What is the most efficient way to query based on 3D Euclidean distance?

I have a MySQL table with X, Y, and Z coordinates. Each row of this table corresponds to a specific point in three space. Currentl开发者_如何学运维y, this data is stored as three separate integer columns, but I can change that if need be.

I want to query this table to find the closest point given the input point (x, y, z). One naive way to do this would be to select SQRT(POW((TableName.X - x), 2) + POW((TableName.Y - y), 2) + POW((TableName.Z - z), 2)) AS Distance for each row in the table, and then select the row that has the smallest Distance.

I know MySQL has a Point data type, but I'm not sure if that will help here. Does anyone know of an efficient way to calculate Euclidean distance? Thanks in advance.

Order by POW((TableName.X - x), 2) + POW((TableName.Y - y), 2) + POW((TableName.Z - z), 2) without the SQRT.

Since you only care about ordering, and the square root is monotone increasing, you can skip the square root. Without the SQRT, the math should be fast enough.