DNS server (add NS record)

dns/migrations/003_add_ns_records.sql

@@ -0,0 +1,10 @@
+-- Re-add NS record support and extend record types
+ALTER TABLE dns_records DROP CONSTRAINT IF EXISTS dns_records_record_type_check;
+ALTER TABLE dns_records ADD CONSTRAINT dns_records_record_type_check 
+    CHECK (record_type IN ('A', 'AAAA', 'CNAME', 'TXT', 'NS', 'MX'));
+
+-- Add index for efficient NS record lookups during delegation
+CREATE INDEX IF NOT EXISTS idx_dns_records_ns_lookup ON dns_records(record_type, name) WHERE record_type = 'NS';
+
+-- Add index for subdomain resolution optimization
+CREATE INDEX IF NOT EXISTS idx_dns_records_subdomain_lookup ON dns_records(domain_id, name, record_type);