Blocking issue

We are experencing some serious locking issue on sql server (sql2000). Basically a method in VB component opens a recordset which loops through a table A (about 100,000 times), inside the loop, it calls a stpred proc and does an update on table A. Each update in the loop is quite small, a few records at the most. Table A has an update trigger which insert the updated records to a history table then delete this record from table a. There are some f other queries running on table a. The big update loop on table A causes locking issues. With every update in the loop, there are hundred of locks on the delete job when it's blocking other jobs. I can't fingure out why continuous small updates opens so many locks(by looking at sp_lock) therefore blocks other process that query the same table. Any help is appreciated. thanks.Ouch. That's just asking for locking problems... Why do you this using a
cursor? Have you tried doing it in a set-based fashion?
Andrés Taylor
"Tom" <anonymous@.discussions.microsoft.com> wrote in message
news:182071FF-981D-4139-A29F-11B81157BFD2@.microsoft.com...
> We are experencing some serious locking issue on sql server (sql2000).
Basically a method in VB component opens a recordset which loops through a
table A (about 100,000 times), inside the loop, it calls a stpred proc and
does an update on table A. Each update in the loop is quite small, a few
records at the most. Table A has an update trigger which insert the updated
records to a history table then delete this record from table a. There are
some f other queries running on table a. The big update loop on table A
causes locking issues. With every update in the loop, there are hundred of
locks on the delete job when it's blocking other jobs. I can't fingure out
why continuous small updates opens so many locks(by looking at sp_lock)
therefore blocks other process that query the same table. Any help is
appreciated. thanks.|||Tom,
Sounds like a very poor way in general to do updates and you should probably
look into redoing the task using as much set and server based approaches as
possible. But in this case I think the real issue might be that there is a
BEGIN TRAN issued (either implicitly or explicitly) at the beginning and
thus the whole operation is wrapped in one large transaction. You can use
sp_who2, sp_lock and profiler to see for sure what is going on.
--
Andrew J. Kelly
SQL Server MVP
"Tom" <anonymous@.discussions.microsoft.com> wrote in message
news:182071FF-981D-4139-A29F-11B81157BFD2@.microsoft.com...
> We are experencing some serious locking issue on sql server (sql2000).
Basically a method in VB component opens a recordset which loops through a
table A (about 100,000 times), inside the loop, it calls a stpred proc and
does an update on table A. Each update in the loop is quite small, a few
records at the most. Table A has an update trigger which insert the updated
records to a history table then delete this record from table a. There are
some f other queries running on table a. The big update loop on table A
causes locking issues. With every update in the loop, there are hundred of
locks on the delete job when it's blocking other jobs. I can't fingure out
why continuous small updates opens so many locks(by looking at sp_lock)
therefore blocks other process that query the same table. Any help is
appreciated. thanks.

Blank fields in Excel file

I am trying to validate and import a Excel file into the database table using script component. The file contains some blank columns in the sheet. How can I handle the blank spaces while validating the file in the Script Component?
The code is as follows:

Dim excelcmd As OleDbCommand = New OleDbCommand("SELECT Item,TaxCode,ItemDescription FROM [Input$]WHERE LEN(Item)>=0 AND LEN(ItemDescription)>=0 AND LEN(TaxCode)>=0", excelConn)
Dim excelreader As OleDbDataReader = excelcmd.ExecuteReader()
Dim row As Integer = 0

While excelreader.Read()
NameValsBuffer.AddRow()
NameValsBuffer.ItemCode = CStr(IIf(excelreader.GetString(0).Length = 0, "#", excelreader.GetString(0)))
NameValsBuffer.TaxCode = CStr(IIf(excelreader.GetString(1).Length = 0, "#", excelreader.GetString(1)))
NameValsBuffer.ItemDescription = CStr(IIf(excelreader.GetString(2).Length = 0, "#", excelreader.GetString(2)))
NameValsBuffer.CompanyId = Me.Variables.CompanyId
NameValsBuffer.UserId = Me.Variables.UserId
End WhileThe thread title says "blank fields", while the text of the question references "blank columns", and lastly "blank spaces". Can you give a small pictorial representation of the problem? It sounds relatively easy to solve, but I'd like to make what the nature of the issue is first.|||

Item

ItemDescription

TaxCode

AAA123

Sample Item 1

XXXXXX

BBB255

Sample Item 2

AAAAA

CCC366

Sample Item 3

BBBBB

XDDD489

Sample Item 4

CCCCC

5EEE

Sample Item 5

DDDDDD

6FFF

Sample Item 6

EEEEEE

GGG

Sample Item 7

FFFFFFF

HHH

Sample Item 8

GGGGG

III

Sample Item 9

HHHHHH

JJJ

Sample Item 10

IIIIIIIIIII

KKK

Sample Item 11

ZZZZZZZZ

MMM

The value in the last row for the ItemDescription and TaxCode is null..so thats the problem I am facing when I am trying to validate and upload data.


|||First off, I'm not sure why you're using a script component, when an ADO.NET connection with the following connnection string will work fine:

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\MyExcel.xls;Extended Properties="Excel 8.0;HDR=Yes;IMEX=1"

In your dataflow, rather than script source, use a DataReader source and set your select statement in the SqlCommand property (e.g. SELECT * FROM [sheet1$] WHERE ...) . At that point, you can do whatever you want in the pipeline, including using conditional splits and/or derived columns as appropriate to handle the NULL ItemDescription and TaxCode pipeline columns, and adding your static columns via a derived column transform.

However, if for whatever reason you need to use a script component, you can use the following CreateNewOutput rows override to handle null cells. "OrElse" is used because its a short-curcuit operator, and .Item is used because it returns an Object, which can hold either a String or a DBNull object. Note there is no "WHERE" clause either, since nulls are handled in the while loop.

Public Overrides Sub

CreateNewOutputRows()
Dim

excelcmd As OleDbCommand = New OleDbCommand("SELECT

Item,TaxCode,ItemDescription FROM [Sheet1$]", excelConn)
Dim

excelreader As OleDbDataReader =

excelcmd.ExecuteReader()
Dim row

As Integer = 0

While

excelreader.Read()
With

NameValsBuffer
.AddRow()
.ItemCode = CStr(IIf(IsDBNull(excelreader.Item(0)) OrElse excelreader.GetString(0).Length = 0, "#", excelreader.Item(0)))
.TaxCode = CStr(IIf(IsDBNull(excelreader.Item(1))

OrElse excelreader.GetString(1).Length = 0, "#", excelreader.Item(1)))
.ItemDescription = CStr(IIf(IsDBNull(excelreader.Item(2)) OrElse excelreader.GetString(2).Length = 0, "#", excelreader.Item(2)))
End

With
End While
End Sub

|||Just to add to what jaegd mentioned, this may also be done with following components: Excel Source, Conditional Split, and your destination component.

In conditional split the condition could be set as follows:
ISNULL(ItemDescription) || ISNULL(TaxCode)

HTH..

Blank fields in Excel file

I am trying to validate and import a Excel file into the database table using script component. The file contains some blank columns in the sheet. How can I handle the blank spaces while validating the file in the Script Component?
The code is as follows:

Dim excelcmd As OleDbCommand = New OleDbCommand("SELECT Item,TaxCode,ItemDescription FROM [Input$]WHERE LEN(Item)>=0 AND LEN(ItemDescription)>=0 AND LEN(TaxCode)>=0", excelConn)
Dim excelreader As OleDbDataReader = excelcmd.ExecuteReader()
Dim row As Integer = 0

While excelreader.Read()
NameValsBuffer.AddRow()
NameValsBuffer.ItemCode = CStr(IIf(excelreader.GetString(0).Length = 0, "#", excelreader.GetString(0)))
NameValsBuffer.TaxCode = CStr(IIf(excelreader.GetString(1).Length = 0, "#", excelreader.GetString(1)))
NameValsBuffer.ItemDescription = CStr(IIf(excelreader.GetString(2).Length = 0, "#", excelreader.GetString(2)))
NameValsBuffer.CompanyId = Me.Variables.CompanyId
NameValsBuffer.UserId = Me.Variables.UserId
End WhileThe thread title says "blank fields", while the text of the question references "blank columns", and lastly "blank spaces". Can you give a small pictorial representation of the problem? It sounds relatively easy to solve, but I'd like to make what the nature of the issue is first.|||

Item

ItemDescription

TaxCode

AAA123

Sample Item 1

XXXXXX

BBB255

Sample Item 2

AAAAA

CCC366

Sample Item 3

BBBBB

XDDD489

Sample Item 4

CCCCC

5EEE

Sample Item 5

DDDDDD

6FFF

Sample Item 6

EEEEEE

GGG

Sample Item 7

FFFFFFF

HHH

Sample Item 8

GGGGG

III

Sample Item 9

HHHHHH

JJJ

Sample Item 10

IIIIIIIIIII

KKK

Sample Item 11

ZZZZZZZZ

MMM

The value in the last row for the ItemDescription and TaxCode is null..so thats the problem I am facing when I am trying to validate and upload data.


|||First off, I'm not sure why you're using a script component, when an ADO.NET connection with the following connnection string will work fine:

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\MyExcel.xls;Extended Properties="Excel 8.0;HDR=Yes;IMEX=1"

In your dataflow, rather than script source, use a DataReader source and set your select statement in the SqlCommand property (e.g. SELECT * FROM [sheet1$] WHERE ...) . At that point, you can do whatever you want in the pipeline, including using conditional splits and/or derived columns as appropriate to handle the NULL ItemDescription and TaxCode pipeline columns, and adding your static columns via a derived column transform.

However, if for whatever reason you need to use a script component, you can use the following CreateNewOutput rows override to handle null cells. "OrElse" is used because its a short-curcuit operator, and .Item is used because it returns an Object, which can hold either a String or a DBNull object. Note there is no "WHERE" clause either, since nulls are handled in the while loop.

Public Overrides Sub

CreateNewOutputRows()
Dim

excelcmd As OleDbCommand = New OleDbCommand("SELECT

Item,TaxCode,ItemDescription FROM [Sheet1$]", excelConn)
Dim

excelreader As OleDbDataReader =

excelcmd.ExecuteReader()
Dim row

As Integer = 0

While

excelreader.Read()
With

NameValsBuffer
.AddRow()
.ItemCode = CStr(IIf(IsDBNull(excelreader.Item(0)) OrElse excelreader.GetString(0).Length = 0, "#", excelreader.Item(0)))
.TaxCode = CStr(IIf(IsDBNull(excelreader.Item(1))

OrElse excelreader.GetString(1).Length = 0, "#", excelreader.Item(1)))
.ItemDescription = CStr(IIf(IsDBNull(excelreader.Item(2)) OrElse excelreader.GetString(2).Length = 0, "#", excelreader.Item(2)))
End

With
End While
End Sub

|||Just to add to what jaegd mentioned, this may also be done with following components: Excel Source, Conditional Split, and your destination component.

In conditional split the condition could be set as follows:
ISNULL(ItemDescription) || ISNULL(TaxCode)

HTH..