Database Administrator

How can I close an Oracle database? The following describes the three most common methods for shutting down an Oracle database. 1. Close normally The option used to close the database normally is normal. Before the database is closed, all

Problem: The input floating point number and decimal place, Input output ---------------- 0.123 0.12 .. 123 0.12 . 1 0.10 .. 199 0.20 123.199 123.1990 Solution: Create table test_t ( Col_1 number (3, 2 ), Col_2 number (7, 4) );

1. view the tablespace size and maximum value of undo.Select t. file_name, t. tablespace_name,T. bytes/1024/1024/1024 "GB", t. maxbytes/1024/1024/1024 "Max GB"From dba_data_files t where t. tablespace_name = 'undotbs1'Data

Problem description: an error is reported when the client connects to the database. ORA-12516: TNS: Listeners cannot find available handles matching protocol stacks Solution Process: 1. Check the current session count, processes, and sessions values,

1. Transaction concept:Concept: transactions in databases are logical units of work. A transaction is composed of one or more SQL statements that complete a group of related behaviors, the transaction mechanism is used to ensure that the operations

Due to accidental deletion of Oracle table data, the data may be very important. How to quickly restore the data so that the supervisor does not discover it can write a stored procedure to restore the data at the previous time of data

// Let's take a look at the authorized binary tree below. The actual point is a diagram (complex diagram ):Sys/\Test001 (dba) test002 (dba)/\\T1 t2 t3--// As shown in the preceding Binary Tree, assume that both test001 and test002 are granted dba

1. First install a Library: Sudo apt-cache search libaioSudo apt-get install libaio-dev 2. Add users and user groups after installation: Sudo groupadd mysqlSudo useradd-r-g mysql 3. decompress the mysql package: Cd localSudo tar zvfx service1/mysql-5

When testing Oracle, I would like to test the performance of using asynchronous IO. But asynchronous IO requires special configuration, otherwise, it is easy to encounter a very famous "ORA-01578: ORACLE data block parallel upted (file #202, block #2

Checking Network Configuration Requirements... Check complete. The overall result of this check is: not executed I checked it on the Internet and many of my friends encountered this problem, but it was easy to solve it. You only need to install

In JUnit, foreign keys are generally not required. However, the foreign key has been created during the database generation process, which is troublesome for adding, deleting, and modifying data. Follow these steps to invalidate or take effect of

Use an Oracle user to access the database Sqlplus/nologConn/as sysdba1. Create a userCreate User orcldba Identified by zcs001; 2. Create a roleCreate role orclrole; 3. Authorize a roleGrant create session to orclrole;Grant select on v _ $ sysstat to

1. SQL statement 1: -- 1. view the table space name and size. SELECT t. tablespace_name, round (SUM (bytes/(1024*1024), 0) ts_size FROM dba_tablespaces t, dba_data_files d WHERE t. tablespace_name = d. tablespace_name Group by t.

1. Automatic Backup You can use the exp method (provided that you have the export permission) and write a script for the operating system. If you have a windows system, you can write a bat file and use exp to export it, then, add BAT to the

[DDL] Create table Alter table Drop table delete table Truncate table delete all rows in the table Create index Drop index Delete index When a DDL statement is executed, Oracle submits the current transaction before and after each statement.

Lv_ SQL: ='Insert into ETL_SUCESS_AMOUNTSelect SEQ_ OS _ETL_AMOUNTID.NEXTVAL AS AMOUNTID, 1, AMOUNT_DATA, AMOUNT_HOUR,Serviceid, portalid, mouduleid, actionid, RESERVE1_ID, RESERVE2_ID, RESERVE3_ID,RESERVE4_ID, AMOUNT, AMOUNT_TIMEFrom(SelectTrunc

1. Install the instantclient package: Instantclient-basic-linux-x86-64-11.2.0.2.0.zip Basic Package The instantclient-sdk-linux-x86-64-11.2.0.2.0.zip connects to the db using c or perl Instantclient-sqlplus-linux-x86-64-11.2.0.2.0.zip sqlplus 2.

A simple method for automatic backup of Oracle databases. Write a batch. The content is as follows: Echo ***** backup start ...******** SetFname = D: \ databak \ %Date:~ 0, 10% Exp system/password @ orcl file = % fname %. dmp owner =

Oracle does not have a hexadecimal to binary function. For ease of work, I wrote Create or replace function hex_to_bin (hex varchar2) return varchar2 isV_hex varchar2 (10000 );V_len number;V_var varchar2 (10000 );V_result varchar2 (10000): =

SQL>Select*FromT; IDNAMESCORE ------------------------------ 3. smith 100 4. smith 100 5 jerry 80 6 tom 80 1. evan 100 2 evan 100 Seven evan 100 You have selected 7 rows. SQL> ed tmp. buf SQL>-- Obtain all records, but names and