Certification

Oracle Certification Notes: Part XI

This is a continuation of my notes as I study for the Oracle Certified Associate credential: Grouping Functions COUNT(*) is the same as COUNT(ALL column) Group functions ignore NULL values unless otherwise handled with NVL functions; As an example, this concept is important when using AVG() Statistical group functions include VARIANCE() and STDDEV() Group functions …

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Oracle Certification Notes: Part X

Here is a continuation of my notes as I study for the Oracle Certified Associate credential: Character Conversion Functions NVL2(value, if_not_null, if_null): Watch out that the 2nd parameter after the compared value is if_NOT_null NULLIF(if_not_equal, compare_value): IF compare_value equals if_not_equal THEN return null; ELSE return if_not_equal; COALESCE(if_not_null_1, if_not_null_2, … if_not_null_n): Like using nested NVL() statements. …

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Oracle Certification Notes: Part IX

A continuation of my notes as I study for the Oracle Certified Associate credential. In this post, I’ve simply referenced available Oracle Functions and associated examples. For a more appropriate description, please view the Oracle Documentation Library. Function:ROUND(number, precision) select round(1631.7344,−3) from dual is 2000. select round(1331.7344,−3) from dual is 1000. select round(1631.7344,−4) from dual …

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Oracle Certification Notes: Part VIII

A continuation of my notes as I study for the Oracle Certified Associate credential: Comparison Operators For character and date comparisons, each side of the comparison operator is converted into its numeric representation, and then compared. The numeric value is based on the database characterset. != and <> are equivalent inequality operators LIKE command has …

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Oracle Certification Notes: Part VI

A continuation of my notes as I study for the Oracle Certified Associate credential: Tablespace A tablespace contains one or more segments (e.g., table segment, index segment, undo segment), which are contained on one or more database files Tablespaces are a method of organizing physical database files with logical segments At a minimum, 2 tablespaces …

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Oracle Certification Notes: Part V

A continuation of my notes as I study for Oracle’s Certified Associate credential: Instance vs. Database Traditionally a one-to-one relationship between instance and database Oracle Real Application Clusters (RAC): Multiple instances on different servers pointing to a single database. An instance may point to multiple databases through the use of database links. Instance: Memory structure …

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