Database Administrator

Oracle creates tablespaces and users Oracle creates tablespaces and users 1. Connect to the database# Su-oracle$ Conn/as sysdba 2. Create a tablespaceSQL> create tablespace doiido datafile '/main/oracle/oradata/doiido. dbf' size 1024 M autoextend

Solution to mysql installation failure on Mac, macmysql The version I installed is a mysql-5.6.21-osx10.9-x86_64.dmg that prompts installation failure on Mac OS X 10.10, as shown in. Solution In step 3 of the installation process, select Custom

Oracle CBO evaluates the like data volume, and oraclecbo evaluates like There are two forms of Like Statement, which is evaluated by 5% of the total data volume. SQL> drop table test purge;SQL> create table test as select * from dba_objects; SQL>

Oracle Spool command and oracleSpool command Run the spool command to copy the output results of SQL * plus to a specified file or query the results. Send to the printer and use the spool off command until it is executed.The spool command syntax

Change the version of the dmp file imported from oracle.Today, the customer gave me a table data file exported from the oracle11g database. The file suffix is the dmp file. I imported the dmp file into our business database and reported an error,

SQL assistant-SQL Prompt and SQL assistant promptBackground: When the database design is complex and huge, if we are not very familiar with the script, it will be difficult to complete seemingly simple addition, deletion, modification, and query

Oracle triggers and Oracle triggersOracle triggers A trigger is a special storage process that is automatically triggered by the Oracle system when a database occurs. Triggers are usually used to enhance database integrity constraints and business

SQL optimization -- Logical optimization -- condition simplification, SQL -- 1) query Conditions Query condition concept: In SQL query statements, the expressions used to filter and connect tuples are expressions in the WHERE/JOIN-ON/HAVING

Redis database of 03_NoSQL Database: list type, 03_nosqlredisZookeeper Lists type and Operation List is a linked List structure. The main function room is push, pop, get all values in a range, etc. In the operation, the key is interpreted as the

Oracle get command and Oracleget commandOracle can use the get command to read file content to the buffer zone,The get command syntax is as follows:Get [file] file_name {list | nolist]File_name indicates an external file, which is included in the

Mysql and Oracle Database concat () functions, oracleconcat I. Different Function Parameters Mysql supports concatenation of multiple strings: CONCAT (str1, str2 ,...) Oralce only supports concatenation of two strings. To splice multiple strings,

Hive exception: UDFArgumentTypeException No argument is expected, argumentexpected Background: Run hivesql in a market today. SQL is normal and there is no problem in data warehouse execution. However, after running in a market, the system always

In Linux, mysql forgets the root user password, and mysqlrootToday, when receiving a MYSQL server, I found that I forgot the password of the root user of MYSQL. I found that no root user password exists in various documents. Therefore, I need to

Oracle SQL optimization set and oraclesql Optimization **************************************** * ******************** 1. create an optimization set object ************************************ * ********************** --- authorize grant administer

Oracle fails to get the index result due to an error. oracle does not get the index. There is a script that has been running for a long time and does not produce any results immediately after optimization. The original statement is as follows: SQL>

In Linux, Mysql table names are case-insensitive and mysql is case-insensitive.Scenario: Recently, the company switched the database from Oracle to Mysql. Since the table names in Oracle are case insensitive, the problem of table names not found in

Mysql Common commands (Baidu Library download, please forget) 1. Connect to MySQLFormat: mysql-h host address-u user name-p User Password1. Example 1: connect to MYSQL on the local machine.First, open the DOS window, enter the directory mysqlbin,

Kettle connection Cluster Environment configuration, kettle Cluster Environment Original Works are from the blog of "Deep Blue blog". You are welcome to reprint them. Please note the following source when reprinting them. Otherwise, you will be held

Mysql client data garbled, mysql client garbled Garbled characters appear when inserting Chinese data into mysql: Mysql> select * from test;+ ------ + ----------- +| Id | name |+ ------ + ----------- +| 1 | why does one fail? || 2 | too many threads?

T_ SQL rowtype, t_sqlrowtype T-SQL formats: Declare Statement Begin Processing End -- complete   Nvl function nvl (string, value ); Returns a string if the string is not empty. Returns the value if the string is null.   Enter a job