Oracle

　　　　1. Wait for the monitoring case:Select Event,sum (Decode (wait_time,0,0,1)) prev, sum (decode (wait_time,0,1,0)) curr,count (*)From v$session_waitGroup BY event order by 4;　　　　2. Race conditions for rollback segments :Select

After restoring a database on the Oracle test server, a TNS-12541, tns-12560,tns-00511 error occurred when starting the listening service, as shown in the following scenario:[Email protected] admin]$ lsnrctl statusLsnrctl for linux:version 10.2.0.4.0

Oracle storage components for cluster partsOracle A cluster component consists of its storage structure and a set of processes running on each cluster node. The storage structure consists of two parts: OCR, voting disk plus two local files-OLR and

1. Introduction to the development environmentSpring Data 1.6, JDK 1.6, Oracle 11g, Hibernate 4.3.52. The question was raisedIn development, you use annotation to configure the entity, which is the mapping of the object to the table, and the code

Flashback: Fix logic error, back from current point1. Flash back has a dedicated flashback log, stored in the FIA, but only the flashback database will be used2. If you do a full database flashback, the equivalent of an incomplete recoveryFlash back

Database health status checkUse utl directives, Statspack, awr to check the health of the databasePremise: > Show parameter time_ timed_statistics;NAME TYPE VALUE-------------------------------------------------

1. Client-side encodingView method: Open the registry of the server where the database resides (enter regedit in the Run window) Hkey_local_machine->software->oracle->home0->nls_lang, Check out what the database client code is.2. Server-side

To completely uninstall the oracle11g step:1. Start-> Settings-> Control Panel-> Management Tool-> Service stop all Oracle services.2, Start-> Program->oracle-orahome81->oracle installation products-> Universal Installer, click "Uninstall

The Oracle 11g is usedIn fact, it has been a few, but not much study, now began to re-learn, including SQL statements and so on.Start after installation,I installed the client sqldeveloper, but I need to connect after entering, I forgot how to do it,

--1. Learning job in Plsql--Learning Job--Build Tables CREATE TABLE Test_job (para_date date); Commit INSERT into test_job values (sysdate); Commit Select* fromTest_job; --Create a storage process create or replace procedure Test_jobproce

Indexes in OracleIn a relational database, an index is a database structure that is related to a table and is another important schema object other than a table. An index is a helper object that is built on one or more columns of a table to increase

The structure of the Oracle IF statement is similar to most languagesIF condition then expr; elsif condition then expr; ELSE expr; END IF;As an example:Select count (Distinct index_name)  INTO CNT FROM USER_INDEXES WHERE  Table_name=c1. table_name;  

The LAG () and lead () statistics functions are able to fetch the first n rows of the same field and the values of the last n rows in a single query . Such operations can be implemented using table joins to the same table, but using lags and leads

Big New Year's also want to knock code, think is intoxicating. Busy today to get out of the set, when the function test found that the value of the ID has been 0, a look at the value of the ID is not self-increment, has been the default of 0. So

Refer to the official documentation (download along with the database file)Oracle®databaseQuick Installation Guide10gRelease 2 (10.2) for Linux x86-64The official documentation describes the installation using a graphical user interface. However,

It seems that some people still do not understand the true meaning of the schema, and now I have to tidy up a bit, I hope to be helpful to everyone.Let's start by looking at their definition:ASchemais a collection of the database objects (used by a

First, Create database linkCreate Public Database Link to_xxx Connect to userobj using' (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = XX). Xx. Xx. XX) (port= 1526)) (Connect_data = (SERVER = dedicated) (service_name =xx)) ';Description

Vernacular Oracle: Hotspot table optimization Summary1. Optimize the SQL related to the hotspot table. If the SQL Execution takes too long, it will hold latch for a long time. For statements with a small number of returned results, check whether

ORA-00604: error occurred at recursive SQL level 1, ora-00604recursive When you use an account ESCMOWNER in the test environment to ALTER the database, the following error is always reported: ORA-00604: error occurred at recursive SQL level 1 ORA-20

Some advanced management case studies of ORACLE11GDataGuardAfter setting up ORACLE 11G dataguard, I also conducted a Role Switching experiment. switchover has failover, and I feel a lot of benefits. Then I continue to study some of the advanced