Oracle

Question: Does Oracle differentiate rowid from rownum? If they have differences, what are their differences? A: Just as your address uniquely identifies your location, an oracle rowid uniquely identifies the physical address of a piece of

Basic Oracle Stored Procedure syntax 1. Basic StructureCreate or replace procedure(Parameter 1 in number,Parameter 2 in number) IsVariable 1 integer: = 0;Variable 2 date;Begin End stored procedure name 2. Select into statementSave the result

  I. First, run the TOP command to view the spid numbers with more resources.   II. Query SQL statements by PID 1. The first method is to query multiple PIDs. (1) query the current time-consuming session ID, user name, sqlid, etc.In ('123',

Oracle often fails to start automatically when it is started. In this case, you can use batch files to enable automatic startup of Oracle databases. Create a batch file, such as execute. bat. The content is as follows:Sqlplus/nolog @ start. SQL

When learning Oracle, many people think that dbwn writing is related to commit. This is incorrect. In fact, there is no relationship between dbwn writing and whether the transaction is commit. Now, it turns out that an uncommitted transaction may

DBAs maintain Oracle and common undo scripts. Some of the previous articles also involve a lot of things. Here is a simple summary. 1) How to query the size of rollback segments used by a transaction in a database session? sys@ORCL> select

Whether we use dbca for database creation or manual creation. After the database creation task is completed, three parameters are very important for future production and use. Generally, we need to open them.The first one is log_checkpoints_to_alert.

Given the longitude and latitude of 2 points, the distance between the points is calculated by using Java code and the Oracle stored procedure (in meters) Oracle stored procedure: Create or replace procedure sp_get_distance (CX in number, cy in

Logminer is a tool provided by Oracle from 8i for analyzing redo log information. It includes dbms_logmnr and dbms_logmnr_d packages. The D behind it is a dictionary. It can analyze both redo log files and archive log files after archiving. You need

We know that every RDBMS has its own characteristics in SQL. So today, let's take a look at what features Oracle has. Meaning. Feature 1:Oracle analysis functions and window functions:Syntax: Function_name (, ...)Over ( )For example:Sum (SAL) over

1,Among them, the most common is update T1 Set B = (select B from T2 where t1.a = t2.a );However, pay attention to the impact of null values,If you are afraid of the impact of null values, write itUpdate T1 set tname = (select sname from T2 where t1.

Summary of rownum usage in Oracle! (Excellent) for the rownum problem of Oracle, many materials are not supported>,> =, =, between... and, only the above symbols can be used (,> =, =, .. and will prompt SQL syntax errors, but often cannot find a

The previous article introduced how to explain the struct and array in Oracle, Explain plan Select * from table (dept_array (department_type ( 1, -- DNO number (10 ), 'Name', -- name varchar2 (50 ), 'Location' -- location varchar2 (50) ) T

Official documentation Important references: This is a good example.1: Oracle Startup File priority: 1: spfilesid. ora2: Default spfile --> spfile. ora3: initsid. ora4: Default pfile --> 2: How to specify how to start the spfile File Oracle only has

Important reference 1: Important reference 2: Important reference 3: Reference slides 11g Data Dictionary reference Importance: Because the data dictionary contains user information, we need to query the data dictionary when logging on, and have

35 Here are some explanations. 1: Undo segment Concept When the database is modified, you need to save the old data to a place and modify it. The segment used to save the old data is the Undo segment. Previously, old things can be overwritten,

Document directory 1: close ---> nomount status 2: nomount --> Mount status 3: monnt --> open Important references Oracle contains three basic files: 1: Data File)2: Control File) 3: Online redo log file) Concepts of Oracle Database files:

First, you must have a table!Create Table example (ID number (4) not null primary key,Name varchar (25 ),Phone varchar (10 ),Address varchar (50) ); Then, you need a custom SequenceCreate sequence emp_sequenceIncrement by 1 -- add severalStart with 1

Recently used to restore data from the Oracle DMP FileWithout such information, I have collected some information online. I believe that we can successfully restore the DMP file back using the command line method. Here I am using the Oracle10g

I wrote TMD tricks on the Internet. Idea: PLSQL depends on OCI. dll and some other files in the client, so it must be provided. Locate listener. ora through the Environment Variable tns_admin,Tnsnames. ora to establish a connection. Steps: 1.