SQL Server 2014 :: Profiler Reads Column Incorrect For Parallel Plans?
Aug 19, 2015
I often use profiler as one tool to identify bad plans. The reads column gives me a good indication of excessive IO to dig into and correct if necessary. I often use it with Showplan so I can see what a query does, replicate it and fix it.
However I have just lost some faith in it. I am looking at a poorly performing query joining five tables. A parallel plan has been generated and one table is being scanned (in parallel) due to a missing index. This table had in excess of 4 million rows in it. The rest hitd indexes well. However the entire query generates ONLY 12 READS.
Once corrected, a single processor plan is used. This looks really efficient and uses 120 reads. That looks the right figure to me.
Clearly 12 reads is wrong. Does the profiler only display one thread of a parallel plan perhaps? Or something else?
View 1 Replies
ADVERTISEMENT
Aug 19, 2015
Is the SQL Server Profiler Reads Column Incorrect For Parallel Plans?
I often use profiler as one tool to identify bad plans. The reads column gives me a good indication of excessive IO to dig into and correct if necessary. I often use it with Showplan so I can see what a query does, replicate it and fix it.
However I have just lost some faith in it. I am looking at a poorly performing query joining five tables. A parallel plan has been generated and one table is being scanned (in parallel) due to a missing index. This table had in excess of 4 million rows in it. The rest hitd indexes well. However the entire query generates ONLY 12 READS.
Once corrected, a single processor plan is used. This looks really efficient and uses 120 reads. That looks the right figure to me.
Does the profiler only display one thread of a parallel plan perhaps? Or something else?
View 9 Replies
View Related
Jul 27, 2007
Hi,
Can any of can explain, what the "Reads" column in Profiler exactly mean ? I'm not comfortable with the explanation given in BOL.
"The number of read operations on the logical disk that are performed by the server on behalf of the event. These read operations include all reads from tables and buffers during the statement's execution"
For the same procedure with same parameters, if the server is not loaded much, the Reads are in a few hundreds, but when there are more than 1000 concurrent users, why it is going to millions ? What other parameters affecting this reads ? And how can I reduce it ?
Environment: SQL Server 2005 64-bit Enterprise Edition on Windows Server 2003 R2 Server x64 Enterprise Edition SP2
Thanks in Advance.
Regards
Babu
View 4 Replies
View Related
Jul 17, 2015
I have inherited a database that is over-indexed, i.e. there are sometimes 10-20 indexes on a table. The performance is at times not great due to blocking from long running queries. I want to clean up the indexes as a starting point.
Through a query I found some time ago on the SQLCat blog I have discovered a large number of indexes in the database that have a huge disparity between reads and writes. The range of difference is sometimes almost 2 million more writes than reads. Should I just drop the indexes that have say, more than 100,000 more writes than reads and then see what the Missing Index DMVs tell me after a few days of running without those indexes?
In some cases there are a few hundred thousand reads but maybe a million writes on the index. Thus, there are a fair number of reads happening, just not in comparison to the number of writes. In some cases there are almost no reads and a million or more writes. I am obviously dropping those indexes. I just am not sure what to do about the indexes that do have a fair number of reads.
View 9 Replies
View Related
Jul 23, 2005
I am running a profiler trace against a database and noticed that thereads column always shows 0. When running the same trace againstanother machine I get back values in the reads column. I took a querythat profiler reported as having 0 reads and ran in in query analyzerwtih STATISTICS IO on and confirmed that there are in fact reads:Table 'tt_cawardalloc'. Scan count 1, logical reads 8, physical reads0, read-ahead reads 1.Table 'tt_clineitem'. Scan count 10, logical reads 125208, physicalreads 1540, read-ahead reads 2995.Table 'tt_contractitem'. Scan count 32, logical reads 676, physicalreads 0, read-ahead reads 0.Table 'tt_contract2'. Scan count 3, logical reads 121, physical reads4, read-ahead reads 0.I am on SQL 2000 sp3a. Any help appreciated.Thanks!
View 8 Replies
View Related
Apr 17, 2007
I'm running the same query on two different PCs and tracing results in Profiler on my PC. When executing the query on PC1 - the total number of reads is 200000. When executing the same query on PC2 - the toal number of reads is 13000. It is almost 15 times more reads when executing query on PC2. The executed query is same on PC1 and PC2. Any reason for this?
I'm trying to analyse that query and reduce the number of logical reads as it's is too high but then I get completly different result on different PC.
Thanks.
View 5 Replies
View Related
Jun 2, 2008
I ran Sql profiler and got the following results for a stored procedure
CPU of 1078;
Reads of 125464
writes of 0
Duration of 1882
how do i interpret the above results.
also what CPU and Duration is considered high and indicating a poor performing query.
I am using SQL Server 2005. Thanks
View 4 Replies
View Related
Apr 17, 2007
I'm using an application that produce 48000000 reads for one stored procedure and 170 seconds to complete. The same procedure when executed in SQL Analyzer takes only one seconds and 10000 reads.
What is happening here? Where should I look to solve this problem?
Thanks
View 1 Replies
View Related
Jun 2, 2014
I am writing a performance baseline test.
The first test writes 5000000 rows in one table. I realise this is not representative OLTP behaviour, but it worked me to start interpreting performance counters and to test several setups to be discussed with our server, storage and network administrators. This way we have been able to compare the results of different hard disks, Lun vs vmdk, 1GB vs 10GB network, AMD vs Intel, etc. This way I can also compare several SQL setups (recovery model, max memory config, ...)
The screenshot shows the results of 2 runs on the same server : Win2012R2, SQL2014, 16GB RAM.
In test 1 min/max server memory was set to 9215MB/10751MB
In test 2 min/max server memory was set to 13311MB/14847MB
The script assures the number of bytes inserted in the nvarchar columns is always the same.
This explains why the number of pages and the number of MB in the table are the same at the end of the 2 tests (column 5 and 6)
Since ca 13GB has to be written, the results of test 1 show the lead time is increasing once more than 10GB has been inserted (column 8 and 9) In addition you can see at that moment
- buffer cache hit ratio is decreasing
- page life expectance becomes "terrible"
- free list stall/sec increases
- lazy writes/sec increases
- readlatency increases (write latency does not)
In test 2 (id 3 in column 1 in the screenshot) those counters are not really influenced (since the 5000000 rows can all be stored in memory).
Now what I do not understand is :
Why the number of pages read (instance level) as well as the number of bytes read and the number of reads (databaselevel) is increasing extremely during run 1.
I expected to see serious impact on write behavior, since SQL server is forced to start flushing dirty pages once memory is filled. Well actually you can see here the number of writes (not the the number of bytes written) starts to increase faster in test 1 after 4000000 rows, but there's no real impact on write latency.
Finally I want to notice
- I'm the only user on this machine
- the table has a clustered index on a identity column
- there are no foreign key constraints
- inserts are executed using a loop, not one big transaction
- to monitor progress and behaviour/impact, each 10.000 loops the counters are stored using dmv queries
So I wonder why SQL Server starts to execute so many reads in test 1.
View 4 Replies
View Related
Aug 11, 2015
In SQL 2008 R2, if we clone an environment including SQL server, the maintenance plans retain a connection string to the source/original server they got cloned from and are not editable. But, I was able to use a work around by editing them in BIDS and saving them back on the server. But now with 2014, I am facing two issues:
1.I still can edit the package to correct the server connection, with SSDT; but the option to save back to the server is not available any longer!
2.I used to be able to see all my plans under SSIS in 2008 R2 but not in 2014 now. Although, they are listed in SSMS!
View 1 Replies
View Related
Jun 19, 2015
How to run the profiler on always on read only database to troubleshoot an ssrs issue ?
View 0 Replies
View Related
May 14, 2015
I need to do testing on capturing connection coming from outside using Profiler. Basically I need to do something from other SQL servers connecting to this SQL server and test if it is captured by profiler.
View 4 Replies
View Related
Nov 30, 2006
I've been looking around for some kind of known issue or something, but can't find anything. Here's what I'm experiencing:
I have a table with about 50,000 rows. I open several connections and use a command to ExecuteResultSet against each command, with CommandType.TableDirect, CommandText set to the name of the table, and IndexName set to various indexes. In the end, I have several SqlCeResultSet instances which are then maintained for the life of the AppDomain.
In a loop, I call SqlCeResultSet.Read() on one of the instances, and if it returns false, I call SqlCeResultSet.ReadFirst() - essentially creating a circular pass through the result set.
In a Visual Studio debug session, this approach goes swimmingly for a short time, and then after a successful Read(), I'm pegged with an InvalidOperationException (text: "No data exists for the row/column") for a column which was succesfully read on the previous Read(). If, in the immediate window, I call SqlCeResultSet.Read() again on the result set instance, the Get___ methods work as they had been in the previous reads.
It seems like the internal state of the ResultSet is getting corrupted somehow, but it is opaque to me. Any insights on why this suddenly throws this exception?
View 8 Replies
View Related
Oct 29, 2001
I ran this query against the pubs database and it runs successfully
ALTER TABLE publishers ALTER COLUMN state CHAR(25)
I change the table & field names for my db as follows:
ALTER TABLE customquery ALTER COLUMN toclause CHAR(25)
and run against my database and I get the following error - Incorrect syntax near 'COLUMN'.
My column name is correct - I don't know why it would run fine against pubs, but not my db. I do not have quoted identifiers turned on. I have tried using [] around my column name [toclause], but that didn't change anything. Any help would be appreciated.
Thanks.
View 1 Replies
View Related
Oct 9, 2014
I have the following table
DECLARE @TABLE1 TABLE (D_ID int, C_ID int, C_HIST_ID int)
INSERT INTO @TABLE1
VALUES(1000016,71,77),
(1000017,71,547),
(1000017,71,553),
(1000017,71,564),
(1000013,71,565),
(1000017,71,3329),
(1000017,71,3330)
SELECT * FROM @TABLE1 ORDER BY C_HIST_ID
D_ID C_IDC_HIST_ID
10000167177
100001771547
100001771553
100001771564
100001371565
1000017713329
1000017713330
I was able to get the following result
SELECT D_ID,C_ID,C_HIST_ID
FROM @TABLE1 ACH
WHERE ACH.C_ID= 71
AND ACH.C_HIST_ID IN (SELECT MAX(ACH1.C_HIST_ID) FROM @TABLE1 ACH1
WHERE ACH1.C_ID = ACH.C_ID
AND ACH.D_ID = ACH1.D_ID )
ORDER BY C_HIST_ID
D_ID C_IDC_HIST_ID
10000167177
100001371565
1000017713330
But the result I need is
D_ID C_IDC_HIST_ID
10000167177
100001771564
100001371565
1000017713330
C_HIST_ID = 564, which I'm unable to get it through my query...
View 4 Replies
View Related
Apr 20, 2015
I want to set a default value to a column while adding it.
Create table test(id int )
insert into Test values(123)
alter table test add column2 int default(0)
In the above query I have set the default value, but it will not set the default value to the already inserted columns.
So how to set a default value for the already inserted rows, while adding a new column to it ?
View 6 Replies
View Related
Jan 8, 2014
I have data like this in the table :
IntRecpieID strName intMealtypeID Total
100 ‘A’ 1 20
101 'B' 2 30
100 'A' 3 40
Desired Output required:
IntRecpieID StrName 1 2 3
100 'A' 20 Null 40
101 'B' Null 30 Null
View 5 Replies
View Related
Aug 13, 2015
How do I append an accumulating number to duplicates in a column? I would prefer to update the table
for example
Name
John
John
Tom
Bob
Bob
Bob
Mike
to look like
Name
John
John1
Tom
Bob
Bob1
Bob2
Mike
View 1 Replies
View Related
Aug 24, 2015
I am new in SQL Server, What to check ,what action do i need to take while adding a new column to a table.
View 5 Replies
View Related
Sep 18, 2015
I have a table with some rows and columns what i want is i want to Show sum of particular column in the last row. This is my code.
SELECT DISTINCT Cluster.ClusterName, Gruppe.GruppeName, Arbeitspaket.ArbeitspaketName, BMWProjekt, AnzahlAP, Abgerechnet, InBearbeitung, Billanz FROM Bestellung
INNER JOIN Cluster ON Bestellung.Cluster = Cluster.rowid
INNER JOIN Arbeitspaket ON Bestellung.Arbeitspaket = Arbeitspaket.rowid
INNER JOIN Gruppe ON Bestellung.Gruppe = Gruppe.rowid
WHERE Projekt ="EA-284-Nxx" AND AnzahlAP <> 0 AND Abgerechnet is 1 AND InBearbeitung is NULL AND Billanz is NULL;
View 4 Replies
View Related
Oct 26, 2015
I've data as below
account period01 period02 period03 period04
1111 null null null null
1112 782 null null null
1113 null null null 345
1114 765 882 67 321
What I want to achieve is to get values from period1 till period04 and used the lasted value to code the value of accoutperiod, if value is from period1 then code it as 01, period2 as 02, period03 as 03 and period04 as 04. So the output should be like this
account period01 period02 period03 period04 accoutPeriod
1111 null null null null null
1112 782 null null null 01
1113 null null null 345 04
1114 765 882 67 321 04
View 2 Replies
View Related
Jul 12, 2007
Hi Experts,
We have a VLDB ( few table with above 200 million records ). This database is used for performance testing by simulating for 150 users and executing all necessary functional flows.
When I examined the profiler results , I could see some very high values as shown below in the duration column for many events.
1521729
3462142
1624325
3211255
1248276
3903998
Does it mean that that SP or the T-Sql statement is taking this much time in milliseconds to execute and give the output ?
Any help would be greatly appreciated.
Thanks & Regards,
DBLearner
View 1 Replies
View Related
Jun 25, 2014
I have a database it is 50 gb with hundreds of columns. I would like to choose a certain column and convert the data in it to .csv or excel file. How can I do that I am very new to MSSQL...
View 1 Replies
View Related
Sep 11, 2014
I want to fetch max of Field2 if duplicate records in Field1 and rest of the values of field1 , below is the sample format.
Field1 Field2 Field3 Field4
32 375 abc-xyz A
32 379 xyz-efg A
55 405 abc-xyz B
55 407 xyz-efg B
132 908 abc-xyz C
132 999 xyz-efg C
152 800 abc-xyz D
152 850 xyz-efg D
155 900 abc-xyz E
156 925 abc-xyz F
157 935 abc-xyz G
View 2 Replies
View Related
Feb 13, 2015
I am trying to import 1 spreadsheet to a database table. I am using SSMS export import wizard to import spreadsheet. My goal is to import whole spreadsheet in one single column.
View 7 Replies
View Related
Sep 9, 2015
I have huge export files in a DB and i need to check if there are any datasets that have the same value in the first column, but a different in another one, via a query of course.
Like this:
ID IS NULL
1 1
2 1
3 0
1 0
The expected ID i get as a result of my query should be 1 in this case.
View 6 Replies
View Related
Feb 13, 2014
We have a table with 2 columns 'OrderNo' and 'Amount' as below
ORDERNO | AMOUNT
1D1ZX000 | 9262.5
1D1ZX001 | 9000.0
1D1ZX001 | 9000.0
1D1ZX002 | 10000
1D1ZX003 | 1000
1D1ZX003 | 200.50
1D1ZX003 | 100.50
1D1ZX004 | 500.0
1D1ZX004 | 1000
1D1ZX004 | 2000
1D1ZX004 | 1000
as per my client requirement we need subtotal of 'Amount' group by 'OrderNo'. column so am writing a select statement with WHERE condition and I would like to have another column called SUBTOTAL in the result set (select statement result) with subtotals for that order Number as below
ORDERNO | AMOUNT | SubTotal
1D1ZX000 | 9262.5 | 9262.5
1D1ZX001 | 9000.0 | 18000
1D1ZX001 | 9000.0 | 18000
1D1ZX002 | 10000 | 10000
1D1ZX003 | 1000.0 | 3001
1D1ZX003 | 2000.5 | 3001
1D1ZX003 | 1000.5 | 3001
1D1ZX004 | 500.00 | 4500
1D1ZX004 | 1000.0 | 4500
1D1ZX004 | 2000.0 | 4500
1D1ZX004 | 1000.0 | 4500
View 7 Replies
View Related
Jul 1, 2014
I have the following SQL which i want to convert to a stored procedure having dynamic SQL to generate column numbers (1 to 52) for Sale_Week. Also, I want to call this stored procedure from Excel using VBA, passing 2 parameters to stored procedure in SQL Server
e.g,
DECLARE @KPI nvarchar(MAX) = 'Sales Value with Innovation' DECLARE @Country nvarchar(MAX) = 'UK'
I want to grab the resultant pivoted table back into excel. how to do it?
USE [Database_ABC]
GO
DECLARE @KPI nvarchar(MAX) = 'Sales Value with Innovation'
DECLARE @Country nvarchar(MAX) = 'UK'
SELECT [sCHAR],[sCOUNTRY],[Category],[Manufacturer],[Brand],[Description],[1],[2],
[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18],[19],[20],
[Code] ....
View 9 Replies
View Related
Dec 18, 2014
I am looking for SQL query which uses 2 tables CASH and BALANCE.
eg: Need Tablename, ColumsList and data in the results set.
eg: 10 rows shown below and ordered based on Acct_number
Row1,CASH,ACCT_NUMBER,AMOUNT,DEBIT_CREDIT_FLAG,ENTITY,BUSINESS_DATE,CURRENCY,REFERENCE,TRADE_TYPE,SUB ACC CODE
Row2,BALANCE,ACCT_NUMBER,OPENING_BALANCE,CLOSING_BALANCE,CLOSING_BAL_DEBIT_CREDIT_FLAG,BUSINESS_DATE,CURRENCY
Row3,CASH,10,500,CR,ABC,12/12/2014,USD,INTL,,US05
Row4,CASH,10,1000,DR,DEF,12/12/2014,USD,DOM,,US07
Row5,CASH,10,75,DR,XYZ,12/12/2014,USD,DOM,,US05
Row6,BALANCE,10,500,750,DR,12/12/2014,USD
Row7,CASH,20,500,CR,ABC,12/12/2014,USD,INTL,,US05
Row8,CASH,20,1000,DR,DEF,12/12/2014,USD,DOM,,US07
Row9,CASH,20,75,DR,XYZ,12/12/2014,USD,DOM,,US05
Row10,BALANCE,20,500,750,DR,12/12/2014,USD
View 7 Replies
View Related
Feb 24, 2015
I have the following 2 Query's - case when Table has no Identity Column and other with identity Column . I am planning to make it to single Query .
Query 1:
SELECT @ColumnNamesWhenNoIdentity = COALESCE(@ColumnNamesWhenNoIdentity + ',', '') + Name +'= SOURCE.'+Name
FROM sys.columns WITH(NOLOCK) WHERE object_id =
(
SELECT sys.objects.object_id
FROM sys.objects WITH(NOLOCK)
INNER JOIN sys.schemas WITH(NOLOCK) ON sys.objects.schema_id = sys.schemas.schema_id
WHERE sys.objects.TYPE = 'U' AND sys.objects.Name = 'Testing1' AND sys.schemas.Name ='dbo'
)
Query2:
SELECT @ColumnNamesWhenNoIdentity = COALESCE(@ColumnNamesWhenNoIdentity + ',', '') + Name +'= SOURCE.'+Name
FROM sys.columns WITH(NOLOCK) WHERE is_identity != 1 AND object_id =
(SELECT sys.objects.object_id FROM sys.objects WITH(NOLOCK)
INNER JOIN sys.schemas WITH(NOLOCK) ON sys.objects.schema_id = sys.schemas.schema_id
WHERE sys.objects.TYPE = 'U' AND sys.objects.Name = 'Testing2' AND sys.schemas.Name ='dbo'
)
View 8 Replies
View Related
Apr 12, 2015
I am new to SQL Programming. I am learning the basics. I am trying to create a simple query like this -
SELECT
Column_1,
Column_2,
Column_3,
10*Column_1 AS Column_4,
10*Column_2 AS Column_5,
-- I am not being able to understand how to do this particular step Column_1*Column_5 As Column_6
FROM Table_1
First 3 Columns are available within the Original Table_1
The Column_4 and Column_5 have been created by me, by doing some Calculations related to the original columns.
Now, when I try to do FURTHER CALCULATION on these newly created columns, then SQL Server does not allows that.
I was hoping that I will be able to use the Newly Created Columns 4 and 5 within this same query to do further more calculations, but that does not seems to be the case, or am I doing something wrong here ?
If I have to create a new column by the name of Column_6, which is actually a multiplication of Original Column_1 and Newly Created Column_5 "I tried this - Column_1*Column_5 As Column_6", then what is the possible solution for me ?
I have tried to present my problem in the simplest possible manner. The actual query has many original columns from Table_1 and many Calculated columns that are created by me. And now I have to do various calculations that involve making use of both these type of columns.
View 8 Replies
View Related
May 18, 2015
I would like to put a Clustered Index on a date column in a current heap, but one question/concern.This heap every month has thousands of rows deleted and even more added later. How much of an issue will this cause the Clustered Index as far as page splits? I was thinking Fill Factor of 70%.I would normally just test and still will on Dev box, but my Dev box is much smaller than production as far as power.
View 6 Replies
View Related
Jun 17, 2015
I need to encrypt some column level data in multiple tables in SQL server 2014. I've never tried encryption in SQL server 2014. How can I achieve it?
View 4 Replies
View Related
