Make live route writes cheaper so the prefix handler keeps up (closes #96)

The live route tables lose their random UUID key; the row id the
prefix-length sample draws is declared as the integer key. The prefix
tables are keyed by prefix and keep only first_seen; a batch inserts only
prefixes not stored yet. A route update sets only the columns that
change. Each kept index names the queries using it. Every write goes
through one connection kept for writing, with a 1 GiB page cache; reading
connections get 16 MiB, heap limits rise to 1.5 and 2 GiB (README
"Memory"). Batch writes go in key order. A benchmark run by hand writes
250,000 updates on 5 million routes faster than the feed's 10,000 a
second; a live run follows.

Model: opus-5-5

internal/routewatch/app_integration_internal_test.go

@@ -18,7 +18,6 @@ import (
 	"git.eeqj.de/sneak/routewatch/internal/ristypes"
 	"git.eeqj.de/sneak/routewatch/internal/server"
 	"git.eeqj.de/sneak/routewatch/internal/streamer"
-	"github.com/google/uuid"
 )
 
 // mockStore is a mock implementation of database.Store for testing
@@ -83,9 +82,7 @@ func (m *mockStore) UpdatePrefixesBatch(prefixes map[string]time.Time) error {
 	defer m.mu.Unlock()
 
 	for prefix, timestamp := range prefixes {
-		if p, exists := m.Prefixes[prefix]; exists {
-			p.LastSeen = timestamp
-		} else {
+		if _, exists := m.Prefixes[prefix]; !exists {
 			const (
 				ipVersionV4 = 4
 				ipVersionV6 = 6
@@ -97,11 +94,9 @@ func (m *mockStore) UpdatePrefixesBatch(prefixes map[string]time.Time) error {
 			}
 
 			m.Prefixes[prefix] = &database.Prefix{
-				ID:        uuid.New(),
 				Prefix:    prefix,
 				IPVersion: ipVersion,
 				FirstSeen: timestamp,
-				LastSeen:  timestamp,
 			}
 		}
 	}
@@ -117,8 +112,6 @@ func (m *mockStore) GetOrCreatePrefix(
 	defer m.mu.Unlock()
 
 	if p, exists := m.Prefixes[prefix]; exists {
-		p.LastSeen = timestamp
-
 		return p, nil
 	}
 
@@ -133,11 +126,9 @@ func (m *mockStore) GetOrCreatePrefix(
 	}
 
 	p := &database.Prefix{
-		ID:        uuid.New(),
 		Prefix:    prefix,
 		IPVersion: ipVersion,
 		FirstSeen: timestamp,
-		LastSeen:  timestamp,
 	}
 	m.Prefixes[prefix] = p
 	m.PrefixCount++
@@ -370,11 +361,9 @@ func (m *mockStore) UpsertLiveRouteBatch(routes []*database.LiveRoute) error {
 		// Track prefix
 		if _, exists := m.Prefixes[route.Prefix]; !exists {
 			m.Prefixes[route.Prefix] = &database.Prefix{
-				ID:        uuid.New(),
 				Prefix:    route.Prefix,
 				IPVersion: route.IPVersion,
 				FirstSeen: route.LastUpdated,
-				LastSeen:  route.LastUpdated,
 			}
 			m.PrefixCount++
 

internal/routewatch/prefixhandler.go

@@ -12,7 +12,6 @@ import (
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
 	"git.eeqj.de/sneak/routewatch/internal/ristypes"
-	"github.com/google/uuid"
 )
 
 const (
@@ -461,7 +460,6 @@ func (h *PrefixHandler) createLiveRoute(update prefixUpdate) *database.LiveRoute
 
 	// Create live route record
 	liveRoute := &database.LiveRoute{
-		ID:          uuid.New(),
 		Prefix:      update.prefix,
 		MaskLength:  maskLength,
 		IPVersion:   ipVersion,