NORMALIZE

Runs a normalization algorithm on an input relation. The output is a view with the normalized data.

Note: This function differs from NORMALIZE_FIT, which creates and stores a model rather than creating a view definition. This can lead to different performance characteristics between the two functions.

Syntax

NORMALIZE ( 'output‑view', 'input‑relation', 'input‑columns', 'normalization‑method'
           [ USING PARAMETERS [exclude_columns='excluded‑columns'] ] )

Arguments

output‑view	The name of the view showing the input relation with normalized data replacing the specified input columns. .
input‑relation	The table or view that contains the data to normalize. If the input relation is defined in Hive, use `SYNC_WITH_HCATALOG_SCHEMA` to sync the `hcatalog` schema, and then run the machine learning function.
input‑columns	Comma-separated list of numeric input columns that contain the values to normalize, or asterisk (*) to select all columns.
normalization‑method	The normalization method to use, one of the following: `minmax` `zscore` `robust_zscore` If infinity values appear in the table, the method ignores those values.

Parameter Settings

Parameter name	Set to…
`exclude_columns`	Comma-separated list of column names from input‑columns to exclude from processing.

Privileges

Non-superusers:

SELECT privileges on the input relation
CREATE privileges on the output view schema

Examples

These examples show how you can use the NORMALIZE function on the wt and hp columns in the mtcars table.

Execute the NORMALIZE function, and specify the minmax method:

=> SELECT NORMALIZE('mtcars_norm', 'mtcars',
                    'wt, hp', 'minmax');
        NORMALIZE
--------------------------
 Finished in 1 iteration

(1 row)

Execute the NORMALIZE function, and specify the zscore method:

=> SELECT NORMALIZE('mtcars_normz','mtcars',
                    'wt, hp', 'zscore');
        NORMALIZE
--------------------------
 Finished in 1 iteration

(1 row)

Execute the NORMALIZE function, and specify the robust_zscore method:

=> SELECT NORMALIZE('mtcars_normz', 'mtcars',
                    'wt, hp', 'robust_zscore');
        NORMALIZE
--------------------------
 Finished in 1 iteration

(1 row)