Tagged Questions

1
vote
0answers
33 views

Does SQL Server place shared locks on scanned records when using REPEATABLE READ [duplicate]

Assume a SQLCmd session which is using transaction isolation level REPEATABLE READ. In this session I start a transaction and execute an UPDATE statement with a WHERE clause on a non indexed column. ...
0
votes
0answers
47 views

What would this non-'unique index with a unique search condition` query lock?

I am not sure about this part of the transaction manual For locking reads (SELECT with FOR UPDATE or LOCK IN SHARE MODE), UPDATE, and DELETE statements, locking depends on whether the statement ...
0
votes
1answer
55 views

Do I need a locking read?

I am inserting rows in a table, based on a value and on the existence of a row, which I get from SELECT statements. This function can be run concurrently, so I need to do some extra obviously. The ...
2
votes
0answers
714 views

Table Lock on INSERT - How to optimize

we have a few long running procedures in the database, that cause an instant Table Lock on our main text storage table, which causes all other requests of the web app to wait (because the table is ...
0
votes
0answers
86 views

Being careful about additional records being added in a duplicate record merge?

We have a multi-user MS-Access 2003 database. Connecting to it using SQuirrel SQL, and the JDBC/ODBC bridge, I've managed to eek transactions of some sort out of JET by turning off autocommit. I've ...
3
votes
1answer
138 views

SQL Server : KEY lock prevents FK on nearby row, but not SELECT [closed]

I have the following table structure (simplified, pseudocode): TABLE dbo.Users (Id int NOT NULL IDENTITY PRIMARY KEY) TABLE dbo.Transfers ( Id int NOT NULL IDENTITY PRIMARY KEY, ...
2
votes
1answer
305 views

In InnoDB, does a Transaction imply any implicit locking of a table?

The Isolation level is REPEATABLE_READ. The logic is as under: Transaction begins Read data from Table A If (Table A has Any Data) End Transaction and exit If Table A has No Data, Proceed further ...
1
vote
2answers
136 views

INSERT statements in a transaction and locking a range of rows

I have a table that is concurrently accessed by many users. Typically, INSERTs to the table are made one at a time. Occassionaly, users will add a "batch" of rows at the same time. The batch is ...
3
votes
2answers
4k views

SQL Server Transaction Timeout

Is there a way in SQL Server 2008 R2 to cause a timeout for a database modification involving a transaction? We have a scenario where our application code hangs or throws an exception and fails to ...
3
votes
1answer
196 views

Does blocking always mean open transaction?

This may seem a bit dull question but does blocking always mean that there is open transaction and that may cause transaction log grow to infinity because open transaction prevents log truncation ...
5
votes
3answers
1k views

SQL Server - what isolation level for non-blocking select statements?

I have a long running transaction (called, say, T1) that performs some deletes, updates and inserts on a table in SQL Server 2008 R2. At the same time, another process periodically runs select ...
2
votes
1answer
358 views

Locking, deadlocking workaround while process data at the same table

My database has a table: tableX. Task1 makes intensive INSERTs (1000 records per minute) as records to process and very seldom UPDATEs (1-2 records per minute) as records to recalculate. At the ...