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CDC and DataStage. My experience.

IBM Change Data Capture previously known as DataMirror is a Data replication tool and the latest version comes with ETL capabilities as well. Main use of this tool is to move data from one database to another (within a database or between two databases).
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How to prepare for DataStage Interview - Part 1

There are many friends who are trying to crack down DataStage interviews but somehow because of lack of real world project exposure; not able to make it through. The tips explained below are to help them so that they can be confident while perusing interview and prepare in a way that they are capable of handling any kind of question and answers them tactfully.

Incremental or delta load in DataStage

Incremental loading in the DataStage can be performed by using the Change Data Capture stage. This is a stage which takes sorted input on the key fields and generates a change code which denotes the type of change. Based on change code required DMLs can be performed on target database. Following figure can explain the basic design of a CDC stage:

DataStage String Functions

Following is the list of DataStage String Functions

FunctionUsageAlNumCab be used to check if the given string has alphanumeric charactersAlphaTRUE if string is completely alphabeticCompactWhiteSpaceall consective whitespace will be reduced to single spaceCompareCompares two strings for sortComparNoCaseCompare two strings irrespective of Case in-sensitiveness ComparNumCompare the first n characters of the two stringsCompareNumNoCaseCompare first n characters of the two strings irrespective of case in-sensitivenessConvertReplace character in a string with the given character.CountCount number of times a given substring occurs in a stringDcountReturns count of delimited fields in a stringDownCaseChange all uppercase letters in a string to lowercaseDQuoteEnclose a string in double quotation marksFieldReturn 1 or more delimited substringsIndexFind starting character position of substringLeftFinds leftmost n characters of stringLenLength of the string or total number of characters in a stri…