sql function - How does SQL server treat text comparisons with LEADING spaces -

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much made (and able found on internet) how not need use where rtrim(columnname) = 'value' in sql server, because automatically considers value or without trailing spaces same.

however i've had hard time finding info leading spaces. if (for whatever reason) our data warehouse has leading spaces on varchar / char type of fields , need have clauses - still need ltrim() ? i'm trying avoid big performance hit researching out other options. thank you

leading spaces never ignored in comparisons of text based data type. if comparing equality of text columns, best option validate values on data entry make sure text unwanted spaces in front not allowed. example if database expecting user type list of possible values database application expecting, not allow user interfaces let users enter text free-form, force them enter 1 of explicit valid values. if need user able enter free-form text never want leading spaces, strip them on insert. normalizing database should prevent lot of these types of issues.


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