corrected two_hop because of incorrect assumptions based on cadets dataset, change some pg configs

postgresql.conf

@@ -398,7 +398,7 @@ min_wal_size = 80MB
 # - Planner Cost Constants -
 
 #seq_page_cost = 1.0			# measured on an arbitrary scale
-#random_page_cost = 4.0			# same scale as above
+random_page_cost = 1.1			# same scale as above
 #cpu_tuple_cost = 0.01			# same scale as above
 #cpu_index_tuple_cost = 0.005		# same scale as above
 #cpu_operator_cost = 0.0025		# same scale as above
@@ -406,7 +406,7 @@ min_wal_size = 80MB
 #parallel_tuple_cost = 0.1		# same scale as above
 #min_parallel_table_scan_size = 8MB
 #min_parallel_index_scan_size = 512kB
-#effective_cache_size = 4GB
+effective_cache_size = 10GB
 
 #jit_above_cost = 100000		# perform JIT compilation if available
 					# and query more expensive than this;

query/queries.sql

@@ -87,7 +87,7 @@ PREPARE two_hop_old (INTEGER) AS
   )
   WHERE vertex <> $1;
 
-PREPARE two_hop_new (INTEGER) AS
+PREPARE two_hop (INTEGER) AS
   WITH double_edge AS NOT MATERIALIZED (
     SELECT source, destination FROM edge
     UNION ALL
@@ -97,10 +97,13 @@ PREPARE two_hop_new (INTEGER) AS
     FROM double_edge
     WHERE source = $1
   )
+  SELECT vertex
+  FROM (
     SELECT vertex
     FROM hop1
-  UNION ALL
-  SELECT DISTINCT destination
+    UNION
+    SELECT destination
     FROM double_edge
     JOIN hop1 ON vertex=source
-  WHERE destination <> $1;
+  )
+  WHERE vertex <> $1;