#20 Oracle Database 21C World’s best and new age RDBMS

Oracle Database 21c is World’s best-converged database that comes up with 200+ new features for all data-driven application use cases

Oracle Database 21c

Oracle Database 21c

World’s most popular Oracle database has come up with major upgrade in its database 21c. With this launch RDBMS is back in the game and challenging the use cases where NoSQL was supposed to be the best fit. New age RDBMS Oracle database 21c contains more than 200 new innovations including in-database machine learning AutoML, immutable blockchain table, graph processing optimization, in-memory optimization, JavaScript support, dramatic improvement to JSON operations, sharding, multitenant, security and many more.

Oracle database 21c is available on Oracle cloud and can be deployed as a Database Service Virtual Machine (for clusters and single instance) or Bare Metal service (single instance). It is also available with Oracle Cloud always free tier of Oracle Autonomous database with limited storage and CPU capacity. In addition, Oracle APEX (Application Express) Application Development is also available with Oracle database which is a new low-code service for developing and deploying data-driven enterprise applications quickly and easily.

Data-Driven Future

Oracle has consistently worked on managing and storing data in converged database which is more efficient and productive than breaking up into multiple single-use engines. Converged database addresses the data integrity, consistency and security issues. Now, let’s understand what is Converged database? A converged database is a multi-model, multitenant, multi-workload database. It supports the data model and access method each development team wants, without unneeded functionality getting in the way. It provides both the consolidation and isolation these different teams want but don’t want to think about. And it excels in all the workloads (like OLTP, analytics, and IoT) these teams require. Oracle Database 19c is the world’s first converged database.

Figure 1 Converge Oracle Database

Oracle database 21c has put more innovation to Oracle’s converged database and  offers: best of breed support for all data types (e.g. relational, JSON, XML, spatial, graph, OLAP, etc.), and industry-leading performance, scalability, availability and security for all their operational, analytical and other mixed workloads. Oracle’s converged strategy also ensures that developers benefit from all Oracle Database 21c key capabilities (e.g. ACID transactions, read consistency, parallel scans and DML, online backups, etc.) – freeing them to focus on developing applications without having to worry about data persistence.

Figure 2 Multi-model innovation – Oracle Database

What’s new in Oracle Database 21c

This latest Innovation release introduces several new features and enhancements that further extend database use cases, improves developer, analyst and data scientist productivity, and increases query performance.  Listed below is a subset of what’s new in Oracle Database 21c.

New Blockchain Tables

Blockchain as a technology has promised much in terms of solving many of the problems associated with the verification of transactions. While considerable progress has been made in bringing this technology to the enterprise, several problems exist. Arguably, the largest being the complex nature of building applications that can support a distributed ledger. Oracle Database 21c addresses this problem with the introduction of Blockchain Tables. These tables operate like any normal heap table, but with a few important differences. The most notable of these being that rows are cryptographically hashed as they are inserted into the table, ensuring that the row can no longer be changed later.

Figure 3 Blockchain Table – Oracle Database

New Native JSON Datatype

Oracle Database has had JSON support since version 12c and storing JSON data as a VARCHAR2 or a LOB (CLOB or BLOB). In Oracle Database 21c, JSON support is further enhanced by offering a native data type, “JSON”. This means that instead of having to parse JSON on read or update operations, the parse only happens on an insert and the JSON is then held in an internal binary format which makes access much faster. This can result in read and update operations being 4 or 5 times faster and updates to very large JSON documents being 20 to 30 times faster.

Figure 4 Native JSON Datatype
Figure 5 function JSON_TRANSFORM

JSON Performance in Oracle Database

Here is comparison of Oracle database performance with Mongodb  

Text Box: Autonomous JSON Database with 8 OCPUs compared to MongoDB Atlas on M60
Industry-standard Yahoo Cloud Serving Benchmark (YCSB)
Source of MongoDB results: https://www.mongodb.com/atlas-vs-amazon-documentdb/performance as of 8/12/2020

New JavaScript Execution inside the Database

Oracle Database 21c adds support for JavaScript via the Oracle Multilingual Engine (MLE), powered by GraalVM. JavaScript is a ubiquitous scripting language that, among its many uses, enables richer user interaction in web applications and mobile apps. It’s one of the few languages that runs in a web browser and can be used to develop both client-side and server-side code. There is a large collection of existing JavaScript libraries for implementing complex programs, and JavaScript works in conjunction with popular development technologies such as JSON and REST. The MLE automatically maps JavaScript data types to Oracle Database data types and vice versa. The JavaScript code itself can execute PL/SQL (stored procedures) and SQL through a built-in JavaScript module.

Figure 6 JavaScript Execution in Oracle Database

More Innovations to Support Multi-Workload

Figure 7 Multi-workload – Oracle Database

In-Memory improvement

Database In-Memory requires a lot of manual effort from DBAs, developers and users. Now you can set INMEMORY_AUTOMATIC_LEVEL to HIGH, and all columns will be considered for in-memory analysis.

Also, in-memory hash joins have been optimized using SIMD vectorization, resulting in up to 10x higher speed. Also, columnar scans have been sped up for the case where not every column is in memory. Now, the optimizer can perform a hybrid scan and fetch projected column values from the row store if needed, instead of needing to perform the scan entirely on the row store.

Figure 8 In-Memory Column Store – Oracle Database

Persistent Memory Store

“Dramatic performance improvement for I/O-bound workloads”

Oracle Database 21c added support for a Persistent Memory (PMEM) store on single instance databases. This allows for storage of data and redo in local PMEM on commodity hardware. Oracle Database 21c runs SQL directly on data stored in the mapped PMEM file system, eliminating the need for a large buffer cache and reduces the code path. And it provides much faster transaction durability and near-instant recovery. This feature is especially useful for workloads that tend to be I/O bound.

Figure 9 Persistent Memory Store – Oracle Database


Oracle Database 21c makes it even simpler for data scientists and analysts to take advantage of in-database machine learning by providing Python machine learning interfaces to the database. This new client tool complements existing R and SQL interfaces already available. AutoML simplifies the development of predictive machine learning models by automating the model selection, feature selection, and parameter tuning processes required for building accurate models.

Automatically build and compare Machine Learning models

Figure 10 AutoML

More Innovations to Support Multi-Tenant

Figure 11 Multi-Tenant

An Oracle database is a multi-tenant container database (CDB) that holds one system seed pluggable database and any number of user-created pluggable databases (PDBs). (See the third diagram below.) Users interact only with the PDBs, and a user may never realize that the PDB they are using isn’t a standalone database. In the past, Oracle also supported non-CDB database instances, but that option is no longer supported in Oracle Database 21c.

Multi-tenant Enhancement

Figure 12 Data Guard Per-PDB Physical Standby


DbNest provides Enhanced Security Isolation for both Container and Pluggable Databases. CDBs and PDBs each reside within their own security realms called a “Nest”, which are enforced using advanced O/S features. DbNest provides security isolation of following

  • Processes
  • CPU
  • Memory
  • Network
  • File access
Figure 13 DbNest


Oracle Database 21c is World’s best-converged database that comes up with 200+ new features for all data-driven application use cases. Please explore more exciting features ( https://docs.oracle.com/en/database/oracle/oracle-database/21/whats-new.html ) listed here and experience the new age RDBMS.

Oracle Database 21c More Features



Explore more at Teknonauts.com

Leave a Reply

Your email address will not be published. Required fields are marked *