Oracle

Today, I made a serious mistake at work: I got rid of the data in the Oracle database used by our system! When I found myself correct, I suddenly burst into a cold sweat. However, if we do not back up the database on a regular basis and recover the

Usage 1: Can indexed queries improve query performance? Instance Enumeration 2: What are the first, second, and third paradigms of database design and BCNF? 3: What is the difference between StoreProcedure and Function? 4: how to track the SQL of a

When I started my database today, I found that the database can only be mounted and cannot be opened. The following error message is displayed: SQL> select open_mode from v $ database; OPEN_MODE----------MOUNTED SQL> alter database open;Alter

1. inner connection (natural connection) 2. External Connection (1) left Outer Join (the table on the left is not restricted) (2) Right Outer Join (the table on the right is not restricted) (3) Full outer join (no restrictions are imposed on both

ORACLE1. query related informationSELECT * FROM USER_TABLESSELECT * FROM USER_INDEXES;2. Modify Table Structure Information* Alter table SCHEMA_NAME.TABLE_NAME move tablespace ttprddata storage (INITIAL 64 K)3. Modify the index structure information*

Oracle index problems are often encountered when learning Oracle. Here we will introduce the solutions to Oracle index problems. Oracle indexes and corresponding tables should be in different tablespaces. Oracle can read data on different hard disks

7.1 What is redo logThe most critical part of the recovery operation is redo logs, which include two or more pre-allocated files to store all the changes in the database. Each database process is associated with the redo log to prevent instance

Today, I received a confirmation request from the development team. The following three statements have the same execution plan COST, but the actual execution results differ greatly (1) the query speed is very slow, 2) and 3 ).  1)Select *From

Query table structure Report "ORA-04043: Object XXX does not exist" Solve the Problem of Oracle 11.2.0 + SQL Plus + PowerDesigner 15.1 This semester to learn Oracle database application technology, need to do a course design. PowerDesigner exports

About Oracle 11gR2 Grid Infrastructure Single Client Access Name (SCAN) Oracle11gR2Grid Infrastructure (CRS) introduces Single Client Access Name (SCAN) to simplify Client Access to database services, this article describes in detail the meaning and

When filtering duplicate records in Oracle for data processing, it is often the case that there are multiple records in the database, some of which have the same field value and other fields have different values. in this case, only one data record

Learn about oralce and what to write 1. query statement select * from TF_ B _TERM_PREPMG_LOG; select * from TD_M_TERM_PRICE; select * from TF_ B _CEN_TERM_MANAGER_LOG, Region; // query select * from region together with two tables; select * from TF_

Oracle SQL loader Use Cases Listing 1: ---------------------- dir *. csvtype abc.csv sqlplus scott/tiger @ orclcreate table emp1 (name varchar2 (80), salary number); hostnotepad abc. ctlload datainfile abc.csv into table emp fields terminated by ',

Oracle functions interview question 1. What are the functions for string operations? Answer: ASCII ()-the function returns the ASCII code value CHR () of the leftmost character of the character expression-the function is used to convert the ASCII

ORCLE to export a large amount of data to txt Method 1: Use the SQLPlus spool command operation step 1. Create a script file and store it, such as D: \ spool. SQL. The specific code is as follows: SQL code set echo off -- when you use the start

PLSQL garbled & TNS-12557: protocol adapter not loadable solves 1. garbled is a character set problem. Set NLS_LANG = SIMPLIFIED CHINESE_CHINA.ZHS16GBK  Or Set NLS_LANG = AMERICAN_AMERICA.UTF8  Yes. 2. I encountered a link to TNS-12557: protocol

The higher the level of the six major ORACLE lock modes, the more impact the ORACLE locks have the following modes: 0: none1: null 2: Row-S Row sharing (RS): Share table lock, sub Branch 3: Row-X exclusive (RX): used for Row modification, sub

Example of oracle expdp and impdp: due to production requirements, you need to copy the rmtel user data to rmtel_xzy, but exclude the rmtel user ('cab _ JJXPORT_TAB ', 't_servicexx', 'tb _ crossconnection', 'tb _ link', 'tb _ card', 'tb _

[Oracle] Data Pump detailed tutorial (2)-expdp [Oracle] Data Pump detailed tutorial (1)-Overview http://www.bkjia.com/database/201307/230385.html The export mode has the following five export modes, which are mutually exclusive and cannot be used at

ORA-00845 ORACLE11G common shm problem error process srv-bioradb:~> sqlplus / as sysdbaSQL*Plus: Release 11.2.0.3.0 Production on Thu Jul 25 18:27:45 2013Copyright (c) 1982, 2011, Oracle. All rights reserved.Connected to an idle instance.SQL>