Database Administrator

Configure RMAN to delete archive logs that have been applied to the standby Database In DataGuard configuration, sometimes we need to use RMAN to automatically delete archive logs that have been applied to the slave database from FRA. When the

Will MySQL secondary indexes automatically complete the primary key? At the beginning: I have been skeptical about whether MySQL secondary indexes are automatically added to the primary key. Today I have analyzed 5.5 and 5.6

Performance impact of Delete on table data deletionAs mentioned in the previous article (), when we use delete to delete data, because the high water level cannot be lowered, a full table scan will cause database performance problems, the truncate

After Oracle 11gR2 RAC is restarted, only one node can be started. Problem Background: After the normal deployment of Oracle 11gR2 RAC is complete, perform the two-node restart operation to find that the cluster resources of one of the nodes cannot

B-Tree indexes are superior to BitMap indexes. 1. Experiment description: Operating System: rhel 5.4x86 Database: Oracle 11g R2 Lab Description: This experiment aims to demonstrate that the B-Tree index performance is superior to the BitMap

MySQL master-slave replication asynchronous semi-sync instance MySQL master-slave replication asynchronous semi-sync instance Create mysql ReplicationNode1:Mysql> show master status;+ ------------------ + ---------- + -------------- + -------------

Implement MapReduce in Oracle Database When programmers develop parallel programs, the Map-Reduce mode is becoming popular. These map-reduce programs usually process large amounts of data in parallel. This article demonstrates how to implement the

Binary installation MySQL-5.7.4 Database MySQL 5.7.4 significantly improves query performance, which is doubled from MySQL 5.6. On the test platform, it can reach 512000 read-only QPS per second, while MySQL 5.6 can only reach 250000 QPS. This

MySQL user and permission management The main function of the MySQL permission system is to verify the user connected to a given host and grant the user the related DML and DQL permissions on the database. MySQL access control involves two phases:

Start the database and start the oracle database Database STARTUP (STARTUP) Three steps are required to start a database: 1. Create an Oracle instance (not in the installation phase) 2. Database Installation By instance (installation phase) 3. Open

Delete duplicate dataDelete from cbe_subscriberWhere rowid! = (Select max (rowid)From cbe_subscriber BWhere a. SUBSCRIBERKEY = B. SUBSCRIBERKEYAnd a. APPLYTIME = B. APPLYTIME );ORACLE deletes duplicate data I have already tried it. [Line ].Delete

Bcnf paradigm, bcnf 3.5 paradigm -- what is the bcnf paradigm? For the bcnf paradigm, my understanding through reading materials is -- Removing primary key dependencies. For example, a warehouse management table has the following attributes

RAC background process introduction, rac background processThere are more processes on the RAC database than on a single instance database. These processes are unique to RAC and are set to implement cluster database functions. This article will

Adjust the redo log file size in oracle rac, racredoAdjust the size of the redo log file under rac(1) view the current log information:Select * from v $ logfile;(The path in step 2 can be seen in the MEMBER column here. The redo file name is named

VB. NET and SQL databases, and VB. NETsql Databases Data contains rich information. Data is a resource. The connection operations to SQL databases are slightly different for different languages due to their respective syntax features. However, the

Wang Liping -- Differences Between ContentValues, HashTable, and HashMap, hashmaphashtable ContentValues: A storage mechanism, key-value Feature: key can only be of the string type, and value can only be of the basic type, not an object. Application:

Small oracle-imp import error filesize settings, oracle-impfilesize **************************************** ******************************** *************************************** Original Works are from the blog of "Deep Blue blog". You are

T-SQL templates defined by common SQL jobs, sqlt-SQL templates -- Define the creation job DECLARE @ jobid uniqueidentifierEXEC msdb. dbo. sp_add_job @ job_name = n' job name', @ job_id = @ jobid OUTPUT -- Define job steps DECLARE @ SQL nvarchar (400)

MySql Backup Recovery and mysql Backup Recovery Mysql backup restoration method We generally perform the following operations to back up and restore mysql databases (generally from dozens to hundreds of GB) to windows machines, then, the files on

MongoDB operation manual CRUD query pointer, mongodbcrudEnumeration traversal pointer Overview As mentioned earlier, if db. collection. find () is not specified to a variable declared by var, the first 20 records will be automatically