Changes in This Release for Oracle Database Development Guide
This is a summary of important changes in Oracle Database 23ai for Oracle Database Development Guide.
New Features in 23ai
The following are the new features in Oracle Database Development Guide for Oracle Database Release 23ai.
Blockchain Table Log History
This feature allows changes to one or more regular user tables to be tracked in a blockchain table, which is maintained by Oracle Database as part of the Flashback Data Archive.
Data Use Case Domains
A data use case domain is a dictionary object that belongs to a schema and encapsulates a set of optional properties and constraints for common values, such as credit card numbers or email addresses. After you define a data use case domain, you can define table columns to be associated with that domain, thereby explicitly applying the domain's optional properties and constraints to those columns.
Flashback Time Travel Enhancements
Flashback Time Travel can automatically track and archive transactional
changes to tables. Flashback Time Travel creates archives of the changes made to the
rows of a table and stores the changes in history tables. It also maintains a history of
the evolution of the table's schema. By maintaining the history of the transactional
changes to a table and its schema, Flashback Time Travel enables you to perform
operations, such as Flashback Query AS OF and
VERSIONS), on the table to view the history of the changes made during
transaction time.
IF [NOT] EXISTS Syntax Support
DDL object creation, modification, and deletion now support the IF
EXISTS and IF NOT EXISTS syntax modifiers. This enables
you to control whether an error should be raised if a given object exists or does not
exist.
The IF [NOT] EXISTS syntax can simplify error handling in
scripts and by applications.
Implicit Connection Pooling for Database Resident Connection Pooling
This feature enables the automatic assignment of Database Resident Connection Pooling (DRCP) servers to and from an application connection at runtime when the application starts and finishes database operations, even if the application does not explicitly close the connection.
This feature can provide better scalability and efficient usage of database resources for applications that do not use application connection pooling.
Lock-Free Reservation
Lock-free Reservation enables concurrent transactions to proceed without being blocked on updates of heavily updated rows. Lock-free reservations are held on the rows instead of locking them. Lock-free Reservation verifies if the updates can succeed and defers the updates until the transaction commit time.
Lock-free Reservation improves the end user experience and concurrency in transactions.
Multilingual Engine JavaScript Modules and Environments
Multilingual Engine (MLE) Modules and Environments allow JavaScript code to persist and be managed in the database. Call specifications provide a means to call JavaScript functions from an MLE module, anywhere that you can call PL/SQL functions.
The introduction of JavaScript Modules and Environments as schema objects in Oracle Database allows developers to follow established and well-known workflows used in client-side JavaScript development. Complex projects can be broken down into smaller, more manageable pieces that can be worked on independently by team members.
Multiple Named Pools for DRCP
Database Resident Connection Pooling (DRCP) now supports multiple named pools. The
DBMS_CONNECTION_POOL.ADD_POOL() and
DBMS_CONNECTION_POOL.REMOVE_POOL() procedures are added to the
DBMS_CONNECTION_POOL package. Oracle Net connection string syntax
is enhanced, so you can specify a pool name for each connection. Existing procedures can
be used to start, stop, or configure named pools.
Having multiple pools allows finer control on the DRCP pool usage. It helps prevent situations where some applications dominate the use of a single pool.
Precheckable Constraints using JSON Schema
A check constraint can be checked outside the database. For this, you mark
the check constraint with the PRECHECK keyword. You can create a JSON
Schema document from a precheckable check constraint. This means that data can be
checked for validity outside of the database using an external JSON Schema
validator.
A JSON schema can describe rules that define valid data (rules that correspond to the check constraint). This lets you use the database as a central repository of business rules.
A JSON schema can be used to check data (in application code, for instance) prior to sending it to the database, which can provide earlier detection of invalid data. This provides more resilient applications and reduces potential system downtime and the need to clean up 'bad' data.
Reset Database Session State
The reset session state feature clears the session state set by the application when
the request ends. The RESET_STATE database service attribute cleans up
dirty sessions so that the applications cannot see the state of these sessions. This
feature applies to all applications that connect to the database using database
services.
The RESET_STATE feature enables you to clean the session state at the
end of each request so that the database developers do not have to clean the session
state manually. By using this feature, you can ensure that there are no data leaks from
a previous session.
See Reset Database Session State to Prevent Application State Leaks.
Saga APIs Using Oracle Saga Framework
Oracle Saga APIs are implemented in the database and provide a framework to implement transactional semantics for microservices built with Oracle Database. The orchestrator Saga framework provides a way to maintain atomic data consistency across microservices.
Sagas are concurrent and execute local transactions in each participant database making it more efficient than distributed ACID transactions, thereby simplifying application code and increasing developer productivity.
Schema Annotations
Schema annotations enable you to store and retrieve metadata about database objects. These are name-value pairs or simply a name. These are freeform text fields applications can use to customize business logic or user interfaces.
Schema annotations help you use database objects in the same way across all applications. This simplifies development and improves data quality.
See Schema Annotations.
Shut Down Connection Draining for DRCP
A new, optional DRAINTIME argument to
DBMS_CONNECTION_POOL.STOP_POOL() allows active DRCP pools to be
closed after a specified connection drain time, or be closed immediately without waiting
for connections to be idle. This feature gives DBAs better control over DRCP usage and
configuration.
Deprecated Features
This section lists the deprecated features in Oracle Database release 23ai, version 23.3 for Database Development Guide.
Oracle recommends that you do not use deprecated features/values in new applications. Support for deprecated features is for backward compatibility only.
Deprecation of Traditional Audit Initialization Parameters
With the desupport of creating and modifying traditional audit policies with Oracle Database 23, the traditional audit parameters are deprecated.Traditional audit policies are available after upgrading, but the initialization parameters associated with those policies are deprecated. These deprecated parameters include the following:
AUDIT_TRAILAUDIT_SYS_OPERATIONSAUDIT_FILE_DESTAUDIT_SYSLOG_LEVEL
Oracle recommends that you migrate to unified auditing as soon as possible, because these traditional audit parameters can be removed in a future database release.