How To Lock A Table Or Row In Sql?
hi, i have an application that updates some records in sql tables, and i want to do a web application that updates records in the some database-table(sql) so, my question is how can i lock the row or table so i dont have concurrency problems.tnx in advance.
H/W-Dual PIII, 1GB RAM, 25GB Hard drives
S/W-NT 4.0 SP5, sqlserver 7.0 sp1, MTS, VB COM objs, ADO 2.1
This one is giving me some extra gray......
We have an order entry system, where we want to "create" invoices from about
20000- 25000 orders
at a time we WANT this to be a single transaction speed is not the issue
concurrency IS we DO not want
SQL to escalate the lock to table, but as we watch with sp_lock, row lock
occur for the first 2-3000 rows then it becomes a table lock.
I have read that if a query involves a table scan then it will escalate to a
table lock , that is why we have the hint to use the PK_OrderMain index, I thought sp_indexoption was going to help but all you can do is stop row/page locks
Does any one know how to stop sqlserver from automagically putting table
locks on ??????
our VB code looks some thing like this
sql = SELECT blah FROM OrderMain WITH
(ROWLOCK,UPDLOCK,INDEX=PK_OrderMain) WHERE OrderMain.OrderID in
(SELECT OrderMain.OrderID FROM OrderMain WITH (READCOMMITTED) WHERE
rs.open sql .....
while not rs.eof
if not errorflag
I want to lock a table so others cannot lock it but able to read it inside transactions.
The coding I need is something like this: set implicit_transactions on begin transaction select * from table1 with (tablock, holdlock) update table2 set field1 = 'test' commit transaction commit transaction
I have tried the coding above, it won't prevent others from locking table1.
So, I changed the tablock to tablockx to prevent others from locking table1. But this will also prevent others from reading table1. So, how can I lock table1 so others cannot lock it but still able to read it?
Thank you for any help
This problem almost drives me crazy, hope I can get some hints from you guyz!!!
Ok, here is the situation:
I wanna only one users 2 modify the data(update) from my page each time, and if at the same time, there are some other users connecting my database through .aspx page, they can only browse the data until the first users finish updating.
It seems I need to implement locking the database, but I am not sure how I am gonna do that using asp.net!!!
Thanx in advance!
Hi,If I run an insert statement from the query analyzer and then try toopen the table from enterprise manager then it takes long time to openthe table. But this problem dissapears when i put the statement insideBegin/End Transaction statement.Any idea why this is happening?Thank in advance.Taw.
Which lock type or isolation level should I use to be sure that no onewill read or write or do anything with the table I'm using?Code block should look something like this:lock tableread value from tablechange value to new_valueupdate table set value = new_valuerelease lockWhile I'm changing the value absolutly no one should be able to readfrom the table.
I am having a VB application running for the SQL SERVER DB. The VB application is installed on the multiple of PCs in the network. Now when I am trying to fetch the same from all the different PCs simultaneously, its amazingly fast. But the issue comes when I am trying to update the same table (but different rows) from the different PCs simultaneously. The time taken is directly proportaional to the number of users. I am not getting what could be the problem? Can any one suggest me the approch? Is it some related to table / row / page locking? As all the connections are trying to update on the same table. I checked the isolation level. Its default, "READ COMMITTED". Kindly suggest...
Thanks in advance........
Hai to all,
I want to lock a patricular table during my transaction is this possible, for Example
Create sp() as
Do Some work
Relaese the Lock
How can we know that particular table is locked.
Is there any way to lock tables in SQL Server?
How do I do a simple table lock?
In my server i am getting this error how can i slove this error
could u people any body please help me
Table Lock Wait Time Per Second is 867.3330
milliseconds per second, which exceeds threshold of 10
milliseconds per second."
Hi,I need to lock a table so that Inserts are prevented as well as deleted andupdates. At present I'm thinking this might do it:SELECT * FROM myTable WITH(UPLOCK)but then again I'm not sure whether this will cover the insert case.Thanks,Robin
HiI want to lock a table using JDBC as I want to perform some query's (readand write) in exclusive mode. Different threads will be executing the samecode simultaneously. I am using the following statementsStatement stmt = connection.createStatement();stmt.executeUpdate("lock table STATUS_TBL in EXCLUSIVE mode");but am getting the following error[Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]Line 1: Incorrectsyntax near 'STATUS_TBL'.can somebody tell the correct syntax for the lock table statement.Thanks
How can i give a table wise exclusive lock in MSSQL Server ?
I got the description but, How can I apply this ?
The sql :
LOCK TABLE <tablename> IN EXCLUSIVE MODE
is not working.
Is there any query/method to do this ?
Please help ...
About Exclusive locks
Exclusive (X) locks are used for data modification operations, such as UPDATE, INSERT, or DELETE.
Other transactions cannot read or modify data locked with an Exclusive (X) lock. If a Shared (S) exists, other transactions cannot acquire an Exclusive (X) lock.
I need to update a row but keep a lock on the table (so no one else can update it) while I do run some more code. In Oracle, it always locks whatever you update until you hit commit, but sql server works opposite. How do I tell it not to commit a statement, or how would I explicitly get a lock and then release it later?
I need confirmation from you SQL Server experts out there. Please let me know if the following works. Thanks!
This stored procedure gets a value and increments by 1, but while it does this, I want to lock the table so no other processes can read the same value between the UPDATE and SELECT (of course, this may only happen in a fraction of a second, but I anticipate that we will have thousands of concurrent users). I need to manually increment this column because an identity column is not appropriate in this case.
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I am working on a project which need to produce a sequential certificate number, Everytime I need a new certificate number, I need to find out what is the max number in the database and then the new certificate number just max+1.
But how can I block another
transaction to check what is max certi. number while this transaction is in the middle of writing the new certificate number(max+1) into database . Does ADLockOptimistic work in this case? Here is the code:
My database sql 2000.
cmdTemp.CommandText="Select max(certificateNumber) from product_table where certificateNumber<> 8888888"
cert_info.Open cmdTemp, , AdOpenKeySet, adLockOptimistic
If Not cert_info.EOF then
How can I see which table is locked up by some particular process?
I know that I can view paricular spid from 'current activity'. But is there any way I can see which table is the center of problem?
I really appreciate your help..
We are facing atable lock issue , while running a SSIS package
We have two flows . one for insert and other for update into the same target table.
The update is done using a procedure.
We have disabled the lock table option in the target( in the insert flow)
The first set of records which come for updates flow fine.
But when the records start coming into the insert flow, the data flow stops.
Is this a table lock issue?
How do i set the commit interval at the update flow?
can someone lpease help me out of this situation
Thanka and Regards
I have multiple applications which can potentially update the same trigger simultaneously. Each application:
(1) Reads the contents of the current trigger
(2) Creates a new trigger based on the current contents
(3) Drops the trigger
(4) Creates the new trigger
I need to insure that once one application begins step (1), then no other application can start step (1) until step (4) has completed.
Any ideas on how this can be done? Some databases have a concept of locking tables explicitly, so for them, I can do:
(0) lock table foo;
(1) - (4)
(5) unlock table foo;
Is there such a concept in mysql or is there another way of accomplishing this?
I have an update statement and it looks like it is holding exclusive lock on the table and does not release it until it completes. a PAGLOCK hint has been specified on the update statement and i think it is being ignored. It is a transaction database.so, other queries accessing that table has to wait for it to complete and thus causing timeouts.The Update statement is also causing high IO and CPU utilization. How do I
1) reduce the granularity level to prevent the locking
2)any ideas on optimizing the query?
Here is the query:
SET IndexStart = TMP.IndexStart,
IndexPosition = TMP.IndexStart,
IndexStop = TMP.IndexStop,
IndexLevel = TMP.IndexLevel
FROM Customers AS C WITH (PAGLOCK)
INNER JOIN #tmp_IndexBCs AS TMP WITH (TABLOCKX) ON C.ID= TMP.ID
I use proc handling special business logic (I also use constraints, indexes for that ;-)
Now I have a situation where I should check multiple rows with an proc.
Preventing multi-user issues I want to lock the table (yes, yes potential performance issue, but in this case there are few simultaneous jobs) - in Oracle I could lock the table, but what to do in SQL Server?
Maybe you have an better alternative, then let me hear ;-)
Or should I use "begin transaction"...
Thanks for help
I'm new in SQL and I´ve been the problem bellow:
I lock a record in one foreign table and automaticaly SQL lock the record that matches on primary table.
But this occours just in some primaries tables and not in all. I need that just the table that are of SELECT are lock. How can I do this?
** At open of the invoice:
SET ISOLATION LEVEL READ UNCOMMITTED
SELECT * FROM INVOICE WITH (ROWLOCK UPLOCK) WHERE ( ID = 15 )
******* at the end of invoice:
INSERT INTO INVOICE ........
******* The relationship are:
INVOICE <>> ITENS_INVOICE
ITENS_INVOICE <>> PRODUCTS
CUSTOMER <>> INVOICE
VENDORS <>> INVOICE
Just the INVOICE and PRODUCTS record´s involved in Transaction are lock. ( The CUSTOMER and VENDORS are not locked for example )
But I need that just INVOICE record be locked.
Thank´s for all and sorry my English.
SÃ£o Paulo - Brazil
I want to perform 4 or 5 statements as a transaction but I need to make sure that during this complete transaction no one else inserts or deletes records from a table named SomeTable.
So how can I lock MyTable at the beggining of the transaction so that during my transaction no one else can insert or delete anything in table SomeTable?
I am using Sql Server 2005.
I want to place a LOCK, insert something in the table then return back to the code (with the ID of the inserted item) and then call FUNCTION_A and then based on the outcome of the function I either want to
I want to keep the inserted item and release the lock or
I want to delete the inserted item and release the lock
Any suggestion is greatly appreciated.
To any and all;I have a very large table (16Mil+ records), for which I want to deleteabout 8 Million records. There are a few indexes on this table.Is there a way that I can run either a query or a series of queriesthat will run against each record and delete based on criteria (date)?If I do a single DELETE query, it will take forever, lock the table,and my app that runs against it will stop INSERTING, which is bad.If I do a cursor, I think it locks the table also, so that won't do,right?Any help would be appreciated.Glenn DekhayserContentcatcher.com
I have some questions about locking tables in stored procedures. I got some excellent tips from my last post, but since it's sort of a different problem I figured I'd post it separately.
I have a large log table I need to do manual, periodic clean-up process on, which basically is purging unneccessary log-entries. The idea is to select out the 1-3% I need to another table, drop the old table, and rename the new table to the old one.
The problem is that I most likely will need to lock the entire table while I do all the clean-up stuff. If a client manages to add things inbetween this is going on, I could end up loosing data.
The table looks like this:
LogTypeID -- what category
LogTime -- when it occurred
My imaginary stored procedure looks something like this:
CREATE PROCEDURE ShrinkDB AS
"lock table log" -- do I have to do something like this?
select * into log_keep FROM Log where
logtypeid <> 2020 AND -- activity played
logtypeid <> 5020 AND -- database connected
-- ....etc et..... about 10 different things I don't need to keep
or logtime > dateadd(d, -1, getdate()) -- keep everything from last 24 hours
drop table log
EXEC sp_rename 'log_keep', 'log'
I'm not able to figure out wether I need to run some sort of "Lock" command or not, or if everything inside a stored procedure automatically is locked. If so, I shouldn't worry about loosing any data I guess??
Hopefully it works that way, but if not I assume I'll run into these two problems:
- If a client logs immediately after the Selecet, could data be logged AFTER the select, but BEFORE the drop table-command? In which case I guess I would loose data?
- Immediately after the drop table log in step 3, there's no table named 'log' in my database. 'Log' will be "created" when I run step 4. This means I could perhaps loose data since the client for a brief moment can't log data to the 'log' table?
Hopefully someone can clearify this for me, I've read the documentation, but I don't feel too sure on this subject.... :-)
I need to lock a table in SQL Server. The reason is that I need to insert a value into an identity column (rather than just taking the next sequence number). I have a program that:
1. Sets identity insert on
2. Inserts into the table
3. Sets identity insert off
The problem is that I believe I should lock the table before I turn identity insert on (otherwise, other transactions will fail). I need to ensure that no other operations will take place on the table while I am doing all three of these steps.
I believe I can set the isolation level, but I cannot find any way to establish the lock without executing the update statement itself - which is a nanosecond too late to prevent another user from getting an error.
Open a cursor , Fetch the record ,
during this kind of operation , will the specific table be locked and fail
to be updated or select by another session ?
I currently have a DTS task that is failing on one step due to more locks being allocated than are available.
I therefore changed the step to ensure that a table lock is placed on the table. However, now the step doesn't seem to run at all. The step starts but after waiting for 20 minutes no rows were copied across - whereas before I was experiencing the locking problem that step would take about 2 minutes.
I have since managed to work around this problem by creating a SQL Task that does an insert. This works fine.
I am curious to know why the step was not working with a table lock specified, and was wondering if anyone has come across this before.