rollback

Data Buffer Hit ratio# The hit rate of the data block in the data buffer, usually should be above 90%, otherwise consider increase db_block_buffers (9i above but db_cache_size) Buffer nowait ratio# The wait rate in the buffer to get buffer

oracle| Recovery | data | database | Optimization The steps to minimize Oracle downtime are discussed here. All forms of downtime-planned or unplanned-always occur, and a DBA should have the right backup strategy so that it can recover more quickly

Server Why should I introduce a lock? Concurrent operations on a database by multiple users can cause the following data inconsistencies: Missing updatesA,b two users read the same data and make changes, one of the user's changes to destroy the

Recently a friend asked me, he said that he deleted millions of to tens of millions of data in SQL Server is very slow, to help him analyze, some of the following comments, perhaps useful for many people, and also good long did not write a blog,

Program | Data first, CREATE database Database name: Nhibernate Use NHibernate Go CREATE TABLE Users ( LogonId nvarchar not NULL default ' 0 ', Name nvarchar default NULL, Password nvarchar () default NULL, EmailAddress nvarchar () default

oracle| Data | database 1, view the table space name and size Set linesize 140;set pages 200;column tablespace_name format A30;select tablespace_name,min_extents,max_extents,pct_ Increase,status from Dba_tablespaces;select

Application Purpose ======= The purpose of this article are to provide a understanding of freelists and freelist. SCOPE & Application =================== This article was intended to being used by DBAs to help understand the how freelists and

Oracle Unfortunately encountered undo corruption in operation, of course, the best way is full recovery, but if there is no backup in the case of undo damage how to do? The following is for you to introduce the solution to this situation, the need

Choosing Proper Innodb_log_file_size Choose the right Innodb_log_file_size If you are doing significant amount of writes to Innodb tables decent size of innodb_log_file_size are important for MySQL P Erformance. However setting it too large would

How many times have you encountered the error message "sql0946c The transaction log for the"? When trying to solve the problem, do you stop to think about why the transaction log and the transaction logging service are intended? Without

oracle| Data | database Original Author: Sameer Wadhwa Pause (quiescing) A database is a powerful new feature that allows DBAs to complete some of the operations that a database is in restricted mode (restricted modes). With this feature, the DBA

What is redo Redo record transaction logs, divided into online and archived. For the purpose of recovery. For example, if the machine is out of power, then you need to go online redo logs to restore the system to the failure point after the reboot.

A few days ago, my colleague called to say that the company's development bank died 4 or 5 times a day. I just got back to the company today. Check Alertlog and find hundreds of errors, all of which are: Errors in file

1. Introduction Using migration in rails makes it easy to manage the structure of your database. You can create databases, create tables, delete tables, add fields, delete fields, and organize your data. Migration is a series of classes, all of

/// Backup and restore operations on the database, SQL statement implementation/// Implementing SQL statements for backup or recovery Whether the operation is a backup operation, true or False private void Bakreductsql (string cmdtext,bool

Oracle ALTER DATABASE datafile ' D:\ORANT\DATABASE\USER1ORCL. ORA ' RESIZE 1000M; CREATE tablespace index_data datafile ' D:\ORANT\DATABASE\INDEX_DATA ' SIZE 500M; ALTER DATABASE datafile ' D:\ORANT\DATABASE\RBS1ORCL. ORA ' RESIZE 300M; ALTER

Stored Procedures A BT director's request on duty management requirements are as follows 11 Group of Queues n Individuals, there are 4 roles, leaders, men, aunts, drivers. n Individuals line up in order according to their roles. 2 on duty: Monday

Transaction processing is one of the most important problems to be solved in enterprise application. Java EE provides complete transaction management capabilities through JTA, including the ability to manage multiple transactional resources. But

Why the introduction of transactional concepts The transaction is the concurrent control mechanism commonly used in the current mainstream database system. What is a transaction Transactions have the following 4 most important characteristics, which

In programming, you often need to use transactions. A business is a series of operations that must be successful, and all other steps must be undone as long as one operation fails. For example, using ASP to develop a network hard disk system, the