Extended Data Types in Oracle Database 12c

Prior to Oracle 12c, regardless of the character semantics used, the maximum size of a VARCHAR2, NVARCHAR2 and RAW columns in a database are as follows. ◉ VARCHAR2 : 4000 bytes ◉ NVARCHAR2 : 4000 bytes ◉ RAW : 2000 bytes With the introduction of Extended Data Types,...

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Row Limiting Clause for Top-N Queries in Oracle Database 12c

1. Introduction A Top-N query is used to retrieve the top or bottom N rows from an ordered set. Combining two Top-N queries gives you the ability to page through an ordered set. This concept is not a new one. In fact, Oracle already provides multiple ways to...

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Recovery Manager (RMAN) Table Point In Time Recovery (PITR) in Oracle Database 12c

In previous releases point in time recovery of a table or table partition was only possible by manually creating a point in time clone of the database, retrieving the table using data pump, then removing the clone. Oracle 12c includes a new RMAN feature which performs all these...

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Recovery Manager (RMAN) Database Duplication Enhancements in Oracle Database 12c

The Recovery Manager (RMAN) DUPLICATE command has been available since at least Oracle 8i, allowing you perform backup-based duplications of database. Oracle 11g introduced the concept of active database duplicates, allowing database duplication without the need for additional backups. Active Database Duplication using Backup Sets In previous releases,...

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Extended Data Types in Oracle Database 12c

Prior to Oracle 12c, regardless of the character semantics used, the maximum size of a VARCHAR2, NVARCHAR2 and RAW columns in a database are as follows. ◉ VARCHAR2 : 4000 bytes ◉ NVARCHAR2 : 4000 bytes ◉ RAW : 2000 bytes With the introduction of Extended Data Types,...

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Data Pump (expdp, impdp) Enhancements in Oracle Database 12c

Oracle Data Pump was introduced in Oracle 10g. This article provides an overview of the main Data Pump enhancements in Oracle Database 12c Release 1, including the following. ◉ NOLOGGING Option (DISABLE_ARCHIVE_LOGGING) The TRANSFORM parameter of impdp has been extended to include a DISABLE_ARCHIVE_LOGGING option. The default setting...

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Automatic Diagnostics Repository (ADR) Enhancements in Oracle Database 12c (ADRCI)

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The basic concepts of the Automatic Diagnostics Repository (ADR) remain unchanged in Oracle Database 12c, but there have been several notable changes to the way the diagnostics information is handled. ◉ DDL Log Setting the ENABLE_DDL_LOGGING parameter to TRUE activates DDL logging. All DDL statements are logged into...

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Database Migration Assistant for Unicode (DMU) in Oracle Database 12c

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The Database Migration Assistant for Unicode (DMU) is listed as a 12c new feature, but it is actually a separate tool that supports a number of different database versions. Download Version 1.2 of the DMU is shipped with the 12c database. You can see it by running the...

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