Month: November 2018

Oracle nvl2 function

Description: The Oracle NVL2 function extends the functionality of NVL function.  NVL2 function lets you substitutes values for both null and non-null values encountered. Syntax: NVL2( arg1, value_when_not_NULL, value_when_NULL ) arg1:   The string to test for a null value.value_when_not_NULL:   The value returned if string1 is not null.value_when_NULL:   The value returned if string1 …

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SELECT Statement Basics

Basic SELECT Syntax: SELECT   EmpNo, EName    => select_list   /    which columns. FROM       scott.emp;              => data_source /  which table / view / other datasource.  SELECT Query:      It is an operation that retrives data from one or more data sources like: TABLE  / VIEW / MATERIALIZED VIEW. Prerequisites:      The user must have the SELECT priviledges …

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High Level Watermark, PCTFREE and PCTUSED

High Level Watermark(HLW) in datablock: High Level Watermark is a term used with table segment in DB to show the amount of datablock occupied(level) by the table data. As per PCTUSED and PCTFREE mentioned for datablock, the data will fillup in datablocks. When a table created(without data), the High Level Watermark will be on left most datablock(consider the datablocks arrange horizontally). After inserting few records, it fills few datablock, …

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About us

“Database Concepts Made Easy”, is the platform to get a better and easy way of understanding related to DATABASE concepts. It will be helpful for Students and Professionals to get into Database domain conceptually with realtime example and comparison of the concepts with multiple DBs. This blog drives its session flow as per next related concepts …

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