Metric used in MYSQL Spatial

[AJAY WARRIER]

I am trying to determine the metric system for MySQL Spatial 5.6.12.

For example, I have the following table that created to store point geometry for multiple records.

CREATE TABLE POINTS_DATA(
RECORD_ID INT(15),
STREET_ADDRESS VARCHAR(50),
CITY VARCHAR(50),
STATE VARCHAR(25),
ZIPCODE VARCHAR(11),
LOCATION_GEO_CODES_SDO POINT NOT NULL,
SPATIAL INDEX(LOCATION_GEO_CODES_SDO),
PRIMARY KEY(RECORD_ID)
) ENGINE=MyISAM;

After the table was created , I inserted some records into the table successfully.

Now I have constructed the following query to fetch all the records that are within one mile from a specified LAT/LONG. Here is the query I run for that.

SELECT RECORD_ID, STREET_ADDRESS, CITY, STATE, ZIPCODE
, GLength(LineStringFromWKB(LineString(LOCATION_GEO_CODES_SDO
, POINT(-85.123,39.113))) AS DISTANCE
FROM POINTS_DATA
HAVING DISTANCE < 1 ORDER BY DISTANCE;

After running this query, I do get some records, but the distance does not seem to be in Miles or meters. ..its some fractional value like 0.0123, 0.0145...etc

I could not find any documentation on this anywhere in MySQL?. Does anyone know what metric system is in use in MySQL?..and if there is , how can I convert it into miles?

That means, if I need to run the query above to fetch all records within one mile, how do I reconstruct it?. Thanks in advance.