Solve the problem that Oracle occupies too much disk

background After the database has been running for some time, the table space has been increasing, but the actual amount of data is not so large. Deleting data or truncate tables does not reduce the tablespace. This is because when the table space is insufficient, it will expand automatically, but it will not shrink automatically. terms of se ...

Posted by lorewap3 on Wed, 18 May 2022 03:56:25 +0300

Installation of Oracle Database 11g Enterprise on CentOS (the most detailed and simple tutorial in the whole network)

Installation of Oracle Database 11g Enterprise on CentOS environment VMware Workstation 15 Pro CentOS 7 64 bit (CentOS-7-x86_64-DVD-1810.iso) If the environment is not ready, you can refer to: Installing CentOS for VMware virtual machines tool SecureCRT 8.7 SecureFX 8.7 Navicat Premium 12 PL/SQL Installation package Oracle Databa ...

Posted by sy-co on Tue, 10 May 2022 21:06:46 +0300

SQL language multi table query (oracle)

multi-table query When the queried data does not come from one table, you need to use multi table join to complete the query. Query the associated data according to the relationship between the data in different tables. 1, Cartesian product In mathematics, the Cartesian product of two sets X and y, also known as the direct product, repr ...

Posted by grafnic1732 on Sun, 08 May 2022 20:34:12 +0300

Technology sharing | common causes of MySQL startup failure

Author: Yao yuan Focus on Oracle and MySQL databases for many years, Oracle 10G and 12C OCM, MySQL 5.6, 5.7, 8.0 OCP. Now Dingjia technology serves as a technical consultant to provide database training and technical support services for colleagues and customers. Source of this article: original contribution * produced by aikesheng o ...

Posted by squalls_dreams on Sun, 08 May 2022 03:53:20 +0300

Install Oracle11g silently Under Oracle Enterprise Linux

1. System requirements 2. Check environment 2.1. Check physical memory: [root@kindo-dev-03 ~]# grep MemTotal /proc/meminfo MemTotal: 16267584 kB 2.2. Check the exchange space: [root@kindo-dev-03 ~]# grep SwapTotal /proc/meminfo SwapTotal: 8257532 kB 2.3. Inspection / tmp Directory: [root@kindo-dev-03 ~]# df -k /tmp file syste ...

Posted by RyanW on Fri, 29 Apr 2022 05:01:06 +0300

Full record of installing Oracle11g in CentOS7 in 2021

Installing oracle on linux is often used in actual operation and maintenance. Just recently, I reinstalled the system. By the way, I recorded the whole process of installing oracle. environmental information Different environments may have small differences, which are similar. To prevent influence, the version information I use is give ...

Posted by ibo on Tue, 26 Apr 2022 01:17:39 +0300

Solving the problem of slow query speed of Oracle data volume above 10 million

Solving the problem of slow query speed of Oracle data volume above 10 million 1. Change the original table to a partitioned table 1.1 partition table judgment 1.2 reconstruction zoning table 1.2.1 rename the original watch 1.2.2 reconstruction of zoning table 1.2.3 copying data 2. Create index 2.1 launch execution plan 2.2 no ...

Posted by Mundo on Fri, 22 Apr 2022 04:12:11 +0300

Oracle merge data operation (MERGE)

SQL standard added a new data operation statement in 2003: MERGE, which can complete the operation of INSERT statement, UPDATE statement and even DELETE statement at the same time. Standard merge statement Its basic syntax is as follows: MERGE INTO target [AS t_alias] USING source_table [AS s_alias] ON (conditions) WHEN MATCHED THEN UPD ...

Posted by lobo235 on Tue, 19 Apr 2022 07:06:17 +0300

Three tier architecture of software & principles to be followed

Three tier architecture Layered mode Layered mode is the most common architecture mode The layered pattern is the foundation of many architectural patterns layered Separate the components of the solution into different layers Maintain cohesion between components in the same layer Loose coupling between layers Why do I need a layer ...

Posted by davo666 on Tue, 12 Apr 2022 08:42:59 +0300

Creation of partition table of ORACLE

What is a partition table? Why use partition table? How to create a partition table? If the data in a table in your database meets the following conditions, you should consider creating a partitioned table. 1. There are a lot of data in a table in the database. What are many concepts? Ten thousand? 20000? One hundred thousand or one million? T ...

Posted by Garrett on Mon, 11 Apr 2022 09:20:24 +0300