Database Administrator

1,If the date to be inserted is the current time, the simplest method is to use the date function sysdate that comes with Oracle.When creating a table, declare the default value of the field as sysdate, as follows:Create table examples(Names varchar

The difference between OracleLob and OracleBFile is that the data of the former is stored on the server rather than in the physical files of the operating system. It can also be a read/write object, which is different from OracleBFile (the latter is

I always thought that MySQL would randomly query several pieces of data. SELECT * FROM'Table'ORDER BY RAND() LIMIT5 You can.However, the test results show that the efficiency is very low. It takes more than 8 seconds to query 5 data records in a

Lab environment:Red Hat Enterprise Linux Server release 5ORALCE 10g 10.2.0.1 I. Disk planning and partitioningMy lab machine has three hard disks, sda, sdb, and sdc. Sda is only used to install the operating system and application software. sdb is

I. Resource requirements:At least 1024 MB physical memory1024-2048 requires 1.5 times of interactive space2048-8192 requires 1 time of interaction space8192-requires 0.75 times of interaction spaceAt least 400 MB/tmp temporary directory SpaceOracle

1. query and modify the undo_retention parameter: Run the show parameter undo command to view the current database parameter undo_retention settings. Shown as follows: Undo_management string AUTOUndo_retention integer 10800Undo_suppress_errors

I. Path:/EASData/EASBAK/autobak Ii. Script Name: eas_expdp.sh Iii. Script content: #! /Bin/sh#===================================================== ==================# SCRIPT: eas_expdp_MontoSat.sh# AUTHOR: Jackey# Date: 2010-09-29# Rev. 1.0#

[Problem description]1. garbled characters are displayed for file names containing Chinese Characters in Linux;2. Use the vi editor to view Chinese characters with garbled characters;3. sqlplus enters the database to view Chinese characters with

After MySQL is compiled and installed, it cannot be started properly. Example: Prompt 'can't connect to local MySQL server through socket '/tmp/MySQL. sock' I have read that this file does not exist, but if MySQL is started properly, it should be

The syntax of the SELECT... for update statement is as follows:SELECT... for update [OF column_list] [WAIT n | NOWAIT] [skip locked];Where:The OF clause is used to specify the columns to be updated, that is, to lock specific columns on the row.The

1. Create Or Replace FunctionPostgresql (p_tnameVarchar2, P_colnameVarchar2)ReturnClobIsV_tmpVarchar2(200);V_result clob;V_cum sys_refcursor;BeginOpenV_cumFor 'Select' |P_colname| 'From' |P_tname;LoopFetchV_cumIntoV_tmp;Exit

First, you need to repeat the related concepts. Functions in Oracle databases can only be called by others. stored procedures can be executed separately and stored procedures can be called, the role package can place any statement (process, function,

Recently developed a J2EE project, using the database is Oracle, the test process found that occasionally there is a ORA-01461 can bind a LONG value only for insert into a LONG column exception thrown, at first, an exception was thrown because the

Execute the following method immediately, and pass the current variable in with USING. EXECUTE IMMEDIATE'Begin'Work_Order_Req_Line_Util_API.Create_Po_Allowed (: requisition _,: line_no _,: release_no _);END ;'USING requisition_no _, line_no _,

Due to work needs, the storage process has been being written recently. After three years of work, I have been doing management, and I have never been familiar with the stored procedure. This time, I can practice it well. Here is an important reason

Due to development needs, MySQL 5.5.9 needs to be installed and installed now. There are always errors when rpm is used, and there are still a lot of troubles related to the issue. In addition, no Binary Package is found, I had to find the source

Use the postgres 9.0.3 installation package of the x86_64 binary version downloaded at postgresql.org to decompress it to/opt/pgsql. After using the initdb command to initialize the database, log on to the database using the psql command as usual,

There are usually two ways to use DB2 logs: cyclic logs, that is, do not use the archive log mode. The other is the archive log mode, which is the cyclic log mode by default, that is, logs cannot be archived or backed up online. The following table

No time to check the same configuration of the Oracle database on a daily basis. Later, it was discovered that the master database did not synchronize archiving logs to the slave database because the slave database was not enabled after power

Configure Oracle lsnrctl and auto start 1. Set Host Name [Root @ www ~] # Cat/etc/sysconfig/networkNETWORKING = yesHOSTNAME = www.bkjia.com 2. Set the Host Name and IP address [Root @ www ~] # Cat/etc/hosts127.0.0.1 localhost. localdomain localhost4