Oracle

-Basic connection operations Sqlplus scmgt/scmgt as sysdba connect to the Oracle database // scmgt Sqlplus "scmgt/scmgt @ testdb" connects to another databaseSelect name from V $ database; view the current database nameSelect table_name from all_

36. add_monthsAdd or subtract a monthSQL> select to_char (add_months (to_date ('000000', 'yyymmm'), 2), 'yyymmm') from dual; To_cha------200002SQL> select to_char (add_months (to_date ('000000', 'yyymmm'),-2), 'yyymmm') from dual; To_cha------199

Kettle was used due to the Informatica bug. I used it for the first time today. I found it to know the master of kettle.ProgramStartup method: run data-integration \ spoon. bat. After the startup, it is found that the database cannot be

Oracle architecture, I think, can be divided into: memory structure, process structure and storage structure. The process structure serves as a bridge between the memory structure and the storage structure. The implementation of Oracle architecture

After 10g R2, Oracle provides a new parameter commit_write to control the write behavior of Oracle logs after the client commit. This parameter value has four combinations. · Immediate, waitNote: When server process is submitted, semctl is used to

(I) First query the CPU and IO usage at the system level: Top, iostat, Sar...(Ii) exec dbms_workload_repository.create_snapshot ();(Iii) RMAN target/debug trace =/tmp/rmandebug.txt log =/tmp/rman_log20130727.txtExecute backup(Iv) exec

Recently, the company power failure, found that Oracle Data under Linux and the listener after the normal start, the client PLSQL still cannot connect to the server, reported ORA-12514 error, It is found that the Oracle server listens to the

** We recommend that you use DBMS_Scheduler (note) /* Query: Select job, broken, what, interval, T. * From user_jobs t; the unique identifier of the job, whether the automatically generated broken is running, N; run; Y: stop what is the name of the

Why can Oracle varchar2 (4000) connect with the JDBC thin driver only store 666 Chinese characters? Who says they can only store 666 Chinese characters? Varchar2 is a maximum of 4000 bytes, So it depends on your Oracle character set. If the

Oracle role 1. What is a role?In the previous sections, I described permissions and users. Slowly, you will find a problem: if a group of people have the same permissions they need, it will be inconvenient to manage their permissions. Because you

The difference between the Oracle database and the MySQL database is what we will introduce in this article, hoping to help you. 1. Group function usage rules In MySQL, group functions can be used at will in select statements. However, if a group

Sometimes, when we perform database connection tests or deploy the system, we may encounter problems with data. Let's share one of my experiences over the past two days. The scenario is as follows: the project needs to be transferred to other

Two features of a role 1) role DelayDelayed How to enable the role to take effect immediately:Set role name;For example:Set role resource;Delay recoveryThe following experiment demonstrates the delay recovery:Session (1) SCOTT:Sys @ orcl> conn Scott/

X $ table is the core part of the database. These tables are used to track internal database information and maintain normal operation of the database. The x $ table is encrypted and is not described in the Oracle documentation. Oracle uses these x $

(I) three major functions ① Collect and delete index, table, and cluster statistics ② Verify the structure of tables, indexes, and clusters ③ Identification table and cluster and row migration and row Link For analyze's function of collecting and

Indexes, like tables, also belong to segments. It stores user data and occupies disk space like a table. However, the data storage form in the index is very different from that in the table. When you understand the index, you can imagine a book in

First, express my position, I absolutely support foreign keys and must add indexes! Although this requirement has been lowered in the higher version of Oracle, the following causes are still involved: ① Deadlock The primary cause of the deadlock

I still want to worry about it. If you want to learn the Oracle architecture thoroughly, you must learn it based on the backup and recovery experiments and principles. I will also write a blog later. Here I am introducing the memory structure, just

The conversion of rows and columns is often required when writing SQL statements. It may be difficult for a newbie to use the decode and sum functions, this problem can be solved. Create Table Test (name char (10), KM char (10), CJ number) Insert

Latch is a mutex mechanism used to protect the shared memory structure in the memory (system global zone, SGA. Latch is like a memory lock, which can be activated and released quickly by a process to prevent concurrent access to a shared memory