1. Problem Overview When the ORACLE database stores data, there is sometimes a phenomenon that the data in a table contains both UTF8 characters and GBK characters, and there may also be garbled data. NLS_CHARACTERSET is the database character set, NLS_NCHAR_CHARACTERSET is the national character set, and NLS_LANG is an environment variable of the Oracle […]
Tag: acl
06.Oracle data backup and recovery RMAN
oracle basic system learning directory 01.CentOS7 silently install oracle11g 02.Oracle startup process 03. Start with simple sql 04.Oracle’s architecture 05.Oracle database objects 06.Oracle data backup and recovery 07.User and permission management 08.Oracle tables 09.Partitioning of Oracle tables 10.Oracle synonyms and sequences 11.Oracle’s view 12.Oracle index 13.Oracle connects to Java through JDBC 14.Transactions in Oracle 15.Oracle11g […]
Oracle database error ORA-600: [4194] processing after recovery
Error ORA-600: [4194] Processing after Oracle database recovery Fault phenomenon Solution Rebuild UNDO tablespace ORA-600 [4137] error Possible cleanup work Fault phenomenon Phenomena: After completing the recovery of the NBU tape library, the test library will hang up within a few minutes after it is opened. The alarm log error is as follows: Errors in […]
[De Ge talks about database series]-Oracle 19C PDB creation encyclopedia
hello! Hello everyone, I am [IT Bond], known as jeames007 in the world. I have more than 10 years of experience in DBA and big data work. A highly motivated [blogger in the field of big data]! Member of China DBA Alliance (ACDU), currently serving the industrial Internet Specialized in mainstream Oracle, MySQL, PG, Gaussian […]
oracle scheduler job scheduled task practice
Oracle scheduler JOB scheduled task Article directory Oracle scheduler JOB scheduled tasks scheduled tasks basic grammar Create job Check job running status JOB stop JOB startup and deletion timed expression Actual combat Create stored procedure Create JOB Step on the trap View database system time zone View session time zone Modify database time zone Modify […]
How to create Oracle 19c pluggable database PDB
Overview of multi-tenant container database architecture diagram Multi-tenant container database components: 1. There is only one CDB Root (CDB$ROOT), which contains the metadata and data dictionary information of the Root and all PDB databases. 2. There is only one Seed PDB (PDB$SEED). Its function is to create templates for other PDBs. It is a read-only […]
Java car automatic path finding and obstacle avoidance avg scheduling simulation
uml diagram Graph.java import java.util.ArrayList; import java.util.Collections; import java.util.List; /** * @author: * @description：TODO * @date: 2023/3/4 1:53 */ public class Graph {<!– –> public int v; // number of vertices public int e; // number of edges static public List<List<Path>> pathArrayList = new ArrayList<>(); static public List<Node> nodes = new ArrayList<>(); static public int […]
Oracle-execution plan
Several ways to generate execution plans 1. EXPLAIN FOR grammar: EXPLAIN PLAN FOR SQL statement SELECT * FROM TABLE(dbms_xplan.display()); advantage: No need to actually execute SQL shortcoming: No relevant statistical information is output, such as how many logical reads, physical reads, recursive calls, etc. are generated. Unable to tell how many rows were processed Unable […]
Actual measurement: Oracle 19C hot cloning application pitfall avoidance guide
1. Background As Oracle 11g enters the extended support stage, Oracle 19C, as the final stable version of the 12C family, has been well known and used in production by most companies. My company is also trying to deploy, test, upgrade, and migrate 19C, so I took this opportunity to test the hot cloning feature. […]
Oracle tablespace
1. Concept 1.1 The relationship between users, tables and table spaces Each project corresponds to a table space. Oracle database stores physical tables through table spaces. A database instance can have N table spaces, and one table space can have N tables. Then create a user corresponding to this table space Therefore, when doing large-scale […]