Database Administrator

Oracle recursive functions Oracle start with connect by usage Connect by prior recursive algorithm in oracle In Oracle, the start with... connect by prior clause connect by is used in structured queries. Its basic syntax is:Select... from tablename

Build and manage Oracle 11g Active Data Guard Note: You can refer to the notes and ideas of many people on the Internet, and sort out notes after your own hands-on experience for your reference only. Data Guard differs from RAC in that in general,

How to Create a tablespace in Oracle Create a tablespace in Oracle CREATE [UNDO] TABLESPACE tablespace_name[DATAFILE datefile_spec1 [, datefile_spec2] ......[{Mininum extent integer [k | m]| BLOCKSIZE integer [k]| Logging clause | FORCE LOGGING|

RMAN backs up the database and restores it to another machine. 1. dbid and data file name query on the source database run in archive ModeSelect dbid from v $ database;Select file #, name from v $ datafile;Create pfile from spfileSelect * from v $

Greenplum synchronization to Oracle script Developed a solution to synchronize data from Greenplum to Oracle, and wrote a script for regular scheduling. Installing Oracle 12C in Linux-6-64 Install Oracle 11gR2 (x64) in CentOS 6.4) Steps for

Detailed description of Oracle user Creation 1. User conceptsThe user, that is, the user, is generally the "person" who accesses the Oracle database ". In Oracle, users can control various security parameters to maintain database security. These

Install SQL Developer on RHEL5 The process of installing SQL Developer is relatively simple. You should first install java support and then install the SQL Developer software. The order can also be reversed. Then configure the Java point of SQL

Troubleshooting of abnormal shutdown of MySQL Slave The production environment has a Master-Slave replication of MySQL. A while ago, the network of the data center was upgraded, but after a general network fault is recovered, you only need to start

Detailed Oracle 11G restart uard restart process Scenario: restart the database, do not restart the linux system, so you do not need to consider listening programs,# Linux input lsnrctl start1. Close the database1.1 shut down the master

Alter constaints, alterconstaints 1. Create a federated primary key Alter table name add constraints end name primary key (column name, column name ..); 2. New Characters Alter table name ADD (column datatype [default value] [NULL/not null]);

How to view and delete a unique index in mysql How to view and delete a unique index in mysql. View unique indexes: Show index from mytable; // mytable is the table name. The query result is as follows: After a unique index is

Dba_hist_ SQL _plan, dbahistsqlstat I would like to express my gratitude for the help of elders who have prepared this article. The applicable oracle database version is oracle 10 Gb or later.   This view is important because one column in this view

Database design, database design toolsDatabase Design ER Model Entity-Relationship, Entity-link model. The graphical representation of this model is an erdiagram. 1. Use a rectangle to represent an object. 2. Use an ellipse to represent object

Analysis of slow expdp backup and expdp backup -- Export Problem Analysis-- Two time Statement Analysis: This statement exports only 4,059,292 of the Data. After 10 minutes, the data does not continue to be exported.Snap Id Snap Time Sessions

Mysql merges values of the same column. mysql merges values of the same column. I have the following query conditions: I want the final display Effect Merge group_name with the same id into one row. Implementation Method: add the keyword

MySQL search: WHERE multi-condition, mysqlwhere WHERE can be searched by multiple conditions. The products table is as follows: After a WHERE, search by and based on two conditions and three conditions: B uses or to search for multiple

Mysql insert statement optimization, mysqlinsert statement1) if you INSERT many rows from the same customer at the same time, use the INSERT Statement of multiple value tables. This is faster than using separate INSERT statements (several times in

Explain oracle sequence, oraclesequence 1. About Sequences (About Sequences) A sequence is a type of database object. Multiple users can generate consecutive numbers in sequence to automatically and uniquely increase primary key fields. A sequence

Chapter 1 (4 and 5) of Solr In Action 1.1 feature Overview Finally, let's take a quick look at the main functions of Solr based on the following categories: · User Experience · Data Modeling · New Features of Solr 4 This book provides a good search

Mysql merge table introduction, mysqlmerge table In Mysql databases, Mysql Merge tables are somewhat similar to views. Next let's take a look at the advantages of Mysql Merge tables and hope to help you. Advantages of Mysql Merge table:A: Separate