Database Administrator

Oracle 11g cannot export empty tables in multiple ways Oracle 11g empty table cannot be exported: Data Query shows a new feature in Oracle 11G: The new parameter "deferred_segment_creation" indicates that the segment delay is created. The default

MySQL query optimization: profile function MySQL query optimization: profile function. Note that you need to install the profile module. 1. The version is later than 5.0.37. (Show profiles and show profile were added in MySQL 5.0.37 .) SELECT @

Oracle Database high-risk vulnerability warning! Users have recently exposed an Oracle high-risk vulnerability on the Internet. Users with only query permissions can add, delete, and modify data, which is very dangerous. This vulnerability has a

Flash back archive (11G new feature) Stay away from ORA-01555 errors 1.1.1.1 flash back Archiving The previous flash back is implemented based on undo flash back, because our flash back is not sure of time, so it will lead to ORA-01555 (snapshot is

Diagnosis and repair of a rac vip drift Background The customer's 10 Gb database VIP is down, causing VIP load to another node Event support details 04:29:56. went OFFLINE unexpectedly occurs in the VIP of machine 1 of 378. Check the cause of VIP

Table creation statement under the name of Oracle Scott We often use data for testing when learning Oracle, so it is necessary to create tables and data. Create table EMP(Empno number (4) primary key,ENAME VARCHAR2 (10 ),JOB VARCHAR2 (9 ),Mgr number

Simulation of rm-rf *. dbf recovery in cold backup Backup recovery has always been a major concern for all relational databases. The following describes the Cold Standby database, simulates and destroys data files to restore the database, and

Crontab-caused frequent email sending This afternoon, the customer sent an email to report that emails for file system monitoring and table space usage in a certain environment were frequently received, and they felt that they were sent once an hour,

ORA-00911: Invalid character resolved Today, I helped my colleagues call a stored procedure. The storage process is long and the problem occurs in a piece of code similar to the following. BEGIN Execute immediate 'update' | v_table_name | 'set' |

Some suggestions for Mysql to write high-quality SQL statements: mysqlsql CleverCode has written some inefficient SQL statements in actual work. These statements put a lot of pressure on the database. The most important manifestation is that SQL

Oracle basics-Introduction (first meeting) and oracle first meetingI. Overall introduction: Oracle databases and databases represent the basis of all Oracle database objects. Oracle is a large-scale relational database based on advanced Structured

When deduplication is, temporary processing is disabled, and 80 Original Works are from the blog of "Deep Blue blog". You are welcome to repost them. Please indicate the source when you repost them. Otherwise, the copyright will be held legally

Freeze file header, freezefileheaderSQL> select * from v $ version where rownum = 1;BANNER--------------------------------------------------------------------------------Oracle Database 11g Enterprise Edition Release 11.2.0.1.0-ProductionWe can use

Mysql cascade operations (instances) and mysql-level operation instances MySQL only supports the InnoDB Storage engine for Foreign keys. When creating foreign keys, the parent table must have corresponding indexes, when a sub-Table creates a

Data structure, data structure and AlgorithmSearch This article mainly discusses various methods for searching ordered tables, ordered tables, index tables, and hash tables, as well as the average length of the corresponding searching methods in the

Data structure, data structure and AlgorithmBasic concepts of queue 1. Basic concepts of queueQueue: it is also a linear table with limited operations. It is a linear table of First In First Out (FIFO. You can only insert at one end of the table and

SQL Application and Development: (7) Data Operations · query · (1) Regular and regular SQL Databases are created to facilitate the effective management of information. people hope that the database can provide the required data information at any

Six major differences between InnoDB and Myisam: six major innodbmyisam MyISAM InnoDB Differences in composition: Each MyISAM is stored as three files on the disk. The name of the first file starts with the name of the table.

CBO estimates three items that need to be referenced in the execution plan.Estimator The estimator determines the overall cost of a given execution plan. The estimator generates three different types of measures to achieve this goal:

Precautions for modifying the operating system on the Oracle Database Server Precautions for modifying the operating system on the Oracle database server: For standalone or ha1. There is no impact on the database itself. Because scn does not