Oracle

Oracle's Lock table and unlockSELECT/*+ Rule */s.username,Decode (L.type, ' TM ', ' TABLE LOCK ',' TX ', ' ROW LOCK ',NULL) Lock_level,O.owner,o.object_name,o.object_type,S.sid,s.serial#,s.terminal,s.machine,s.program,s.osuserFrom V$session s,v$lock

Oracle a database exception was caused by insufficient disk space. The size of the data file needs to be reduced to resolve. 1 , check the name and number of the data fileSelect File#,name from V$datafile;2 , see which data file occupies the largest

One, Oracle 11gThe automatic collection of statistics data is available in the 11g version of Oracle. One of the steps in deploying 11g Oracle software during deployment is to prompt for the ability to start this feature (which is enabled by default)

Server hardware requirements: Memory >1GB, if it is a virtual machine, you must set the memory to 1.5G or more. Determine the hostname, after the installation is complete, do not modify the host name, once the modification will lead to the

--Check the salary rankings of all teachers--rank (): Same row with equal values, followed by rank jumpsSelect Tname,sal,Rank () Over (order by Sal) as salary rankFrom teacher--dense_rank (): The same row with equal values, followed by successive

--Basic functions--select Name,count (ID) from Work_test GROUP by name have count (ID) >1--select Upper (name), T.*,lower (name), substr (name,1,5) from Work_test t--Even table update/*update Work_test Set (Price) = (select T.price from Work_test t

How to connect Oracle databases in C #I. About the operation of the database1. Database connectionThere are 2 kinds:The first: The old method (more rigid, not conducive to flexible operation), that is, with the OracleConnection class to

One, parameter-free stored procedure--Create a stored procedureCreate or Replace procedure getdate as datetime varchar2 (+); begin Select to_char (sysdate,'yyyy-mm-dd hh24:mi:ss' from dual; Dbms_output.put_line (' current time:'| | datetime);

When you define variables, constants, and parameters in your program, you must specify the PL/SQL data type for them. When you write a PL/SQL program, you can use four types, such as scalar (scalar) types, composite (Composite) types, reference

What is the sequence "Sequence"(1) Similar to the Auto_increment automatic growth mechanism in MySQL, but no auto_increment mechanism in Oracle(2) is a mechanism provided by Oracle to produce a unique numeric value(3) The main health value of the

PS aux | grep Ora_pmon has several database servers that have several this process (process monitoring process and external dealings)Vim Sqlnet.ora This can make the database slightly secure, so that sqlplus can not

Today, I have encountered the problem of 11GR2 connection, before, because the application there is no in-depth inspection, did not find specific reasons, think of this version of the Oracle bug it.The last approach is to use the shell script to

1, download Oracle's compressed files on the official website, and download all two of them. and two simultaneous check unzip in a folder inside.　　2, after decompression, such as, click Setup.exe Wait a moment, 3, start the installation:Do not

Oracle should be familiar with how to view and set the maximum number of connections for an Oracle database. Let's go over it again. To view the current number of connections, you can use SELECT COUNT (*) from v$process;Maximum number of

I. What is the Oracle character setThe Oracle character set is a collection of symbols that interpret a byte of data, have a size, and have a mutual containment relationship. ORACLE's support for national language architectures allows you to store,

(1) View character set (three are equivalent)Copy CodeThe code is as follows:SELECT * from v$nls_parameters where parameter= ' Nls_characterset 'SELECT * from nls_database_parameters where parameter= ' Nls_characterset 'SELECT * from props$ where

--View All tables under this user in the ORACLE databaseSELECT table_name from User_tables;--View All tables under All users in the ORACLE databaseSelect User,table_name from All_tables;--View all columns under this user in the ORACLE databaseSelect

  Data type Parameters Describe CHAR (n) N=1 to 2000 bytes Fixed length string,n bytes long, if not specified length, default is 1 bytes long (one kanji is 2 bytes) archar2 (n)

Storage functions1. Introduction to Stored ProceduresLet's take a brief look at the syntax of Oracle's stored procedures, as follows:　　　　Simple syntax for stored proceduresHere's a brief look at the advantages of using stored procedures:(1) easy to

Install the database, generally first installed grid infrastructure, after the database, the network must first out of the pre-installed grid infrastructure on port 1521.Each time the template is built, a avatar is created, and the avatar is