Grouping Parcels with an ID based on conditions, Query Speed assistance

Question

I have a table of 115,677 records. I am attempting to create a unique ID for groups of parcels that are owned by the same owner and are within 90 meters of each other. I determine if they are the same owner if the owner name column is the same or if the owner address column values are the same. Here's the SQL that I was able to get working for this:

ALTER TABLE parcel_owner_group_analysis
ADD COLUMN owner_group_id serial;

ALTER TABLE parcel_owner_group_analysis ALTER COLUMN owner_group_id DROP NOT NULL;

SELECT p1.objectid, p1.combined_owner_address, p1.combined_owner_name, p1.shape,
(
    SELECT min(p2.owner_group_id)
    FROM parcel_owner_group_analysis p2
    WHERE (
        (p1.combined_owner_name <> 'UNKNOWN' AND p2.combined_owner_name <> 'UNKNOWN' 
            AND p1.combined_owner_name = p2.combined_owner_name)
        OR (p1.combined_owner_address <> 'UNKNOWN' AND p2.combined_owner_address <> ('UNKNOWN')
            AND p1.combined_owner_address = p2.combined_owner_address)
    )
    AND ST_DWithin(p1.shape, p2.shape, 90) -- within 90 meters
) AS result_column
FROM parcel_owner_group_analysis p1;

The above takes 26 seconds to run on 115k records. Is there any way I can speed this up or do this better? There is a GIST index created on the geometry column (shape)

SRID: 3857. Any suggestions would be appreciated. Here is the EXPLAIN ANALYZE:

Seq Scan on parcel_owner_group_analysis p1  (cost=0.00..3598224.19 
rows=115677 width=359) (actual time=0.114..22288.375 rows=115677 
loops=1)
 SubPlan 1
 ->  Aggregate  (cost=31.04..31.05 rows=1 width=4) (actual 
 time=0.191..0.191 rows=1 loops=115677)
      ->  Bitmap Heap Scan on parcel_owner_group_analysis p2  
(cost=4.91..31.04 rows=1 width=4) (actual time=0.123..0.182 rows=2 
 loops=115677)
            Recheck Cond: (((p1.combined_owner_name)::text = 
 (combined_owner_name)::text) OR ((p1.combined_owner_address)::text 
 = (combined_owner_address)::text))
            Filter: (((((p1.combined_owner_name)::text <> 
 'UNKNOWN'::text) AND ((combined_owner_name)::text <> 
 'UNKNOWN'::text) AND ((p1.combined_owner_name)::text = 
 (combined_owner_name)::text)) OR 
 (((p1.combined_owner_address)::text <> 'UNKNOWN'::text) AND 
 ((combined_owner_address)::text <> 'UNKNOWN'::text) AND 
 ((p1.combined_owner_address)::text = 
 (combined_owner_address)::text))) AND st_dwithin(p1.shape, shape, 
 '90'::double precision))
            Rows Removed by Filter: 0
            Heap Blocks: exact=230342
            ->  BitmapAnd  (cost=4.91..4.91 rows=1 width=0) (actual 
 time=0.110..0.110 rows=0 loops=115677)
                  ->  Bitmap Index Scan on geom_idx  
 (cost=0.00..1.60 rows=12 width=0) (actual time=0.064..0.064 
 rows=32 loops=115677)
                        Index Cond: (shape && st_expand(p1.shape, 
 '90'::double precision))
                  ->  BitmapOr  (cost=3.07..3.07 rows=4 width=0) 
 (actual time=0.040..0.040 rows=0 loops=115677)
                        ->  Bitmap Index Scan on 
  combined_owner_name_idx  (cost=0.00..1.53 rows=2 width=0) (actual 
 time=0.023..0.023 rows=66 loops=115677)
                              Index Cond: 
((combined_owner_name)::text = (p1.combined_owner_name)::text)
                        ->  Bitmap Index Scan on 
combined_owner_address_idx  (cost=0.00..1.53 rows=2 width=0) 
(actual time=0.016..0.016 rows=40 loops=115677)
                              Index Cond: 
 ((combined_owner_address)::text = 
 (p1.combined_owner_address)::text)
 Planning Time: 0.378 ms
 Execution Time: 22301.460 ms