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How to get the length of a CLOB column

This tip is very useful if you need to check the length of a CLOB column in an Oracle table.

This tip is very useful if you need to check the length of a CLOB column in an Oracle table since the normal length...

function does not work on a CLOB column. Many people write their own routines or use other lengthy methods to get the length of a CLOB column. This tip makes it easier. It has been tested on Oracle 8.1.7 on Sun Solaris.

You can get the length of CLOB column data for a particuler record directly by using the dbms_lob package provided by Oracle. For example, create a table called MYTAB with column col1 with datatype CLOB. Then insert one record into MYTAB. Now let's say that you want to know the length of col1 data. To get it, use the following query:

select dbms_lob.getlength(col1) from mytab;

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If you have more than one record then you have to use another key to restrict the fetch.

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