Tag: database

Oracle Database 18c: My preferred new features for DBAs

Oracle Databse 18c comes with some cool new features for DBAs. In this article I’ll list my preferred ones. Just one note: I think the name “Autonomous Database” is quite misleading, as it means that some of the new features COULD be used to configure your database as “autonomous” where previous versions required some maintenance,…
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18 Aprile 2018 0

Nested table

In PL SQL exists an efficient and adaptable collection of data: Nested table. Nested table is similar to one dimensional array but with some differences : An array has declare number of element – Nested table not. The size of nested table can increase using extend method. An array has always consecutive elements – Nested…
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2 Marzo 2017 0

Setup Oracle 12c Enterprise Manager Express for a PDB

There are many articles on the web explaining how to create, duplicate or plug/unplug a Pluggable Database (PDB) into a Container Database (CDB), e remarkable new feature in Oracle 12c Database. A few of them show how to open and use the Oracle 12c Enterprise Manager Express, the new web graphical administration application created “out-of-the-box”…
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4 Gennaio 2015 0

Index Tuning

Oracle indexes can be tuned looking to three main characteristics: SELECTIVITY: you can calculate index selectivity using this formula: SELECT DISTINCT_KEYS/NUM_ROWS SELECTIVITY FROM DBA_INDEXES / Values range from 0 to 1, where 1 is the optimal value (UNIQUE indexes and PK), while with values near to 0 performance is lower CLUSTERING FACTOR: measures how many…
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11 Dicembre 2013 0