subsystem setup as follows.OS, mirrored 2 drivesSQL DATA 16 HDD RAID 10SQL LOG 4 HDD RAID 10SQL tempdb 4 HDD RAID 10OS = win 2003SQL = sql2000 standard editiondbcc showcontig shows me nothing special, it looks okI launch performacne monitor and add SQL server cache manager: hitratioand it is constantly at 7% and never changes up or down, it is justconstant.Can this be correct? and if so it sounds rather bad, we have ahandfull of large tables that are heavily used and enough RAM to holdthem all in RAM so I really do not understand why the cache hit ratiois not higher.Any hints would be greatrgdsMatt
View 9 Replies
View Related
Jan 2, 2004
Does anyone know how to measure the buffer cache hit ratio? I have been reading a lot about it but can't find this measurement in Performance Monitor.
Thanks
View 1 Replies
View Related
Jun 20, 2014
I'm putting together some monitor scripts, have buffer cache ratio etc etc but struggling to get an accurate script for the current procedure cache hit ratio...
View 1 Replies
View Related
Jul 16, 2015
What is better values for Buffer Cache Hot Ratio in SQL Server 2012. Is the values changed from 2008r2 to 2012?
View 2 Replies
View Related
Jun 19, 2008
I am wondering if 100% buffer cache hit ratio is considered not good in general?
Are there instances that it is actually bad and can contribute to server performance degradation?
Any thoughts on the topic most welcome :)
--------------------
keeping it simple...
View 11 Replies
View Related
Jul 23, 2005
This issue just happen recently. The buffer cache ratio went from > 90%to 50% and has slowly been climbing back up over 8 hours or so. Itscurrently @ 76%. Is this something I should take action on immediately?It seems to be coming back to normal...
View 1 Replies
View Related
Sep 1, 2006
HiI have trouble with MSSQL2000 SP4 (without any hotfixes). During last twoweeks it start works anormally. After last optimalization (about few monthsago) it works good (fast, without blocks). Its buffer cache hit ratio wasabout 99.7-99.8. Last day it starts work slow, there was many blocks anddedlocks. There are no any queries, jobs and applications was added. Nowbuffer cache hit ratio oscilate about 95-98. I try update statistics andreindex some hard used tables, but there is no effect or effect is weryshort (after few hours problem return).Mayby somene know what it could be?Is it possible to estimate how each table (using DBCC SHOW_STATISTICS orDBCC SHOWCONTIG or others) how the table affect on total buffer cache hitratio?Marek---www.programowanieobiektowe.pl
View 1 Replies
View Related
Sep 12, 2014
Our server administrator forwarded some messages from SCOM that indicate:
SQL DB Engine 2012 Page Life Expectancy and Buffer Cache Hit Ratio is too low
When I logged into the offending server, I could not find anything in the SQL Log File that indicates this.
I was wondering how did SCOM identify this issue - where in SQL Server would this have been reported to SCOM?
View 3 Replies
View Related
Aug 18, 2015
What is the difference between CleanExpiredCache and FlushReportFromCache Do we need to run both the SPs to clear all the SSRS reporting cache? Is it possible to clean all the Cache information and retain the logs? If yes how we can do so. Is it by deleting the REportServerTempDB.dbo.ExecutionCache table work in achieving this?
View 8 Replies
View Related
Dec 27, 2007
Im getting this error when trying to set up a cache dependency...are there any special permissions etc?From CS:SqlCacheDependency dep = new SqlCacheDependency("MySite-Cache", "Products");Cache.Insert("Products", de.GetAllProductsList(), dep); From connectionStrings.config:<add name="SiteDB" connectionString="Data Source=localhost,[port]SQLEXPRESS;Integrated Security=true;User Instance=true; AttachDBFileName=|DataDirectory|ASPNETDB.MDF" providerName="System.Data.SqlClient" />Also tried this using my machinename<add name="SiteDB" connectionString="Data
Source=<machinename>,[port]SQLEXPRESS;Integrated Security=true;User
Instance=true; AttachDBFileName=|DataDirectory|ASPNETDB.MDF"
providerName="System.Data.SqlClient" /> From web.config: <caching> <sqlCacheDependency enabled="true" pollTime="10000"> <databases> <add name="MySite-Cache" connectionStringName="SiteDB" pollTime="2000"/> </databases> </sqlCacheDependency> </caching> EDIT: So making progress I can't seem to get the table registered for cache dependency:The sample i have says"aspnet_regsql.exe -E -S .SqlExpress -d aspnetdb -t Customers -et"and the command line response is "Enabling the table for SQL cache dependency..An error has happened. Details of the exception:The table 'Customers' cannot be found in the database."Where does this "Customers" table come from? There is obviously not an application specific "Customers" table in aspnetdb I'm confused probably more by the example than anything....
View 3 Replies
View Related
May 31, 2007
Is there a way to drop clean buffers at the database level instead of the server/instance level like the undocumented €œDBCC FLUSHPROCINDB (@dbid)€??
Is there a workaround for €œdbo€? to be able to flush procedure and data cache without being elevated to €œsysadmin€? server role?
PS: I am aware of the sp_recompile option that can be used to invalidate cached execution plans.
Thx.
View 1 Replies
View Related
Feb 15, 2008
Hi guys,
I am looking at the plan caches/cached pages from the perspective of
sys.dm_os_memory_cache_counters and sql serverlan Cache - Cache Pages
For the first one I am using
select (sum(single_pages_kb) + sum(multi_pages_kb) )
from sys.dm_os_memory_cache_counters
where type = 'CACHESTORE_SQLCP' or type = 'CACHESTORE_OBJCP'
a slight change from a query in
http://blogs.msdn.com/sqlprogrammability/
For the second just perfmon.
The first one gives me a count of about 670,000 pages only for the object and query cache and the second one gives me a total of about 100,000 pages for five type of caches including object and query.
If I am using the query from http://blogs.msdn.com/sqlprogrammability/ to determin the plan cache size
select (sum(single_pages_kb) + sum(multi_pages_kb) ) * 8 / (1024.0 * 1024.0) as plan_cache_in_GB
from sys.dm_os_memory_cache_counters
where type = 'CACHESTORE_SQLCP' or type = 'CACHESTORE_OBJCP'
it gives me about 5 GB when in fact my SQL Server it can access only max 2GB with Total and Target Server Memory at about 1.5 GB.
Does anyone have any idea what is going on?
View 2 Replies
View Related
Jul 20, 2005
SQL 7.0I have a form in ASP.NET and I want to write the values to the SQLServer tables.The tables are Customer and Address tables.There will be an insert into the Customer table, and I need to use theIdentity of this inserted record for the Foreign Key in the Addresstable insert.For exampleINSERT INTO Customer (CustomerName)VALUES (@CustomerName)Select @@identity as CustomerIDINSERT INTO Address (Address, CustomerID)VALUES (@Address, CustomerID)My question is this. If I put this into a single stored procedure canI absolutely GUARANTEE that the @@identity value will be from theCustomer table insert, or could it feasibly be from another, as itwere, colliding operation?TIAEdward--The reading group's reading group:http://www.bookgroup.org.uk
View 2 Replies
View Related
Jan 16, 2008
How reliable the SQL Compact 3.5 is?
What I need is to make sure that in case if my Windows CE based device lost power supply my SQL Compact 3.5 database will not be corrupted and I can read data from it.
Has anybody any experience in this area?
This is critical requirement for our project and I want to know it is feasible or not.
View 1 Replies
View Related
Mar 5, 2007
Hi..
I have a SQL Server 2005 Database .. I develop for the customers a C# Application , that sends some specific Information to my central Database.
If I would create a connection over tcp/IP (in order to send data to central database) like
sqlconnection1.ConnectionString = "Data Source=192.XXX.Y.ZZ,1433;Initial Catalog=Muster;Integrated Security=True";
it would not be reliable. How can we make that safe?
Thanks...
View 4 Replies
View Related
Nov 22, 2002
I have set up two Maintenance Plans to do daily backups overnight for our two DBs that are on our SQL server.
As a separate strategy we want to have a second backup done nightly that would involve
#1 detach the db(s)
#2 copy the mdf(s) and ldf(s) to L:xxx
#3 attach the db(s) again
#4 zip up the db(s)
#5 copy the files to a different server for storage.
I created #1, and #3 in query analyzer and saved the script.
I want the process to run at say 2AM and don't know how to schedule them to run - that is #1 ... #2 ... #3. Anyone have sample scripts for this kind of a backup strategy?
This seems like a very simple process especially for a restore and especially since there would not be any trasaction logs involved. This way if we had a KRASH we could take the backup from the separate server and install it on a warm SQL backup server.
Apart from the new servers name then what other steps would I need to cover to get the apps up and running in the quickest time. The app software runs as a client install - Access 97DB] I'm especially curious if I need to have more than a fresh MS2000 SQL server install.
I'm know I'm asking a lot for a first timer.
It seems we want to handle disaster recovery BEFORE we even have our first system crash.
many thanks
View 11 Replies
View Related
Dec 29, 2007
I have a process that restores a backup from a primary server to a backup server daily. When doing the restore, sometime it fails (for various reasons).
I have coded a job to Set offline, set online, an then do the restore:
RESTORE DATABASE [xxx] FROM DISK = N'D:Backup Stagingxxx.bak' WITH FILE = 1, NOUNLOAD, REPLACE, STATS = 10
Sometimes it fails to bring back online, other errors as well. Is there a reliable method of doing this?
View 1 Replies
View Related
Jul 5, 2007
Hi,
For this scenario, what is the best method of exporting data to sql 2005.
I want to export data from desktop app across internet to sql which can do on a row by row basis, but this is very slow and if the connection goes down halfway then pretty much buggered.
What is the best, reliable and fastest way to copy data across internet (several thousand rows), I have read about Bulk Insert etc... but also how would get around an upload and crashes half way, is there a way of uploading and until the whole upload goes through then the data is inserted into the database.
Would appreciate any guidance.
Richard
View 3 Replies
View Related
Mar 14, 2008
I have been tring to get this one line figured out for a few days now.
'Job2 Info
Dim selectSQL2 As StringselectSQL2 = "SELECT * FROM '" & CompanyKey & "'" '<<-------HERE
Dim cmd2 As New SqlCommand(selectSQL2, con)
'Job2 Select
Try
con.Open()
reader = cmd2.ExecuteReader()
(I have the full code below.) So here is the problem, this code is not populating the datagrid. There is data in the table I am selecting from. When I log in, my CompanyKey value displays in the label as "21". When I take out the "CompanyKey" variable, and just type in 21, the grid is populated. It is confusing the heck out of me. I have tried it this way:
selectSQL2 = "SELECT * FROM [" & CompanyKey & "]"
-and this way:
selectSQL2 = "SELECT * FROM & CompanyKey
and all the other ways I could think of. I researched it and can just not get it to work any way I do it. Any suggestions? Full code below:
____________________________________
Imports System.DataImports System.Data.CommonImports System.Data.SqlClient
Partial Class _Default
Inherits System.Web.UI.PageProtected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'Database ConnectionDim con As New SqlConnection("Data Source = .SQLExpress;integrated security=true;attachdbfilename=|DataDirectory|ASPNETDB.mdf;user instance=true")
'Job1(Info)Dim currentUserID
currentUserID = Context.User.Identity.Name.ToString()
Label1.Text = currentUserID
Dim selectSQL1 As StringselectSQL1 = "SELECT companyKey FROM Company WHERE UserID = ('" + currentUserID + "')"
Dim cmd1 As New SqlCommand(selectSQL1, con) Dim reader As SqlDataReader
Dim CompanyKey
'Job1 Select
Try
con.Open()
reader = cmd1.ExecuteReader()Do While reader.Read()
CompanyKey = reader("CompanyKey").ToString()
Loop
reader.Close()Catch err As Exception
ReaderError.Text = "Error selecting record."
ReaderError.Text &= err.Message
Finally
con.Close()
End Try
'Job2 Info
Dim selectSQL2 As StringselectSQL2 = "SELECT * FROM [" & CompanyKey & "]"
Dim cmd2 As New SqlCommand(selectSQL2, con)
'Job2 Select
Try
con.Open()
reader = cmd2.ExecuteReader()
GridView1.DataSource = reader
GridView1.DataBind()
reader.Close()Catch err As Exception
ReaderError.Text = "Error selecting record."
ReaderError.Text &= err.Message
Finally
ReaderResults.Text = CompanyKey
con.Close()End TryEnd Sub
End Class
View 4 Replies
View Related
Oct 24, 2007
I posted a more detailed technical question a couple of weeks ago
with Subject = "Compact Edition 2005 Subscribers - Merge Agent failed after detecting that retention-based cleanup has deleted metadata"
But I got no replies.
Now my question is simpler: Is SQL Server 2005 Merge Replication reliable with Compact Edition subscribers on WindowsXP tablets?
We deleted all users' local databases a couple of weeks ago, and republished two publications with retention = 60 days.
Now we have at least one user who can't sync with the server, and replication monitor shows the error below.
But if she e-mails her sdf file to a support person, they can successfully sync her database.
We're sure that it's not a permissions issue, which is a normal suspicion when one user can perform a task that another can not.
It doesn't seem like a retention problem, because she's well inside the retention period.
She can successfully sync with the publication with upload/download tablers, but not with the publication with download only tables. Both publications were created on the same day, by the same DBA, with nearly identical properties.
This problem user has operated in the past with no problem, and she's configured identically to all of the others. It just seems like random flakyness with merge replication for Compact Edition subscribers.
I feel stupid saying that, because it sounds like I believe in a magical ghost in the machine. So my question is - IS MERGE REPLICATION A LITTLE BIT FLAKY FOR COMPACT EDITION SUBSCRIBERS ON XP MACHINES?
We've applied SP2 to the server, but no subsequent HotFixes.
We're trying to sell users and management on developing a larger occasionally connected system with the same replication scheme, so we need to know if it deserves our confidence.
Error messages:
The Merge Agent failed after detecting that retention-based metadata cleanup has deleted metadata at the Publisher for changes not yet sent to the Subscriber. You must reinitialize the subscription (without upload). (Source: MSSQL_REPL, Error number: MSSQL_REPL-2147199402)
Get help: http://help/MSSQL_REPL-2147199402
View 2 Replies
View Related
May 21, 2008
Hello,
I have a calculated member that is a ratio calculation. It works fine but I would like that the value for the "All" member to be the sum of the children.
So I have the following MDX where the calculated member [Dim Group Rubric].[Group Rubric Description].[BO + ADM Cost] does not give me good results for the "All" member:
WITH
MEMBER [TOTAL YEAR CONTRACT] AS sum({[Total Year]},[Dim Contract].[Contract Number].[563131])
MEMBER [TOTAL YEAR BU] AS sum ([Total Year])
MEMBER [Dim Group Rubric].[Group Rubric Description].[TOTAL BU PVN] as
([Dim Group Rubric].[Group Rubric Description].[PVN], [TOTAL YEAR BU])
MEMBER [Dim Group Rubric].[Group Rubric Description].[TOTAL BU BO + ADM] as
([Dim Group Rubric].[Group Rubric Description].[BO + ADM], [TOTAL YEAR BU])
MEMBER [Dim Group Rubric].[Group Rubric Description].[BO + ADM Cost] as
([Dim Group Rubric].[Group Rubric Description].[PVN], [TOTAL YEAR CONTRACT])
/ ([Dim Group Rubric].[Group Rubric Description].[TOTAL BU PVN], [TOTAL YEAR BU])
* ([Dim Group Rubric].[Group Rubric Description].[TOTAL BU BO + ADM], [TOTAL YEAR BU])
SELECT
NON EMPTY {[TOTAL YEAR CONTRACT],[TOTAL YEAR BU]}
ON 0,
{[Dim Group Rubric].[Group Rubric Description].[BO + ADM Cost]}
*
UNION(
[Dim BV Organisation Finance].[Business Unit].[All]
,FILTER(
[Dim BV Organisation Finance].[Business Unit].children
,[Dim BV Organisation Finance].[Business Unit Code].currentmember.name
= '071MIND1'
)
,FILTER(
[Dim BV Organisation Finance].[Business Unit].children
,[Dim BV Organisation Finance].[Business Unit Code].currentmember.name
<> '071MIND1'
)
)
ON 1
FROM (SELECT ([Dim Year].[Year].&[2008]) ON 0
FROM (SELECT ({[Dim BV Organisation Finance].[Business Unit Code].[071MIND1]
,[Dim BV Organisation Finance].[Business Unit Code].[071DIDD1]}) ON 0
FROM [BV Contract Margin DW]))
When I launch this query I obtain:
TOTAL YEAR BU
BO + ADM Cost All - 45013 (I would like to obtain here - 90651)
BO + ADM Cost 071MIND1 - 35680
BO + ADM Cost 071DIDD1 - 54971
Please do you know what should be changed in this query to obtain the good results?
Thanks.
Guillaume
View 3 Replies
View Related
Nov 14, 2007
I have to get the ratio like A:B with two calculated columns. A and B both are the counts of the rows.
Please help me with this, it's really urgent!
View 2 Replies
View Related
Oct 16, 2007
Can anyone pls help me to solve my problem in SSRS. Also I wanted to plot the 'Ratio' in to a chart against the 'Year'.
The scenario is:
Year Amount_A Amount_B Ratio(Amount_A/Amount_B)
05 x y x/y
06 a b a/b
07 m n m/n
Its very needy.
View 9 Replies
View Related
Oct 28, 2015
How do I author a SQL Query which meets the following requirement: Display a ratio of (instances where status is a success)/(instances where status is a success or instance is a failure). The below syntax is incorrect. However, I hope to beter explain what I am trying to accomplish using the incorrect SQL query below.
SELECT SUM(Case When Status = "SUCCESS")/SUM( Case When Status = "FALLBACK")
FROM ruleResults;
View 2 Replies
View Related
Dec 1, 2014
I am doing some work in microstrategy reports and using SQL data cube. I am creating a summary report (Counting on Unique ID) in MS where when I put in a particular attribute/column from cube it splits the data count down into 2 separate values that I have defined in the select case statement of the SQL query.
I want to work out a ratio of the count unique ID between these two values but can't do this in MS report as it is not a physical column but summary split of data.Is there a way I can do this in SQL? My summary looks something like this:
N E
====================== =========================
**Y** N **Y** N
========= ========== ========= =========
570 140 89 56
Where the Y/N field is the one I have split down against the N/E column. I want to work out ratio between the 2 "Y" fields but in SQL. Here is a SQL example snapshot of my data:
Unique_ID New/Existing Application Attend_Interview
========= ======================== ================
12554445 E Y
65766879 N N
53375654 N Y
44323224 E N
93656786 E Y
wondering if I might be able to do a procedure or similar or something more dynamic in SQL query?
View 1 Replies
View Related
Sep 26, 2000
Hi,
In m*y SQL server 7.0,
when using Performance, I see in graph: Buffer Catche Hit Ratio Counter
(SQLServer Buffer Manager objects)always is maximum (100). What does this mean ? What's the Buffer Catche Hit Ratio?
How do I configure SQL server to performance?
Thanks in advance.
View 1 Replies
View Related
Oct 30, 2015
I'm collecting performance data via DMV to check the buffer hit ratio on several servers. Sometimes I get values high above 100% hit Ratio.
Example (50050%):
SQLServer:Buffer Manager:Buffer cache hit ratio 2002
SQLServer:Buffer Manager:Buffer cache hit ratio base 4
View 11 Replies
View Related
Aug 31, 2015
I am checking some ratio numbers for our system engineers, those are
Read/write ratio?
Random/sequential ratio?
Read/write block size?
For Read/write ratio, I am using below query,
SELECT
m.type_desc
, CEILING(sum(num_of_bytes_read*1.0) / (sum(num_of_bytes_read*1.0) + sum(num_of_bytes_written*1.0)) * 100) AS 'Read %'
, CAST((sum(v.size_on_disk_bytes) / 1024.0 / 1024 / 1024) AS MONEY) AS 'FileSizeGB'
[Code] ....
Random/sequential ratio, I googled but cannot find a similar query to get the result?
View 1 Replies
View Related
Nov 20, 2015
Sample Query :
SELECT 'A' [Type], 1 AS [NUMERATOR]Â Â Â Â , 2 AS [DENOMINATOR]
UNION ALL
SELECT 'B' [Type], 2 AS [NUMERATOR]Â Â Â Â , 4 AS [DENOMINATOR]
UNION ALL
SELECT 'C' [Type], 3 AS [NUMERATOR]    , 6 AS [DENOMINATOR]
[Code] ...
I need to show the ratios beside each bar (shown in red)Â as shown in the above diagram.
View 2 Replies
View Related
