May I ask a question about deadlock

小小剑圣

May I ask: If a transaction takes too long from start to end, will other processes generate interlocks when updating or inserting this table? Is there a timeout when selecting this table?
Another question is whether the deadlock is caused by the transaction?

rcloud

Look at the form of your lock. Is it a table lock or a row lock.

lisongfox

Let me give you an example of a deadlock:

-- test environment
USE tempdb
GO
CREATE TABLE t1 (id int)
INSERT t1 VALUES (1)
CREATE TABLE t2 (id int)
INSERT t2 VALUES (2)
GO

-Execute the following statement in query window 1
USE tempdb
GO
BEGIN TRAN
SELECT * FROM t1 WITH (TABLOCKX)
WAITFOR DELAY '00: 00: 10 '
UPDATE t2 SET id = 1
COMMIT TRAN
GO

-Execute the following statement in query window 2
USE tempdb
GO
BEGIN TRAN
SELECT * FROM t2 WITH (TABLOCKX)
WAITFOR DELAY '00: 00: 10 '
UPDATE t1 SET id = 1
COMMIT TRAN
GO


-Delete the test environment after the test is complete
DROP TABLE t1, t2

papaibobo

You should understand what is deadlock and what is blocking? !!

Deadlocks are bound to block, but blocking is not necessarily a deadlock!