Oracle

The introduction of Oracle temporary tables is a good strategy for multi-table cascading queries or complex transactions with large data volumes. As a result, you often encounter situations where you need to work with stored procedures and temporary

CREATE TABLE Testemp (ID varchar2 () default Sys_guid (),Deptno VARCHAR2 (,--Department code)ename varchar2 (,--name)Sal Number (10)--payroll)----Table Name DescriptionComment on table testemp is ' test dedicated table ';----Field NotesComment on

Create, modify, and delete an Oracle database sequence. 1. Create a sequence 1.1 create a sequence: create sequence seqtest; 1.2 query the current Sequence Value: select seqtest. currval from dual; 1.3 next value of the query sequence: select

Usage and instance resolution of merge into in oracle, oraclemerge Merge into format: MERGE INTO [target-table] A USING [source-table sql] B ON([conditional expression] and [...]...) WHEN MATCHED THEN [UPDATE sql] WHEN NOT MATCHED THEN [INSERT

Oracle Database Transaction Features and usage instructions, oracle Database Oracle Database transactions 1. What is a transaction? A transaction in a database is a logical unit of work. A transaction is composed of one or more SQL statements

Solution to the Oracle database deadlock problem: oracle DatabaseQuery the locked table Select B. owner, B. object_name, a. session_id, a. locked_mode from v $ locked_object a, dba_objects B where B. object_id = a. object_id;Concatenate and unlock

Installation tutorial for oracle11g database, oracle11g Database Windows 10 Family Edition x64 8g memory cpu i7-8550U 1. Extract the two files downloaded from the Internet to a file, and open and run setup.exe; 2. After a moment, if the

Oracle uses v $ sqlarea and v $ SQL to query the most resource-consuming tutorials, oraclesqlarea How to query the most resource-consuming data in Oracle using v $ sqlarea and v $ SQL v$sqlarea,v$sql Query the most resource-consuming query from V $

Seven restrictions that can invalidate Oracle indexes: Seven The goal of Oracle indexes is to avoid full table scans and improve query efficiency, but sometimes it is counterproductive. For example, if a table contains millions of data records and

Introduction to using the wm_concat (column) function in Oracle, oraclewm_concat Merge Fields Use the oraclewm_concat (column) function to merge fields, for example: shopping into u_id goods num ____________________________________________ 1 Apple 2

Detailed description of the deduplication (deduplication) method of the listparts () query result of the Oracle column-to-row function, oraclelistagg Today, when using the listparts () function to connect the full names of all people in different

Oracle linux installation and oraclelinux Installation Vi/etc/sysconfig/network change the host name to orcale   Vi/etc/hosts modify ing IP + Host Name Configure YUM   InstallYum install binutils compat-libcap1 compat-libstdc ++-33 compat-libstdc ++-

What should I do if oracle misoperations flash back ?, Flashback of oracle operations When operating on the Oracle database today, when doing an Update data, I accidentally wrote less where, which is careless. Therefore, all employee IDs are

Oracle Database-related data dictionary for performance problem analysis, oracle-related data The nine most important dynamic performance views of oracle! V $ session + v $ session_wait V $ process V $ SQL V $ sqltext V $ bh (prefer x $ bh)

How to Use wrap to encrypt your source code in Oracle ?, Oraclewrap Oracle provides a simple source code protection method, WRAP, which can convert program code into a pile of characters that cannot be understood.Many built-in Oracle programs use

Summary of various problems encountered after installing oracle Basic commands: Logon command Sqlplus Sqlplus User Name Sqlplus user name/Password Sqlplus/nolog -- Account connection command Conn Conn User Name Conn username/password -- Exit the

Analysis on the Impact of the Where condition execution sequence and the Where clause condition sequence on the Performance of Oracle databases, and the oracle clause1. Oracle database Where condition execution sequence: Because SQL optimization is

Oracle TOPSQL and oracletopsql -Top 10 SQL statements SELECT *FROM ( SELECT b.username AS username , a.disk_reads / DECODE(a.executions, 0, 1, a.executions) AS rds_exec_ratio , a.sql_text AS STATEMENT FROM v$sqlarea a, dba_users

Oracle Database SQL statement trigger instance description, oracle instance description An example of the oracle Database SQL statement trigger /**----------------------- * Statement-level triggers */ -- Create emp copy emp1 Create table emp1 as

Les08 user security management) [2080312], les082080312Purpose: To create and manage a Database User Account-authenticate a user-allocate a default storage zone (tablespace) grant and revoke permissions to create and manage roles create and manage