nolock

Using WITH(NOLOCK) to increase performance

由 天大地大妈咪最大 提交于 2019-12-24 12:51:57
问题 I have seen developers using WITH(nolock) in the query, is there any disadvantage of it? Also, what is the default mode of execution of query? My database do not have any index. Is there any other way to increase database select statement performance? 回答1: The common misconception with nolock is that that it places no locks on the database whilst executing. Technically it does issues a schema-stability (sch-s) lock, so the 'no' part of the lock relates to the data side of the query. Most of

How perform lockmode:none on associations (join) with Doctrine2 and SQL Server

由 隐身守侯 提交于 2019-12-22 12:38:14
问题 I'm trying to append the With(nolock) hint to my Queries using Doctrine2. I tried using the ->setLockMode(LockMode::NONE)->getSQL(); but it didn't work as expected, it added the WITH(NOLOCK) just to the ( first ) table in the FROM clause. I'll explain: $dql='SELECT e, o FROM Porject:Example e JOIN e.owner o'; $query = $this->getEntityManager()->createQuery($dql); try{ $this->getEntityManager()->getConnection()->beginTransaction(); $result = $query ->setLockMode(LockMode::NONE)->getSQL();

How can I avoid a deadlock between these two SQL statements?

由 别等时光非礼了梦想. 提交于 2019-12-21 04:57:11
问题 I have two stored procedures running in separate threads, running on SQL Server 2005. One procedure inserts new rows into a set of tables and the other procedure deletes old data from the same set of tables. These procedures are running into a deadlock on the tables DLevel and Model . Here is the schema: (source: barramsoft.com) Table DFile : Primary Key = DFileID Table DLevel : Primary Key = DLevelID, Foreign Key: DFileID Table Model : Primary Key = ModelID, Foreign Key: DFileID Table

Java Hibernate HQL queries with nolock

由 冷暖自知 提交于 2019-12-20 12:35:34
问题 Is there a way to run these queries as if I added a (NOLOCK) hint to them? 回答1: If you really need this, then you want to do something like: session.connection().setTransactionIsolation(Connection.TRANSACTION_READ_UNCOMMITTED); which is identical to a nolock. Before you do that, really think carefully if you want to do a dirty read. Most of the time people do this because it's what they've always done, rather than because it's the right thing to do. In particular, this does not work well with

Using NOLOCK Hint in EF4?

由 夙愿已清 提交于 2019-12-17 07:34:34
问题 We're evaluating EF4 and my DBA says we must use the NOLOCK hint in all our SELECT statements. So I'm looking into how to make this happen when using EF4. I've read the different ideas on how to make this happen in EF4, but all seem like a work around and not sanctioned by Microsoft or EF4. What is the "official Microsoft" response to someone who wants their SELECT statement(s) to include the NOLOCK hint when using LINQ-to-SQL / LINQ-to-Entities and EF4? By the way, the absolute best

Remote table-Valued Function Calls are not allowed

由 こ雲淡風輕ζ 提交于 2019-12-10 00:38:16
问题 How can I make this work?Im running a table valued function from a remote linked server. i tried adding no lock to this 4 part naming but still i get the same error. Im using mssql-2008 select * from [110.10.10.100].testdbname.dbo.ufn_getdata('4/25/2013') as tb;(NOLOCK) 回答1: You need to add WITH (NOLOCK) . Not entirely sure why but I just ran into this issue today and this solved my issue. SELECT * FROM [110.10.10.100].testdbname.dbo.ufn_getdata('4/25/2013') AS tb WITH (NOLOCK); 回答2: Nolock

MS SQL Server 2008 “with (nolock)” equivalent for IBM DB2 9.7

由 六月ゝ 毕业季﹏ 提交于 2019-12-08 19:13:59
问题 In MS SQL Server 2008 you can write like this: FROM EMPLOYEE as A with (nolock) Is there an equivalent syntax for DB2 9.7? Thanks 回答1: DB2: Uncomitted Read = WITH UR SELECT * FROM whatevertable WITH UR 来源： https://stackoverflow.com/questions/19629299/ms-sql-server-2008-with-nolock-equivalent-for-ibm-db2-9-7

Remote table-Valued Function Calls are not allowed

由 爷，独闯天下 提交于 2019-12-04 23:40:35
How can I make this work?Im running a table valued function from a remote linked server. i tried adding no lock to this 4 part naming but still i get the same error. Im using mssql-2008 select * from [110.10.10.100].testdbname.dbo.ufn_getdata('4/25/2013') as tb;(NOLOCK) You need to add WITH (NOLOCK) . Not entirely sure why but I just ran into this issue today and this solved my issue. SELECT * FROM [110.10.10.100].testdbname.dbo.ufn_getdata('4/25/2013') AS tb WITH (NOLOCK); Nolock doesn't work for me. However, using OPENQUERY does... Replace DMS_DB.dbo.tfu_V_DMS_Desktop(''de'')' with [110.10

PostgreSQL Equivalent of SQLServer's NoLock Hint

由 为君一笑 提交于 2019-12-04 14:59:57
问题 In SQLServer, you can use syntax "(nolock)" to ensure the query doesn't lock the table or isn't blocked by other queries locking the same table. e.g. SELECT * FROM mytable (nolock) WHERE id = blah What's the equivalent syntax in Postgres? I found some documentation on table locking in PG (http://www.postgresql.org/docs/8.1/interactive/sql-lock.html), but it all seems geared at how to lock a table, not ensure it's not locked . 回答1: A SELECT doesn't lock any table in PostgreSQL, unless you want

with(nolock) or (nolock) - Is there a difference?

由 偶尔善良 提交于 2019-12-04 14:58:11
问题 Everything is based on the assumption that with(nolock) is entirely appropriate for the situtation. There are already plenty of questions out there debating whether or not to use with(nolock). I've looked around and haven't been able to find if there is an actual difference between using with(nolock) : select customer, zipcode from customers c with(nolock) or just (nolock) : select customer, zipcode from customers c (nolock) Is there a functional difference between the two? Stylistic? Is one
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