- What are triggers used for in MySQL?
- How do I trigger a track change in MySQL?
- Is MongoDB faster than MySQL?
- Which is better MongoDB or DynamoDB?
- What is the benefit of database?
- Why MyISAM gives the best performance?
- Why is MongoDB bad?
- What is advantage and disadvantage of database?
- When should you not use a DBMS?
- What are the advantages and disadvantages of using MySQL?
- What is the limitation of MySQL?
- What are the disadvantages of using a database?
- What are the advantages of using MySQL?
- What are the disadvantages of MongoDB?
- What is MySQL interview questions?
What are triggers used for in MySQL?
A trigger is a named database object that is associated with a table, and that activates when a particular event occurs for the table.
Some uses for triggers are to perform checks of values to be inserted into a table or to perform calculations on values involved in an update..
How do I trigger a track change in MySQL?
I’ll be using the following table as the source table to track the changes.CREATE TABLE data ( id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, … CREATE TABLE data_log ( action VARCHAR(255), … DELIMITER $$ CREATE TRIGGER ad_data AFTER DELETE ON data. … mysql> SELECT * FROM data_log;
Is MongoDB faster than MySQL?
MongoDB vs MySQL: Performance & Speed MongoDB: One single main benefit it has over MySQL is its ability to handle large unstructured data. It is magically faster. People are experiencing real world MongoDB performance mainly because it allows users to query in a different manner that is more sensitive to workload.
Which is better MongoDB or DynamoDB?
DynamoDB as an integrated AWS service makes it easier to develop end to end solutions. DynamoDB uses tables, items and attributes, MongoDB uses JSON-like documents. DynamoDB supports limited data types and smaller item sizes; MongoDB supports more data types and has fewer size restrictions.
What is the benefit of database?
Database benefits reduce the amount of time you spend managing data. analyse data in a variety of ways. promote a disciplined approach to data management. turn disparate information into a valuable resource.
Why MyISAM gives the best performance?
MyISAM is designed with the idea that your database is queried far more than its updated and as a result it performs very fast read operations. If your read to write(insert|update) ratio is less than 15% its better to use MyISAM.
Why is MongoDB bad?
You may end up having a lot of duplicate data, as MongoDB does not support well-defined relationships. Updating this duplicate data can be hard and, also due to lack of ACID compliance, we might end up having corrupted data.
What is advantage and disadvantage of database?
Increased costs one of the disadvantages of dbms is Database systems require sophisticated hardware and software and highly skilled personnel. The cost of maintaining the hardware, software, and personnel required to operate and manage a database system can be substantial.
When should you not use a DBMS?
When a DBMS may be unnecessary: If the database and applications are simple, well defined, and not expected to change. If there are stringent real-time requirements that may not be met because of DBMS overhead. If access to data by multiple users is not required.
What are the advantages and disadvantages of using MySQL?
Advantages Of Using MySQLIt’s Easy To Use. … Support Is Readily Available Whenever Necessary. … It’s Open-Source (Sort Of) … It’s Incredibly Inexpensive. … It’s An Industry Standard (And Still Extremely Popular) … It’s Got A Few Stability Issues. … It Suffers From Relatively Poor Performance Scaling.More items…•
What is the limitation of MySQL?
A table cannot contain more than 1000 columns. The internal maximum key length is 3500 bytes, but MySQL itself restricts this to 1024 bytes. The maximum row length, except for VARCHAR , BLOB and TEXT columns, is slightly less than half of a database page. That is, the maximum row length is about 8000 bytes.
What are the disadvantages of using a database?
DisadvantagesDatabase systems are complex, difficult, and time-consuming to design.Substantial hardware and software start-up costs.Damage to database affects virtually all applications programs.Extensive conversion costs in moving form a file-based system to a database system.Initial training required for all programmers and users.
What are the advantages of using MySQL?
8 Major Advantages of Using MySQLData Security. … On-Demand Scalability. … High Performance. … Round-the-clock Uptime. … Comprehensive Transactional Support. … Complete Workflow Control. … Reduced Total Cost of Ownership. … The Flexibility of Open Source.
What are the disadvantages of MongoDB?
Disadvantages of MongoDBMongoDB uses high memory for data storage.There is a limit for document size, i.e. 16mb.There is no transaction support in MongoDB.
What is MySQL interview questions?
Top 50 MySQL Interview Questions & AnswersWhat is MySQL? … What are the technical features of MySQL? … Why MySQL is used? … What are Heap tables? … What is the default port for MySQL Server? … What are the advantages of MySQL when compared with Oracle? … Differentiate between FLOAT and DOUBLE? … Differentiate CHAR_LENGTH and LENGTH?More items…•