SELECT TOP 5
total_worker_time/execution_count AS [Avg CPU Time],
(SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
statement_end_offset end -statement_start_offset)/2) FROM
sys.dm_exec_sql_text(sql_handle)) AS query_text
FROM sys.dm_exec_query_stats
ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I want
to understand this statement within the query above(SELECT
SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset = -1
then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
query_text
Where can i learn more about what that statement is actually trying to do ?
Hassan
The view sys.dm_exec_sql_text(sql_handle)) is showing you the currently
executing batch, which may be a block of many commands or could be a stored
procedure. The offsets are showing you which exact statement in the code is
actually running at the moment. This way you are not looking at the whole
batch of commands and trying to figure out which statement is actually
running.
So, picture a stored procedure with 1000 lines. Suppose you run this query
several times and you see the same value being returned, which we might say
are equip to lines 400 to 407, then you may have found the slow point in the
code that could use some extra work in tuning.
RLF
"Hassan" <hassan@.test.com> wrote in message
news:uonSdUVJIHA.5208@.TK2MSFTNGP04.phx.gbl...
> SELECT TOP 5
> total_worker_time/execution_count AS [Avg CPU Time],
> (SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
> statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
> statement_end_offset end -statement_start_offset)/2) FROM
> sys.dm_exec_sql_text(sql_handle)) AS query_text
> FROM sys.dm_exec_query_stats
> ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I
> want to understand this statement within the query above(SELECT
> SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset
> = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
> end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
> query_text
> Where can i learn more about what that statement is actually trying to do
> ?
>
Showing posts with label explain. Show all posts
Showing posts with label explain. Show all posts
Friday, March 23, 2012
Help explain statement start offset and end offset
SELECT TOP 5
total_worker_time/execution_count AS [Avg CPU Time],
(SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
statement_end_offset end -statement_start_offset)/2) FROM
sys.dm_exec_sql_text(sql_handle)) AS query_text
FROM sys.dm_exec_query_stats
ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I
want
to understand this statement within the query above(SELECT
SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset = -1
then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
query_text
Where can i learn more about what that statement is actually trying to do ?Hassan
The view sys.dm_exec_sql_text(sql_handle)) is showing you the currently
executing batch, which may be a block of many commands or could be a stored
procedure. The offsets are showing you which exact statement in the code is
actually running at the moment. This way you are not looking at the whole
batch of commands and trying to figure out which statement is actually
running.
So, picture a stored procedure with 1000 lines. Suppose you run this query
several times and you see the same value being returned, which we might say
are equip to lines 400 to 407, then you may have found the slow point in the
code that could use some extra work in tuning.
RLF
"Hassan" <hassan@.test.com> wrote in message
news:uonSdUVJIHA.5208@.TK2MSFTNGP04.phx.gbl...
> SELECT TOP 5
> total_worker_time/execution_count AS [Avg CPU Time],
> (SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
> statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
> statement_end_offset end -statement_start_offset)/2) FROM
> sys.dm_exec_sql_text(sql_handle)) AS query_text
> FROM sys.dm_exec_query_stats
> ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and
I
> want to understand this statement within the query above(SELECT
> SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset
> = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
> end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
> query_text
> Where can i learn more about what that statement is actually trying to do
> ?
>
total_worker_time/execution_count AS [Avg CPU Time],
(SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
statement_end_offset end -statement_start_offset)/2) FROM
sys.dm_exec_sql_text(sql_handle)) AS query_text
FROM sys.dm_exec_query_stats
ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I
want
to understand this statement within the query above(SELECT
SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset = -1
then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
query_text
Where can i learn more about what that statement is actually trying to do ?Hassan
The view sys.dm_exec_sql_text(sql_handle)) is showing you the currently
executing batch, which may be a block of many commands or could be a stored
procedure. The offsets are showing you which exact statement in the code is
actually running at the moment. This way you are not looking at the whole
batch of commands and trying to figure out which statement is actually
running.
So, picture a stored procedure with 1000 lines. Suppose you run this query
several times and you see the same value being returned, which we might say
are equip to lines 400 to 407, then you may have found the slow point in the
code that could use some extra work in tuning.
RLF
"Hassan" <hassan@.test.com> wrote in message
news:uonSdUVJIHA.5208@.TK2MSFTNGP04.phx.gbl...
> SELECT TOP 5
> total_worker_time/execution_count AS [Avg CPU Time],
> (SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
> statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
> statement_end_offset end -statement_start_offset)/2) FROM
> sys.dm_exec_sql_text(sql_handle)) AS query_text
> FROM sys.dm_exec_query_stats
> ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and
I
> want to understand this statement within the query above(SELECT
> SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset
> = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
> end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
> query_text
> Where can i learn more about what that statement is actually trying to do
> ?
>
Help explain statement start offset and end offset
SELECT TOP 5
total_worker_time/execution_count AS [Avg CPU Time],
(SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
statement_end_offset end -statement_start_offset)/2) FROM
sys.dm_exec_sql_text(sql_handle)) AS query_text
FROM sys.dm_exec_query_stats
ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I want
to understand this statement within the query above(SELECT
SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset = -1
then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
query_text
Where can i learn more about what that statement is actually trying to do ?Hassan
The view sys.dm_exec_sql_text(sql_handle)) is showing you the currently
executing batch, which may be a block of many commands or could be a stored
procedure. The offsets are showing you which exact statement in the code is
actually running at the moment. This way you are not looking at the whole
batch of commands and trying to figure out which statement is actually
running.
So, picture a stored procedure with 1000 lines. Suppose you run this query
several times and you see the same value being returned, which we might say
are equip to lines 400 to 407, then you may have found the slow point in the
code that could use some extra work in tuning.
RLF
"Hassan" <hassan@.test.com> wrote in message
news:uonSdUVJIHA.5208@.TK2MSFTNGP04.phx.gbl...
> SELECT TOP 5
> total_worker_time/execution_count AS [Avg CPU Time],
> (SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
> statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
> statement_end_offset end -statement_start_offset)/2) FROM
> sys.dm_exec_sql_text(sql_handle)) AS query_text
> FROM sys.dm_exec_query_stats
> ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I
> want to understand this statement within the query above(SELECT
> SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset
> = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
> end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
> query_text
> Where can i learn more about what that statement is actually trying to do
> ?
>
total_worker_time/execution_count AS [Avg CPU Time],
(SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
statement_end_offset end -statement_start_offset)/2) FROM
sys.dm_exec_sql_text(sql_handle)) AS query_text
FROM sys.dm_exec_query_stats
ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I want
to understand this statement within the query above(SELECT
SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset = -1
then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
query_text
Where can i learn more about what that statement is actually trying to do ?Hassan
The view sys.dm_exec_sql_text(sql_handle)) is showing you the currently
executing batch, which may be a block of many commands or could be a stored
procedure. The offsets are showing you which exact statement in the code is
actually running at the moment. This way you are not looking at the whole
batch of commands and trying to figure out which statement is actually
running.
So, picture a stored procedure with 1000 lines. Suppose you run this query
several times and you see the same value being returned, which we might say
are equip to lines 400 to 407, then you may have found the slow point in the
code that could use some extra work in tuning.
RLF
"Hassan" <hassan@.test.com> wrote in message
news:uonSdUVJIHA.5208@.TK2MSFTNGP04.phx.gbl...
> SELECT TOP 5
> total_worker_time/execution_count AS [Avg CPU Time],
> (SELECT SUBSTRING(text,statement_start_offset/2,(CASE WHEN
> statement_end_offset = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE
> statement_end_offset end -statement_start_offset)/2) FROM
> sys.dm_exec_sql_text(sql_handle)) AS query_text
> FROM sys.dm_exec_query_stats
> ORDER BY [Avg CPU Time] DESCI saw this query to give top CPU hogs and I
> want to understand this statement within the query above(SELECT
> SUBSTRING(text,statement_start_offset/2,(CASE WHEN statement_end_offset
> = -1 then LEN(CONVERT(nvarchar(max), text)) * 2 ELSE statement_end_offset
> end -statement_start_offset)/2) FROM sys.dm_exec_sql_text(sql_handle)) AS
> query_text
> Where can i learn more about what that statement is actually trying to do
> ?
>
Help creating a Transact SQL Insert Statement
Hi there can anyone help me to create a SQL Insert Statement. I dont know SQL at all.
To explain, I have two web pages. search.asp and results.asp.
search.asp has the following.
Form Name: searchForm
Set to: Post
Action: results.asp
Text Field: Keyword
Drop Down: CategoryTable
Drop Down: Location
UserName Session Variable: MM_UserName
results.asp has the following SQL which pulls all the results.
SELECT SupplierName, Location, ShortDescription, TimberSpecies, CategoryTitle, Country, CustomerType
FROM Query1
WHERE TimberSpecies LIKE '%MMColParam%' AND CategoryTitle LIKE '%MMColParam2%' AND Location LIKE '%MMColParam3%' AND CustomerType = 'Trade/Retail'
ORDER BY CategoryTitle, TimberSpecies ASC
The database & form I want to insert into.
tblSearcheResults
idSearch (AutoNumber)
location (Text) "Want to insert the 'Location' result here"
category (Text) "Want to insert the 'CategoryTable' result here"
user (Text) "Want to insert the UserName Session Variable result here"
result (Text) "Want to insert the 'Keyword' result here"
Please ask if u need more info.
Mally
Hi,
INSERT INTO tblSearchResults
(
location,
category,
user,
result
)
VALUES
(
Location, --should be due to the POST action in Request.Form("Location")
category, --should be due to the POST action in Request.Form("category")
user, --should be due to the POST action in Session("MM_UserName")
keyword, --should be due to the POST action in Request.Form("keyword")
)
Variable have to be read first and the query string to be constructed before sending it to SQL Server, keep in mind that you have to quote the string while composing the SQL String.
HTH, Jens Suessmeyer.
http://www.sqlserver2005.de
Wednesday, March 21, 2012
help and advice on waittype 0x0044
Hi,
I wonder if anyone can shed any light on the following as i just can't
explain it.
A user is running an update on a 500m+ row table setting a column
value, computing its value from another column in the table. It's now
been running for 23hours.
The server is Itanium 64, enterprise 2005, SAN based storage and it
usually handles anything with this volume quite quickly, probably
about 30 mins or so.
There is nothing else running currently although overnight batches,
backups etc have been running within the last 23 hours.
In sysprocess it showing the following :-
spid kpid blocked waittype waittime
lastwaittype waitresource
52 5236 0 0x0044 30
PAGEIOLATCH_EX 6:13:1754732
the process seems to stay in this waittype for a few secnds and then
goes to a 0x0000 and then back into this one again. I can see from the
IO counter that IO is increasing and also looking at the current IO i
see the following so presume the query is still working :-
select
database_id,
file_id,
io_stall,
io_pending_ms_ticks,
scheduler_address
from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
sys.dm_io_pending_io_requests as t2
where t1.file_handle = t2.io_handle
gives results :-
6 13 151115052 10 0x0000000008624080
I just can't explain why it is so slow when nothing else is ruuning.
Anyone have any ideas on what i can check on?
Thanks
Ian.Regarding PAGEIOLATCH_EX --I/O page latch exclusive. Waiting for the write of
an I/O page.
I think its just showing that disk activity is getting performed as updates
are currently executing. There is a possibility of slow disk subsystem(that
you can verify using disk counters in performance monitor like average disk
queue length, %disk time etc.).
Is it possible in your case to perform batch by batch updates? Also, whts
the recovery model of this database.
Manu
"ianwr" wrote:
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.
>|||Hi Manu,
The recovery model is simple mode and i suppose the developer can do
it in batches but is a one off and i told him to leave it running
because it would take just as long to roll back.
Disk subsystem is usally quite quick, i can create an index on 600m+
row table in about 25 mins so for this to take 23 hours is really
strange|||Ian,
I see that on my machines a non-zero current waittype (almost?) always is
paired with the same lastwaittype, so I assume that (with no information to
the contrary) that 0x0044 = PAGEIOLATCH_EX.
It that is correct, then from
http://msdn2.microsoft.com/en-us/library/ms179984.aspx it says: Occurs when
a task is waiting on a latch for a buffer that is in an I/O request. The
latch request is in Exclusive mode. Long waits may indicate problems with
the disk subsystem.
So, although I don't know what is wrong, this seems to indicate some
problems with your SAN. I am not SAN wise, but it suggests that either
there is a communication problem between server and SAN or the SAN is having
disk problems.
FWIW,
RLF
"ianwr" <ianwrigglesworth@.yahoo.co.uk> wrote in message
news:b794459f-13ed-49b4-b444-3609f30ac354@.v4g2000hsf.googlegroups.com...
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.|||Thanks Russell,
I'm thinking its probably the SAN, I suspect they probably have other
apps running on the same spindles as everythign seems to be setup
completely wrong at this client site.
I'm wondering if there is something else happening on the san that is
causing things to go slow ... how lovely it would be to have some SAN
diagnostic tool that i could run from my desktop rather than go
through the san people. lol.
Anyway thanks for your help
Ian.
I wonder if anyone can shed any light on the following as i just can't
explain it.
A user is running an update on a 500m+ row table setting a column
value, computing its value from another column in the table. It's now
been running for 23hours.
The server is Itanium 64, enterprise 2005, SAN based storage and it
usually handles anything with this volume quite quickly, probably
about 30 mins or so.
There is nothing else running currently although overnight batches,
backups etc have been running within the last 23 hours.
In sysprocess it showing the following :-
spid kpid blocked waittype waittime
lastwaittype waitresource
52 5236 0 0x0044 30
PAGEIOLATCH_EX 6:13:1754732
the process seems to stay in this waittype for a few secnds and then
goes to a 0x0000 and then back into this one again. I can see from the
IO counter that IO is increasing and also looking at the current IO i
see the following so presume the query is still working :-
select
database_id,
file_id,
io_stall,
io_pending_ms_ticks,
scheduler_address
from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
sys.dm_io_pending_io_requests as t2
where t1.file_handle = t2.io_handle
gives results :-
6 13 151115052 10 0x0000000008624080
I just can't explain why it is so slow when nothing else is ruuning.
Anyone have any ideas on what i can check on?
Thanks
Ian.Regarding PAGEIOLATCH_EX --I/O page latch exclusive. Waiting for the write of
an I/O page.
I think its just showing that disk activity is getting performed as updates
are currently executing. There is a possibility of slow disk subsystem(that
you can verify using disk counters in performance monitor like average disk
queue length, %disk time etc.).
Is it possible in your case to perform batch by batch updates? Also, whts
the recovery model of this database.
Manu
"ianwr" wrote:
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.
>|||Hi Manu,
The recovery model is simple mode and i suppose the developer can do
it in batches but is a one off and i told him to leave it running
because it would take just as long to roll back.
Disk subsystem is usally quite quick, i can create an index on 600m+
row table in about 25 mins so for this to take 23 hours is really
strange|||Ian,
I see that on my machines a non-zero current waittype (almost?) always is
paired with the same lastwaittype, so I assume that (with no information to
the contrary) that 0x0044 = PAGEIOLATCH_EX.
It that is correct, then from
http://msdn2.microsoft.com/en-us/library/ms179984.aspx it says: Occurs when
a task is waiting on a latch for a buffer that is in an I/O request. The
latch request is in Exclusive mode. Long waits may indicate problems with
the disk subsystem.
So, although I don't know what is wrong, this seems to indicate some
problems with your SAN. I am not SAN wise, but it suggests that either
there is a communication problem between server and SAN or the SAN is having
disk problems.
FWIW,
RLF
"ianwr" <ianwrigglesworth@.yahoo.co.uk> wrote in message
news:b794459f-13ed-49b4-b444-3609f30ac354@.v4g2000hsf.googlegroups.com...
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.|||Thanks Russell,
I'm thinking its probably the SAN, I suspect they probably have other
apps running on the same spindles as everythign seems to be setup
completely wrong at this client site.
I'm wondering if there is something else happening on the san that is
causing things to go slow ... how lovely it would be to have some SAN
diagnostic tool that i could run from my desktop rather than go
through the san people. lol.
Anyway thanks for your help
Ian.
help and advice on waittype 0x0044
Hi,
I wonder if anyone can shed any light on the following as i just can't
explain it.
A user is running an update on a 500m+ row table setting a column
value, computing its value from another column in the table. It's now
been running for 23hours.
The server is Itanium 64, enterprise 2005, SAN based storage and it
usually handles anything with this volume quite quickly, probably
about 30 mins or so.
There is nothing else running currently although overnight batches,
backups etc have been running within the last 23 hours.
In sysprocess it showing the following :-
spid kpid blocked waittype waittime
lastwaittype waitresource
52 5236 0 0x0044 30
PAGEIOLATCH_EX 6:13:1754732
the process seems to stay in this waittype for a few secnds and then
goes to a 0x0000 and then back into this one again. I can see from the
IO counter that IO is increasing and also looking at the current IO i
see the following so presume the query is still working :-
select
database_id,
file_id,
io_stall,
io_pending_ms_ticks,
scheduler_address
from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
sys.dm_io_pending_io_requests as t2
where t1.file_handle = t2.io_handle
gives results :-
6 13 151115052 10 0x0000000008624080
I just can't explain why it is so slow when nothing else is ruuning.
Anyone have any ideas on what i can check on?
Thanks
Ian.Regarding PAGEIOLATCH_EX --I/O page latch exclusive. Waiting for the write o
f
an I/O page.
I think its just showing that disk activity is getting performed as updates
are currently executing. There is a possibility of slow disk subsystem(that
you can verify using disk counters in performance monitor like average disk
queue length, %disk time etc.).
Is it possible in your case to perform batch by batch updates? Also, whts
the recovery model of this database.
Manu
"ianwr" wrote:
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.
>|||Ian,
I see that on my machines a non-zero current waittype (almost?) always is
paired with the same lastwaittype, so I assume that (with no information to
the contrary) that 0x0044 = PAGEIOLATCH_EX.
It that is correct, then from
http://msdn2.microsoft.com/en-us/library/ms179984.aspx it says: Occurs when
a task is waiting on a latch for a buffer that is in an I/O request. The
latch request is in Exclusive mode. Long waits may indicate problems with
the disk subsystem.
So, although I don't know what is wrong, this seems to indicate some
problems with your SAN. I am not SAN wise, but it suggests that either
there is a communication problem between server and SAN or the SAN is having
disk problems.
FWIW,
RLF
"ianwr" <ianwrigglesworth@.yahoo.co.uk> wrote in message
news:b794459f-13ed-49b4-b444-3609f30ac354@.v4g2000hsf.googlegroups.com...
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.|||Hi Manu,
The recovery model is simple mode and i suppose the developer can do
it in batches but is a one off and i told him to leave it running
because it would take just as long to roll back.
Disk subsystem is usally quite quick, i can create an index on 600m+
row table in about 25 mins so for this to take 23 hours is really
strange|||Thanks Russell,
I'm thinking its probably the SAN, I suspect they probably have other
apps running on the same spindles as everythign seems to be setup
completely wrong at this client site.
I'm wondering if there is something else happening on the san that is
causing things to go slow ... how lovely it would be to have some SAN
diagnostic tool that i could run from my desktop rather than go
through the san people. lol.
Anyway thanks for your help
Ian.
I wonder if anyone can shed any light on the following as i just can't
explain it.
A user is running an update on a 500m+ row table setting a column
value, computing its value from another column in the table. It's now
been running for 23hours.
The server is Itanium 64, enterprise 2005, SAN based storage and it
usually handles anything with this volume quite quickly, probably
about 30 mins or so.
There is nothing else running currently although overnight batches,
backups etc have been running within the last 23 hours.
In sysprocess it showing the following :-
spid kpid blocked waittype waittime
lastwaittype waitresource
52 5236 0 0x0044 30
PAGEIOLATCH_EX 6:13:1754732
the process seems to stay in this waittype for a few secnds and then
goes to a 0x0000 and then back into this one again. I can see from the
IO counter that IO is increasing and also looking at the current IO i
see the following so presume the query is still working :-
select
database_id,
file_id,
io_stall,
io_pending_ms_ticks,
scheduler_address
from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
sys.dm_io_pending_io_requests as t2
where t1.file_handle = t2.io_handle
gives results :-
6 13 151115052 10 0x0000000008624080
I just can't explain why it is so slow when nothing else is ruuning.
Anyone have any ideas on what i can check on?
Thanks
Ian.Regarding PAGEIOLATCH_EX --I/O page latch exclusive. Waiting for the write o
f
an I/O page.
I think its just showing that disk activity is getting performed as updates
are currently executing. There is a possibility of slow disk subsystem(that
you can verify using disk counters in performance monitor like average disk
queue length, %disk time etc.).
Is it possible in your case to perform batch by batch updates? Also, whts
the recovery model of this database.
Manu
"ianwr" wrote:
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.
>|||Ian,
I see that on my machines a non-zero current waittype (almost?) always is
paired with the same lastwaittype, so I assume that (with no information to
the contrary) that 0x0044 = PAGEIOLATCH_EX.
It that is correct, then from
http://msdn2.microsoft.com/en-us/library/ms179984.aspx it says: Occurs when
a task is waiting on a latch for a buffer that is in an I/O request. The
latch request is in Exclusive mode. Long waits may indicate problems with
the disk subsystem.
So, although I don't know what is wrong, this seems to indicate some
problems with your SAN. I am not SAN wise, but it suggests that either
there is a communication problem between server and SAN or the SAN is having
disk problems.
FWIW,
RLF
"ianwr" <ianwrigglesworth@.yahoo.co.uk> wrote in message
news:b794459f-13ed-49b4-b444-3609f30ac354@.v4g2000hsf.googlegroups.com...
> Hi,
> I wonder if anyone can shed any light on the following as i just can't
> explain it.
> A user is running an update on a 500m+ row table setting a column
> value, computing its value from another column in the table. It's now
> been running for 23hours.
> The server is Itanium 64, enterprise 2005, SAN based storage and it
> usually handles anything with this volume quite quickly, probably
> about 30 mins or so.
> There is nothing else running currently although overnight batches,
> backups etc have been running within the last 23 hours.
> In sysprocess it showing the following :-
> spid kpid blocked waittype waittime
> lastwaittype waitresource
> 52 5236 0 0x0044 30
> PAGEIOLATCH_EX 6:13:1754732
> the process seems to stay in this waittype for a few secnds and then
> goes to a 0x0000 and then back into this one again. I can see from the
> IO counter that IO is increasing and also looking at the current IO i
> see the following so presume the query is still working :-
> select
> database_id,
> file_id,
> io_stall,
> io_pending_ms_ticks,
> scheduler_address
> from sys.dm_io_virtual_file_stats(NULL, NULL)t1,
> sys.dm_io_pending_io_requests as t2
> where t1.file_handle = t2.io_handle
> gives results :-
> 6 13 151115052 10 0x0000000008624080
> I just can't explain why it is so slow when nothing else is ruuning.
> Anyone have any ideas on what i can check on?
> Thanks
> Ian.|||Hi Manu,
The recovery model is simple mode and i suppose the developer can do
it in batches but is a one off and i told him to leave it running
because it would take just as long to roll back.
Disk subsystem is usally quite quick, i can create an index on 600m+
row table in about 25 mins so for this to take 23 hours is really
strange|||Thanks Russell,
I'm thinking its probably the SAN, I suspect they probably have other
apps running on the same spindles as everythign seems to be setup
completely wrong at this client site.
I'm wondering if there is something else happening on the san that is
causing things to go slow ... how lovely it would be to have some SAN
diagnostic tool that i could run from my desktop rather than go
through the san people. lol.
Anyway thanks for your help
Ian.
Friday, February 24, 2012
help
Can anyone explain me why connections to my sql server is
beeing done through names pipes and NOT TCP/IP?
It's your connection string. If you specify the server as a Name (e.g.
Server1) then you will connect through Named Pipes. If you spcify the server
as an IP address or a DNS name (e.g. 123.12.34.123 or www.Name.com) then you
will connect via TCP/IP. If using a DNS name, make sure you have can resolve
the IP address.
By default SQL installs with Named Pipes & TCP/IP. If you want other
protocols you may add them. Also, you may remove protocols such as Named
Pipes, but I wouldn't.
Sam
"
" wrote:
> Can anyone explain me why connections to my sql server is
> beeing done through names pipes and NOT TCP/IP?
>
beeing done through names pipes and NOT TCP/IP?
It's your connection string. If you specify the server as a Name (e.g.
Server1) then you will connect through Named Pipes. If you spcify the server
as an IP address or a DNS name (e.g. 123.12.34.123 or www.Name.com) then you
will connect via TCP/IP. If using a DNS name, make sure you have can resolve
the IP address.
By default SQL installs with Named Pipes & TCP/IP. If you want other
protocols you may add them. Also, you may remove protocols such as Named
Pipes, but I wouldn't.
Sam
"
" wrote:> Can anyone explain me why connections to my sql server is
> beeing done through names pipes and NOT TCP/IP?
>
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