Oracle

Sqlplus automatically runs two scripts at startup: Glogin.sql, login.sql these two files The order of execution is 1. Default to find Glogin.sql file execution under $oracle_home/sqlplus/admin path 2. Default in the current path to find Login.sql

Order by unstable sortAsk a question: is Oracle a stable sort algorithm when ordering by? found that after sorting with a type, do a paging query, the first page of data and the second page of the data is repeated suspected to be order by, two

SQL Server gets the first record in each group In daily life, we often need to record some operations, similar to the operation of the log, the last record is valid data, and maybe they belong to different aspects, functions below, from the

I. Summary Oracle hard parsing and soft parsing are problems that we often encounter, so we need to consider when to produce soft parsing when a hard resolution is generated and how to judge SQL Execution Process When a SQL or Pl/sql command is

The Oracle tutorial that is being looked at is: An Introduction to Oracle based object-oriented Technology Brief analysis of the Developer Network Oracle. I. OverviewAn object is a new feature in the above version of Oracle8i, which is actually an

A code snippet to help explain. The code snippet is as follows: Copy Code code as follows: Declare Type T_indexby is table of number Index by Binary_integer; Type T_nesteed is table of number; Type T_varray is Varray (a) of

The parallel operation characteristic of Oracle database is to forcibly extract the free resources of database server (mainly CPU resources), and to divide and treat some high load data. Parallel operation is a non-deterministic optimization

I. Ordinary table (Heap table): For most design scenarios, there are advantages and disadvantages. Advantages:1. Simple and convenient grammar2. Suitable for most scenes Disadvantages:1. Update log cost is large2.Delete Unable to free space (HWM

Oracle stored procedure basic syntax stored procedures1 CREATE OR REPLACE PROCEDURE Stored procedure name2 is3 BEGIN4 NULL;5 end;Line 1:The Create OR REPLACE PROCEDURE is an SQL statement that notifies the Oracle database to create a stored

1. Oracle 11g R2 Installation Manual (graphics tutorial) for Windows Before installation, you need to confirm the following points: Your memory is not a problem (this is important, if your machine often blue screen then don't pretend, or you cry)

There are three different ways to throw an exception 1. Run-time engine via Pl/sql 2. Using the Raise statement 3. Call Raise_application_error Stored Procedure When a database or Pl/sql error occurs at run time, an exception is thrown

--The first method: Query Dba_tab_columns Copy Code code as follows: Select Column_name,data_type,data_length From Dba_tab_columns where table_name =upper (' table name ') ORDER BY column_name --This method requires DBA

The Oracle Wm_concat (column) function is what we often use, and here's how you can use the Oracle Wm_concat (column) function to implement a field merge if you have an Oracle Wm_concat (column) If you are interested in using a function, look at it.

In a project, you can use 2 kinds of data, such as Oracle, Ms_sqlserver also use, ms-sql data generic class in many tutorials have ready-made examples and code, but Oracle is relatively rare, but this project is just used, posted and shared with

In an Oracle database, Rman backs up a lot of scripts, and here's a case of how a shell script can be backed up by Rman, and FTP uploads the Rman backup file and the archive log file script. fullback.sh inside call rman command do database backup,

First to create a AA user: sys@orcl> create user AA identified by AA; User created. To view user rights with an HR user login: Sys@orcl> Conn Hr/hr Connected. Hr@orcl> select * from Session_privs; Privilege -----------------------------------

Data files are deleted directly from the operating system when the database is open Because in a Linux system, a process that has previously opened the file still holds the appropriate file handle, and the file that you point to is still readable

This article lists 3 ways to delete duplicate records, namely ROWID, group by and distinct, which can be consulted by small partners.For example, there is now a person table (table name: peosons)If you want to name, ID, address, the three fields

With Oracle 11g 64-bit servers, install 64-bit, 32-bit clients, Sqlplus cannot connect to the database, Plsql can connect problems.A lot of online search, can not solve the problem, provide one of the following.Environment variablesRight-click

Backup solutionUse the following methods to perform backups: Recovery Manager Oracle Secure Backup User-managed backupsRecovery Manager (RMAN)is recommended for useOracle DBbackup method.Oracle Secure Backupcomplements existing functionality by