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[Enmo College] Classic documentation: Oracle Database 12.2 New Features Overview interpretation and download

Gai Guoqiang

With regard to the In-Memory option, an important enhancement of 12.2 is the implementation of In-Memory caching in ADG, which can be compressed in different intervals from the main library, and carry OLAP analysis and calculation through the memory of the standby library. Real-time computing can be better and better supported in Oracle database.

In 12.2, the In-Memory Fast-Start feature supports storing data in IM compressed format on persistent storage so that it can be loaded quickly without having to recompress when the database is restarted. This feature can speed up the initialization of data compression by 2-5 times.

Faster In-Memory Joins, join specific columns by creating Join Group, share compression dictionary, and improve performance:

Improved index compression ratio, for example, an uncompressed index may take up 1.2 TB space, while under low compression ratio, it takes up 679 GB space, while under the new feature high compression, only 270 GB is needed, which not only saves storage space, but also improves performance. Index usage tracking is also optimized in 12.2:

A large number of enhancements have been made to the core database functions, such as support for ultra-long identifiers, which now has 128bits, and AL32UTF8 has become the default character set for the database, improving the ability to support global characters:

The approximate query function provided in 12.1 is further enhanced, and further flexible control can be achieved through the parameters APPROX_PERCENTILE and APPROX_MEDIAN parameters in 12.2 to avoid complex rewriting of the application:

In terms of multi-tenancy, support for PDB has increased from 252 to 4096 in a single CDB, and features such as online cloning, refresh, and migration are supported:

PDB supports online cloning, and then continuously refreshes the data to keep the clone library and source database in sync:

When a complete conversion is required, the source library can be migrated to a new location through Relocate:

Of course, the 12.2 Sharding is also eye-catching, with up to 1000 shards, which can transform the Oracle database into a distributed architecture, using Shard-Nothing mode, and providing linear scalability:

In 12.2, Data Guard technology has made many enhancements, the most important of which is the parallel multi-instance recovery ability, which greatly improves the synchronization efficiency of Data Guard.

The support of Nologging feature is also a very eye-catching practical feature. In the past, if the data was loaded in the main database using Nologging, the slave database could not synchronize the data, and the query would trigger errors. In 12.2, these loaded data blocks will be recorded in the control file. In the slave database, you can simply execute RECOVER DATABASE NONLOGGED BLOCK through RMAN to quickly recover these data and complete data correction:

A large number of maintenance operations are further automated and Onlinealized, such as Move data tables, which convert non-partitioned tables into partitioned tables:

In the process of continuous innovation, Oracle database has surpassed the CS era, the Internet era, and entered the current cloud era. Oracle has also kept up with the times through continuous enhancement of new features, and once again leads the trend of databases:

Enmo College, a subsidiary of Yunhe Enmo (Beijing) Information Technology Co., Ltd., is committed to providing professional and high-level oracle database and big data training services, mining and training big data and database talents. Enmo College provides a full range of big data and database technology training, including individual practical skills training, personal certification training, and enterprise internal training. ACE-level super teachers, equipped with professional laboratories, immersion learning and training, professional laboratories, equipped with professional teaching assistants to guide training. Can quickly integrate into the circle of experts, rich in resources in the industry, and quickly accumulate workplace contacts. Oracle database courses include: Oracle DBA practical class, Oracle OCM examination, Oracle OCP examination and so on.

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