If you are looking to check for whether the values in a column are numeric, REGEXP_LIKE will help you to compare the values of the column with the pattern for numeric values. For example, the query below returns all the values in the field which match the regular expression for numeric values (including decimals)
`select field from table where field REGEXP_LIKE '^[1-9]\d*(\.\d+)?$'`
You could further modify the query if you wish to return only values specific to a particular record or go further to check whether a null value is returned (which would mean that the field has non numeric value). I would recommend that you check out https://community.denodo.com/docs/html/browse/6.0/vdp/vql/language_for_defining_and_processing_data_vql/comparison_operators/comparison_operators and https://community.denodo.com/docs/html/browse/6.0/vdp/vql/appendix/syntax_of_condition_functions/other_functions to build your query.
Hope this helps!