Database Administrator

Data Pump is a new function launched by Oracle 10g. The difference between expdp/impdp AND exp/imp is that exp/imp is a client tool and can be used either on the client or on the server. Expdp/impdp is a server tool and can only be used on the

1. OPatch tool description The opatch tool was mentioned in the previous Oracle patch system blog: Introduction to Oracle patch system and opatch tools Since version 9.2, Oracle has implemented the opatch patch installation tool. opatch uses a

Table:Select * from cat;Select * from tab;Select table_name from user_tables;View:Select text from user_views where view_name = upper ('& view_name ');Index:Select index_name, table_owner, table_name, tablespace_name, status from user_indexes order

Connect to the Hibernate configuration file of the Oracle databaseThe Hibernate configuration file connected to Oracle has two formats: xml and Java attribute file. The codes of the configuration files in these two formats are given below.1.

Add a new column to a table with records and specify not null to report a ORA-01758. What should I do? 1. Specify the default value for the newly added column. 2. Clear the records in the table and add new columns. The experiment is as follows:

Some time ago, because of a project, MYSql Data Synchronization Service was required. However, because the website space service provider does not provide remote connection to MYSql, therefore, the NaviCat client cannot be used to connect to the

Next, we will explain the Sqlalchemy framework. Here is another example. Related reading: database framework of Python 3.x Sqlalchemy for SQlite operations As follows: This example is based on others' Code. _ Author _ ='Minggxu9' ImportSqlalchemy

Oracle function INSTR usage: (Source string, target string, start position, matching serial number) In Oracle/PLSQL, The instr function returns the position of the string to be truncated in the source string. Only retrieval once, that is, starting

First install CentOS6.0 ============== Not to mention. Install it. The only thing to note is that the Checking the Software Requirements section in the Oracle 11G Installation guide will require the Installation of some Software. These software are

1. Create a temporary tablespace Create temporary tablespace TS_TMP TEMPFILE 'd: \ Oracle \ ORADATA \ TMP. dbf' SIZE 32 M AUTOEXTEND ON NEXT 32 m maxsize 2048 M Extent management local;   2. Create a data table space Create tablespace

Use Crontab in RedHat Linux to implement Oracle 10 Gb scheduled backup (including SFTP download instructions ). This is to say that regular backup is a hot backup, that is, writing a shell script. The syntax is oracle10g, and 9i is slightly modified

In an application environment, all servers use and manage the same database to distribute the workload of each server. The hardware requires at least two servers, A shared storage device is also required. At the same time, two types of software are

Oracle Database Upgrade has always been a complex project. DBAs need to spend a lot of time and effort on preparation for Product Database Upgrade because of its high complexity, therefore, even if you are fully prepared, unexpected problems may

In the following example, two shared services, one Configuration Service and one mongos service are enabled. All these services are tested on the same server. Of course, they can also be deployed on different servers.1. Create a Shards

Instance:Create a USERINFO database table: Of course you can write it like this:Drop table USERINFOCreate table USERINFO(EnglishName varchar (30 ),ChineseName varchar (30 ),Sex varchar (10 ),Age int,BirthPlace varchar (100 ),BirthDate date default

The database administrator can access any table space (online) or offline (inaccessible) except the SYSTEM tablespace (tablespace) when the database is in the open state ). The SYSTEM tablespace is always online when the database is in the open

Database users should not be locked 1) view the default number of database locks[SQL] SQL>SetLinesize 2000 SQL>Select*FromDba_profilesWhereResource_nameLike 'Failed _ LOGIN_ATTEMPTS %'; PROFILE RESOURCE_NAME RESOURCE LIMIT --------------------

In a large text (more than 1.5 GB), when there are both carriage return line breaks and carriage return end characters, if the size of the line feed end is greater than sqlldr's default buffer of 1048576, an error is reported. SQL * Loader-510: the

The slave server reports an error due to the abnormal restart of the master server. The error is as follows:Show slave status error: mysql> show slave status\GMaster_Log_File: mysql-bin.000288Read_Master_Log_Pos: 627806304Relay_Log_File: mysql-relay-

The MySql and Oracle Database plug-in drivers are compiled on Mac, but unfortunately they cannot be loaded in the program or connect to the database. Set QT_DEBUG_PLUGINS = 1 in the environment variable. After the program is started, Qt will report