The code snippet `dpg2_seg&'|'&geo as DPGGeoKey` appears to be creating...

The code snippet dpg2_seg&'|'&geo as DPGGeoKey appears to be creating a new field or variable called DPGGeoKey by concatenating two existing fields or variables: dpg2_seg and geo. It uses the & operator to combine them, with the string '|' (a vertical bar) added as a delimiter between the two values.

Step-by-step:

1. dpg2_seg - This is one of the fields/variables.
2. '|' - A string literal (vertical bar) used as a delimiter.
3. geo - Another field/variable.
4. & - The concatenation operator that combines the parts into a single string.
5. as DPGGeoKey - Aliases the resulting concatenated value as DPGGeoKey.

Example:

If dpg2_seg has a value of "A1" and geo has a value of "RegionX", the resulting value of DPGGeoKey would be:

"A1|RegionX"

This is likely used to create a composite key or a unique identifier by combining these two fields with a delimiter.