![]() Problems occur when blocking is sustained for a longer period of time, as this leads to slower transactions. On a well optimised system, it can be hard to notice and doesn’t cause problems. In fact, it is vital to maintain ACID transactions. Again, there are exceptions to these based on the isolation level used.īlocking then is a perfectly natural occurrence within SQL Server. Similarly, data being read blocks data from being modified. In the scenario where a row is being updated, the lock type of IX or X means that a simultaneous read operation will be blocked until the data modification lock has been released. You need to have locks in order to have blocking. If data is being modified, the select query will have to wait on acquiring the shared lock it needs to read data.īlocking is the real world impact of locks being taken on resources and other lock types being requested which are incompatible with the existing lock.This behaviour changes however if a higher isolation level such as serializable is being used. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |