Database Administrator

Due to the lock mechanism, when execution of a DML or ddl SQL statement is blocked, you need to find out why the SQL statement is blocked. The following describes the common diagnostic methods: Suppose there is a table: table t (id int primary key,

Whether we use dbca for database creation or manual creation. After the database creation task is completed, three parameters are very important for future production and use. Generally, we need to open them.The first one is log_checkpoints_to_alert.

Step 1:Create two directories C: \ mwagui \ lib and C: \ mwagui \ log, and download patch: 4205328 (Mobile Wireless Applications (MWA) j2-telnet GUI Client 11.5.10) to C: \ mwagui \ lib.(Patch: 4205328 has a zip file containing the java

Environment:OS: Red Hat Linux As 5DB: Oracle 10.2.0.4 Generally, the character set is selected during installation. to modify the character set of the database, we recommend that you recreate the database (EXP/EXPDP export before importing ),

Oracle 11g provides new row and column conversion operations: Convert (row to column) and unconvert column to row. This document describes the unregister function. The existing table src_table is as follows: Product_Id (product ID)

1. Environment: CentOS5.5 x84, MySQL5.5.152. Two machines: master1: 192.168.5.143master2: 192.168.0.1493. Compile and install MySQL separately and test the connection.4. Create a user on both machines and grant the copy permission: master1: Mysql>

Oracle backup: Backup is redundancy. In essence, it refers to copying a few copies of the current data to other places, so that when the original data file is damaged due to various reasons, we can use the backup file to restore the status of the

Diagnose and resolve ORA-04031 errors When we try to allocate large blocks of continuous memory in the Shared Pool, Oracle first clears all the objects currently not used in the pool to merge idle memory blocks. A ORA-04031 error occurs if the

Differences between recover and restore in Oracle rman: Restore just copy the physical file, recover will consistent the database. Restore is a file-level restoration. Physical file restoration.A recover is a data-level recovery. Logical recovery,

I have never started linux before. This time, the customer's system installed linux, project release environment and database have been installed. As we were in a hurry to go online, we had to explore and handle it. Write it down for future

Expdp export simple notes 1. To create an accessible Oracle directory, you must grant the oracle: oinstall permission.[Root @ oracle/] # chown-R oracle: oinstall/data1 2. Switch to an oracle user[Root @ oracle/] # su-oracle 3. Create an expdp

There was a long question: Why should Oracle create two dirty lists: one Checkpoint Queue and the other Lruw? Now you can give a periodic answer: The purpose of the two linked lists is different. The Checkpoint Queue is sorted by the time the data

Time-based recovery Time-based recovery restores the database to a time point between the backup point and the failure point. Time-based recovery can be used not only when the media fails, but also when the database runs normally. For example, if a

In a query statement using a view or nested view, Oracle merges these views to obtain the optimal execution plan and connects the tables in the view to the tables in the external query. -- Example: SQL>SelectE. first_name, e. last_name, dept_locs_

Deferred_segment_creation causes EXP-00003New features in version 11G. To avoid wasting resources, creating a non-partitioned empty table will delay the creation of segment, including the table-related objects LOBS and indexes.Explanation of

Oracle spatial function exampleDisplay the area of the computing Oracle spatial Space ObjectSelect mdsys. sdo_geom.sdo_area (shape, 0.005) from jbnt_xzq; // Calculate the area of the geometric object based on the coordinates of the Surface object/200

Question: known company employee table EMP (EID, ENAME, BDATE, SEX, CITY ), Department table DEPT (DID, DNAME, DCITY ), Worksheet WORK (EID, DID, STARTDATE, SALARY ). The fields are described as follows: EID-employee ID, which can contain a maximum

RMAN list Command1. list the corresponding event RMAN> list incarnation; 2. List backups2.1 Overview of available backup RMAN> list backup summary;B Indicates backupF indicates FULLA Indicates archive log0 1 indicates incremental backupS indicates

Oracle 10 Gb or above password failureOracle em cannot log on. My own problems are summarized as follows: Two of them may have invalid passwords.1. sysman2. dbsnmpSYSMAN and DBSNMP are different from Oracle's EM.DBSNMP is a user used in the Oracle

Software: Aix 6.1 Oracle 11g Installation Process 1. Aix Installation Put it into the CD, start the system, hear a beep, speed at 5, then select the language, enter the menu, select a new installation. Wait ...... 2. Install ssh Remote