The following major features are new in this release:

• Deferred inserts

  Applications can stream single-row inserts into special buffers stored in the large pool. The inserts are “deferred” because the database writes these buffers to data files asynchronously. The inserts are committed automatically and cannot be rolled back.

  See "Large Pool Buffers for Deferred Inserts".

• Hybrid partitioned tables

  A table can contain internal and external partitions. Internal partitions consume space inside the database (segments). External partitions are stored outside the database using external table functionality. For example, a sales table might contain two partitions stored in data files and three partitions stored in text files.

  See "Segments for Partitioned Tables".

The following features are desupported in this release.

• Oracle Multimedia

  Starting in Oracle Database 19c, Oracle Multimedia is desupported. Unless deselected, the Oracle Multimedia component (ORDIM) in dba_registry displays as VALID in upgraded and newly created databases. Oracle Locator (installed with Oracle Multimedia if Spatial and Graph is not installed) continues to be installed and supported. Oracle recommends that you store multimedia content in SecureFiles LOBs, and use third-party products for image processing and conversion.

  See "SecureFiles".

• Oracle Streams

  Starting in Oracle Database 19c, Oracle Streams is desupported.

  See "Oracle GoldenGate".

The following major features are new in this release:

• Memoptimize pool

  Oracle Database supports high-performance reads for tables specified with the MEMOPTIMIZE FOR READ clause. The buffers are cached in a new area in the SGA called the memoptimize pool.

  See "Memoptimize Pool".

• Private temporary tables

  Private temporary tables are temporary database objects that are automatically dropped at the end of a transaction or a session. A private temporary table is stored in memory and is visible only to the session that created it. A private temporary table confines the scope of a temporary table to a session or a transaction, thus providing more flexibility in application coding, leading to easier code maintenance and a better ready-to-use functionality.

  See "Overview of Temporary Tables".

• Shadow lost write protection

  A lost write occurs when the database thinks it has written a block to storage, but the write did not occur. A shadow tablespace enables the database to catch the majority of lost writes without requiring the use of a standby database and without the possibility of cascading errors.

  See "Shadow Tablespaces".

The following features are deprecated in this release, and may be desupported in a future release:

• Oracle Multimedia

  Starting in Oracle Database 18c, Oracle Multimedia is deprecated. Oracle recommends that you store multimedia content in SecureFiles LOBs, and use third-party products for image processing and conversion.

  See "SecureFiles".