feat: Use IS DISTINCT FROM instead

packages/worker/postgres/upsert.spec.ts

@@ -74,11 +74,11 @@ test('upsert query', async () => {
       "raw_data" = excluded.raw_data,
       "_supaglue_unified_data" = excluded._supaglue_unified_data
     where
-      "engagement_sequences"."last_modified_at" != excluded.last_modified_at
-      AND "engagement_sequences"."_supaglue_emitted_at" != excluded._supaglue_emitted_at
-      AND "engagement_sequences"."is_deleted" != excluded.is_deleted
-      AND "engagement_sequences"."raw_data" != excluded.raw_data
-      AND "engagement_sequences"."_supaglue_unified_data" != excluded._supaglue_unified_data
+      "engagement_sequences"."last_modified_at" IS DISTINCT FROM excluded.last_modified_at
+      AND "engagement_sequences"."_supaglue_emitted_at" IS DISTINCT FROM excluded._supaglue_emitted_at
+      AND "engagement_sequences"."is_deleted" IS DISTINCT FROM excluded.is_deleted
+      AND "engagement_sequences"."raw_data" IS DISTINCT FROM excluded.raw_data
+      AND "engagement_sequences"."_supaglue_unified_data" IS DISTINCT FROM excluded._supaglue_unified_data
     "
   `)
 })

packages/worker/postgres/upsert.ts

@@ -47,7 +47,11 @@ export function dbUpsert<
       ) as PgUpdateSetSource<TTable>,
       where: sql.join(
         Object.values(upsertCols).map(
-          (c) => sql`${c} != ${sql.raw(`excluded.${c.name}`)}`,
+          // In PostgreSQL, the "IS DISTINCT FROM" operator is used to compare two values and determine
+          // if they are different, even if they are both NULL. On the other hand, the "!=" operator
+          // (also known as "not equals") compares two values and returns true if they are different,
+          // but treats NULL as an unknown value and does not consider it as different from other values.
+          (c) => sql`${c} IS DISTINCT FROM ${sql.raw(`excluded.${c.name}`)}`,
         ),
         sql` AND `,
       ),