Database Administrator

Recent field feedback: a messaging program accessing the Oracle database records some error logs about "ORA-00060: deadlock detected while waiting for resources. However, after the communication program record is abnormal, it does not crash and can

1. Modify the DBSNMP password: To reconfigure the DBCONSOLE, you need to enter the DBSNMP password, but any password will display an error and must be modified in advance. SQL> alter user dbsnmp identified by xxx; 2. delete users created on the

V $ database: database information, such as the database name and creation time. V $ instance information, such as instance name and start time. V $ parameter information, select * from v $ parameter where name like '% name' ----> show parameter

Hibernate includes 23 jar packages, which are dazzling. This article will explain in detail the role of each jar package in Hibernate, so that you can choose based on your own needs in the application. Download Hibernate, for example, the stable

A properly configured Mongodb sharding cluster does not have a single point of failure.This article describes several potential node failure scenarios in a sharded cluster and how Mongodb handles these node faults. 1. Mongos node downA Mongos

Org. springframework. beans. factory. beanCreationException: Error creating bean with name 'sessionfactory 'defined in ServletContext resource [/WEB-INF/config/applicationContext. xml]: Invocation of init method failed; nested exception is org.

Building an Oracle two-way stream replication is a very complicated process. The purpose of writing this document is to list what needs to be done in an organized manner as much as possible to help DBAs build a stream replication environment more

When the data block in the buffer cache is modified, the server process generates redo data and writes it to the redo log buffer. When the following conditions are met, LGWR will write the entries in the redo log buffer into the online redo log:--

1. spring manages hiberante transactions. When setting the cut plane, you must consider all the places that may involve transactions. Otherwise, the cut plane does not involve any database operations, which occupy a lot of resources and cannot be

I wonder why the ASM instance created with DBCA cannot be started. Manual start SQL> startupORA-01078: failure in processing system parametersLRM-00109: cocould not open parameter file '/opt/Oracle/product/10.2.0/db_1/dbs/init + ASM.

1. Mongo objectA connection pool is implemented internally. Mongo objects are thread-safe. Therefore, you can create only one Mongo object and use it safely in a multi-threaded environment. Therefore, we can use the Mongo variable as a member

Super User problems: Use admin # Adding or modifying user passwords Db. addUser ('admin', 'pwd ') # Viewing the user list Db. system. users. find () # User Authentication Db. auth ('admin', 'pwd ') # Deleting a user Db. removeUser

1. To enable Python to operate the MySQL database, first install the MySQL-python package. You can run the following command on CentOS to install the package: [Python] $ Sudo yum install MySQL-python 2. Leave nothing to say. Take two steps. The

71. your database instance is started using the server parameter file (SPFILE ). control files are multiplexed and stored on different disks. because of a disk failure, you lost one of these control files. you replaced the damaged disk. what is the

MyISAM is the default storage engine for MySQL. Each table supports a maximum of _ 4.295E + 09 records and 64 index fields. The two may be larger for different versions. MyISAM also supports full-Text indexing of Text/Blo fields. The tables and

In the project test, the tester finds that when the query result list is displayed on multiple pages, some data is repeatedly displayed on several pages, and some are not displayed at one time. After analyzing the SQL, the original problem lies in

Oracle redo online Log File reconstruction in seven steps redo online log reconstruction in five minutes redo log Reconstruction Step 1: create three new online log groups: ALTER DATABASE ADDLOGFILEGROUP4

1: An error occurred while restarting the database today: SQL> startup mountORA-03113: end-of-file on communication channel Take a look at alert. log:...PMON started with pid = 2, OS id = 7359PSP0 started with pid = 3, OS id = 7361MMAN started with

Oracle 10 Gb provides two activation methods, one for users and the other for tables. Implementation Method for users: DBMS_STATS.ALTER_SCHEMA_TABLE_MONITORING ( Ownname VARCHAR2DEFAULT NULL, Monitoring BOOLEANDEFAULT TRUE); How to implement a

Processing of date functionsIf you are uncomfortable with the date format of the current system, you can modify the display format of the current session.Idle> alter session set NLS_DATE_FORMAT = 'yyyy-MM-DD HH24: MI: ss '; Session altered. Idle>