Pages having OLTP tag
Concurrency Control of Transaction is implemented by records cache. This page explains how the cache is used.
Record Caches for Each Transaction
Record Caches are used to check which records are updated by local transaction.
Fast Concurrency Control
Alinous Elastic DB does not update data in the storage engine before committing the transaction.
Read "Execute Transaction Concurrently with Record Cache" more
Relational Database Management System has isolation levels. Alinous Elastic DB has 2 isolation levels, SERIALIZABLE and READ COMMITTED. They are different feature, and suitable usage.
Feature of Isolation Levels
The transaction of each isolation level executed different way in locking. Therefore their performance and way to keep consistency is different.
READ COMMITTED is the default isolation level, and it is best way to OLTP applications.
Read "Feature of Serializable & Read Committed Isolation Level" more
In order to make Distributed Database, especially Transactional RDBMS (Relational Database) supports remote transaction, fast, there are some points to solve.
Why Distributed Database is High Speed
Generally, distributed database is good at high scalability & high throughput. That is because it has some network nodes, and the CPUs in them works simultaneously.
The query benchmark is very fast, if it is independent task. As you add nodes, the number of transactions executed is linearly increases.
Weak Points of Distributed Database
But in actual use, it does not work like benchmark. It has some weak points.
Read "Distributed Transaction Performance for Scalability & Speed" more
NewSQL is database management system which have more functions than RDBMS. It has distributed data management functions, that NoSQL is good at. Alinous Elastic DB is a kind of NewSQL.
Use Case of Bigdata
BigData is not simply huge data. That is high resolution data.
Data Acquisition Changes
Recently, IoT (Internet of Things) is a trending keyword. The IoT products generates a lot of data.
That is because the way to acquire data is changed by it. It takes a lot of detailed information as huge logs. As time passed, the data become bigger and bigger.
Read "NewSQL for OLTP & Bigdata" more
The Storage Engine of Distributed Database has records in it. The format have to resolve ACID status with the record's information.
Especially on using partitioning, the format is very important to make the performance high.
Data Format of Storage Records
There are two types of policies in database records management supporting ACID. When the records are changed, one of following operations are done.
- Update or Delete the record
- Add a new record with new version
MySQL uses the first method, and PostgreSQL uses second one. The Alinous Elastic DB uses the second method like PostgreSQL.
Read "Storage Records Data Format for Partitioning" more