Will insert in Oracle lock the table?
Insert in oracle will lock the table; when Oracle executes DML statements such as insert, it will apply for a lock on the table being operated. When two insert statements attempt to operate on a table at the same time, a session will occur. It is blocked, waiting for other sessions to commit or rollback, thus causing a deadlock.
The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.
Will insert in oracle lock the table?
Will insert in oracle lock the table?
When ORACLE executes DML statements such as insert, it will automatically first Apply for a TM lock on the table to be operated. When the TM lock is obtained, it will automatically apply for a TX type lock. When two or more sessions execute DML language on the same record of the table, the first session locks the record, and the other sessions are in a waiting state until the TX lock is released after the first session commits, and the other sessions Only sessions can be locked.
Consideration is because two insert statements try to insert data with the same PK or unique value into a table at the same time, causing the session to be blocked, waiting for other sessions to commit or rollback, thus causing a deadlock.
In this case, as long as any one of the sessions is submitted, the other one will report ORA-00001: unique constraint is violated and the deadlock terminates; or one of the sessions is rolled back and the other one can execute normally. .
In Oracle, the reason for locking the table is that when a program performs an insert on a table and has not yet committed, another program also performs an insert on the same table, then a resource will occur at this time. Busy exception, that is, lock table.
The main reasons for locking tables are:
(1) Program A performs an insert on tableA, and before commit, program B also performs an insert on tableA. Then a resource busy exception will occur at this time, which is lock table
(2) Lock table often occurs in concurrency rather than parallel (in parallel, when one thread operates the database, the other thread cannot operate the database. cpu and i/o allocation principles)
Methods to reduce the probability of locking the table:
(1) Reduce the time between the execution of insert, update, and delete statements and commit. Specifically, change batch execution to single execution and optimize the non-execution speed of sql itself
(2) Roll back things if there is an exception
The reason for locking the table may be that the row data has been modified and forgotten Submitting will also cause the table to be locked.
Expand knowledge:
It is recommended to check the reason before making a decision when locking the table.
1 The code for lock table query has the following form:
select count(*) from v$locked_object; select * from v$locked_object;
2. Check which table is locked
select b.owner,b.object_name,a.session_id,a.locked_mode from v$locked_object a,dba_objects b where b.object_id = a.object_id;
3 Check which session caused it
select b.username,b.sid,b.serial#,logon_time from v$locked_object a,v$session b where a.session_id = b.sid order by b.logon_time;
Recommended tutorial: "Oracle Video Tutorial"
The above is the detailed content of Will insert in Oracle lock the table?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1798
16
1594
29
1475
72
267
587
How to uninstall MySQL and clean residual files
Apr 29, 2025 pm 04:03 PM
To safely and thoroughly uninstall MySQL and clean all residual files, follow the following steps: 1. Stop MySQL service; 2. Uninstall MySQL packages; 3. Clean configuration files and data directories; 4. Verify that the uninstallation is thorough.
Oracle's Role in the Business World
Apr 23, 2025 am 12:01 AM
Oracle is not only a database company, but also a leader in cloud computing and ERP systems. 1. Oracle provides comprehensive solutions from database to cloud services and ERP systems. 2. OracleCloud challenges AWS and Azure, providing IaaS, PaaS and SaaS services. 3. Oracle's ERP systems such as E-BusinessSuite and FusionApplications help enterprises optimize operations.
MongoDB vs. Oracle: Understanding Key Differences
Apr 16, 2025 am 12:01 AM
MongoDB is suitable for handling large-scale unstructured data, and Oracle is suitable for enterprise-level applications that require transaction consistency. 1.MongoDB provides flexibility and high performance, suitable for processing user behavior data. 2. Oracle is known for its stability and powerful functions and is suitable for financial systems. 3.MongoDB uses document models, and Oracle uses relational models. 4.MongoDB is suitable for social media applications, while Oracle is suitable for enterprise-level applications.
MongoDB vs. Oracle: Choosing the Right Database for Your Needs
Apr 22, 2025 am 12:10 AM
MongoDB is suitable for unstructured data and high scalability requirements, while Oracle is suitable for scenarios that require strict data consistency. 1.MongoDB flexibly stores data in different structures, suitable for social media and the Internet of Things. 2. Oracle structured data model ensures data integrity and is suitable for financial transactions. 3.MongoDB scales horizontally through shards, and Oracle scales vertically through RAC. 4.MongoDB has low maintenance costs, while Oracle has high maintenance costs but is fully supported.
Centos options after stopping maintenance
Apr 14, 2025 pm 08:51 PM
CentOS has been discontinued, alternatives include: 1. Rocky Linux (best compatibility); 2. AlmaLinux (compatible with CentOS); 3. Ubuntu Server (configuration required); 4. Red Hat Enterprise Linux (commercial version, paid license); 5. Oracle Linux (compatible with CentOS and RHEL). When migrating, considerations are: compatibility, availability, support, cost, and community support.
Can vscode run kotlin
Apr 15, 2025 pm 06:57 PM
Running Kotlin in VS Code requires the following environment configuration: Java Development Kit (JDK) and Kotlin compiler Kotlin-related plugins (such as Kotlin Language and Kotlin Extension for VS Code) create Kotlin files and run code for testing to ensure successful environment configuration
What software is better for yi framework? Recommended software for yi framework
Apr 18, 2025 pm 11:03 PM
Abstract of the first paragraph of the article: When choosing software to develop Yi framework applications, multiple factors need to be considered. While native mobile application development tools such as XCode and Android Studio can provide strong control and flexibility, cross-platform frameworks such as React Native and Flutter are becoming increasingly popular with the benefits of being able to deploy to multiple platforms at once. For developers new to mobile development, low-code or no-code platforms such as AppSheet and Glide can quickly and easily build applications. Additionally, cloud service providers such as AWS Amplify and Firebase provide comprehensive tools
MySQL vs. Oracle: Licensing, Features, and Benefits
May 08, 2025 am 12:05 AM
The main difference between MySQL and Oracle is licenses, features, and advantages. 1. License: MySQL provides a GPL license for free use, and Oracle adopts a proprietary license, which is expensive. 2. Function: MySQL has simple functions and is suitable for web applications and small and medium-sized enterprises. Oracle has powerful functions and is suitable for large-scale data and complex businesses. 3. Advantages: MySQL is open source free, suitable for startups, and Oracle is reliable in performance, suitable for large enterprises.
