graph/db: use batch fetching for DeleteChannelEdges

diff --git a/graph/db/sql_store.go b/graph/db/sql_store.go
index d6d7c54..cd960b1 100644
--- a/graph/db/sql_store.go
+++ b/graph/db/sql_store.go
@@ -1615,11 +1615,12 @@ func (s *SQLStore) DeleteChannelEdges(strictZombiePruning, markZombie bool,
 	}
 
 	var (
-		ctx     = context.TODO()
-		deleted []*models.ChannelEdgeInfo
+		ctx   = context.TODO()
+		edges []*models.ChannelEdgeInfo
 	)
 	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
-		chanIDsToDelete := make([]int64, 0, len(chanIDs))
+		// First, collect all channel rows.
+		var channelRows []sqlc.GetChannelsBySCIDWithPoliciesRow
 		chanCallBack := func(ctx context.Context,
 			row sqlc.GetChannelsBySCIDWithPoliciesRow) error {
 
@@ -1628,65 +1629,7 @@ func (s *SQLStore) DeleteChannelEdges(strictZombiePruning, markZombie bool,
 			scid := byteOrder.Uint64(row.GraphChannel.Scid)
 			delete(chanLookup, scid)
 
-			node1, node2, err := buildNodeVertices(
-				row.GraphNode.PubKey, row.GraphNode_2.PubKey,
-			)
-			if err != nil {
-				return err
-			}
-
-			info, err := getAndBuildEdgeInfo(
-				ctx, db, s.cfg.ChainHash, row.GraphChannel,
-				node1, node2,
-			)
-			if err != nil {
-				return err
-			}
-
-			deleted = append(deleted, info)
-			chanIDsToDelete = append(
-				chanIDsToDelete, row.GraphChannel.ID,
-			)
-
-			if !markZombie {
-				return nil
-			}
-
-			nodeKey1, nodeKey2 := info.NodeKey1Bytes,
-				info.NodeKey2Bytes
-			if strictZombiePruning {
-				var e1UpdateTime, e2UpdateTime *time.Time
-				if row.Policy1LastUpdate.Valid {
-					e1Time := time.Unix(
-						row.Policy1LastUpdate.Int64, 0,
-					)
-					e1UpdateTime = &e1Time
-				}
-				if row.Policy2LastUpdate.Valid {
-					e2Time := time.Unix(
-						row.Policy2LastUpdate.Int64, 0,
-					)
-					e2UpdateTime = &e2Time
-				}
-
-				nodeKey1, nodeKey2 = makeZombiePubkeys(
-					info.NodeKey1Bytes, info.NodeKey2Bytes,
-					e1UpdateTime, e2UpdateTime,
-				)
-			}
-
-			err = db.UpsertZombieChannel(
-				ctx, sqlc.UpsertZombieChannelParams{
-					Version:  int16(ProtocolV1),
-					Scid:     channelIDToBytes(scid),
-					NodeKey1: nodeKey1[:],
-					NodeKey2: nodeKey2[:],
-				},
-			)
-			if err != nil {
-				return fmt.Errorf("unable to mark channel as "+
-					"zombie: %w", err)
-			}
+			channelRows = append(channelRows, row)
 
 			return nil
 		}
@@ -1702,9 +1645,37 @@ func (s *SQLStore) DeleteChannelEdges(strictZombiePruning, markZombie bool,
 			return ErrEdgeNotFound
 		}
 
+		if len(channelRows) == 0 {
+			return nil
+		}
+
+		// Batch build all channel edges.
+		var chanIDsToDelete []int64
+		edges, chanIDsToDelete, err = batchBuildChannelInfo(
+			ctx, s.cfg, db, channelRows,
+		)
+		if err != nil {
+			return err
+		}
+
+		if markZombie {
+			for i, row := range channelRows {
+				scid := byteOrder.Uint64(row.GraphChannel.Scid)
+
+				err := handleZombieMarking(
+					ctx, db, row, edges[i],
+					strictZombiePruning, scid,
+				)
+				if err != nil {
+					return fmt.Errorf("unable to mark "+
+						"channel as zombie: %w", err)
+				}
+			}
+		}
+
 		return s.deleteChannels(ctx, db, chanIDsToDelete)
 	}, func() {
-		deleted = nil
+		edges = nil
 
 		// Re-fill the lookup map.
 		for _, chanID := range chanIDs {
@@ -1721,7 +1692,7 @@ func (s *SQLStore) DeleteChannelEdges(strictZombiePruning, markZombie bool,
 		s.chanCache.remove(chanID)
 	}
 
-	return deleted, nil
+	return edges, nil
 }
 
 // FetchChannelEdgesByID attempts to lookup the two directed edges for the
@@ -5406,3 +5377,90 @@ func batchBuildChannelEdges[T sqlc.ChannelAndNodes](ctx context.Context,
 
 	return edges, nil
 }
+
+// batchBuildChannelInfo builds a slice of models.ChannelEdgeInfo
+// instances from the provided rows using batch loading for channel data.
+func batchBuildChannelInfo[T sqlc.ChannelAndNodeIDs](ctx context.Context,
+	cfg *SQLStoreConfig, db SQLQueries, rows []T) (
+	[]*models.ChannelEdgeInfo, []int64, error) {
+
+	if len(rows) == 0 {
+		return nil, nil, nil
+	}
+
+	// Collect all the channel IDs needed for batch loading.
+	channelIDs := make([]int64, len(rows))
+	for i, row := range rows {
+		channelIDs[i] = row.Channel().ID
+	}
+
+	// Batch load the channel data.
+	channelBatchData, err := batchLoadChannelData(
+		ctx, cfg.QueryCfg, db, channelIDs, nil,
+	)
+	if err != nil {
+		return nil, nil, fmt.Errorf("unable to batch load channel "+
+			"data: %w", err)
+	}
+
+	// Build all channel edges using batch data.
+	edges := make([]*models.ChannelEdgeInfo, 0, len(rows))
+	for _, row := range rows {
+		node1, node2, err := buildNodeVertices(
+			row.Node1Pub(), row.Node2Pub(),
+		)
+		if err != nil {
+			return nil, nil, err
+		}
+
+		// Build channel info using batch data
+		info, err := buildEdgeInfoWithBatchData(
+			cfg.ChainHash, row.Channel(), node1, node2,
+			channelBatchData,
+		)
+		if err != nil {
+			return nil, nil, err
+		}
+
+		edges = append(edges, info)
+	}
+
+	return edges, channelIDs, nil
+}
+
+// handleZombieMarking is a helper function that handles the logic of
+// marking a channel as a zombie in the database. It takes into account whether
+// we are in strict zombie pruning mode, and adjusts the node public keys
+// accordingly based on the last update timestamps of the channel policies.
+func handleZombieMarking(ctx context.Context, db SQLQueries,
+	row sqlc.GetChannelsBySCIDWithPoliciesRow, info *models.ChannelEdgeInfo,
+	strictZombiePruning bool, scid uint64) error {
+
+	nodeKey1, nodeKey2 := info.NodeKey1Bytes, info.NodeKey2Bytes
+
+	if strictZombiePruning {
+		var e1UpdateTime, e2UpdateTime *time.Time
+		if row.Policy1LastUpdate.Valid {
+			e1Time := time.Unix(row.Policy1LastUpdate.Int64, 0)
+			e1UpdateTime = &e1Time
+		}
+		if row.Policy2LastUpdate.Valid {
+			e2Time := time.Unix(row.Policy2LastUpdate.Int64, 0)
+			e2UpdateTime = &e2Time
+		}
+
+		nodeKey1, nodeKey2 = makeZombiePubkeys(
+			info.NodeKey1Bytes, info.NodeKey2Bytes, e1UpdateTime,
+			e2UpdateTime,
+		)
+	}
+
+	return db.UpsertZombieChannel(
+		ctx, sqlc.UpsertZombieChannelParams{
+			Version:  int16(ProtocolV1),
+			Scid:     channelIDToBytes(scid),
+			NodeKey1: nodeKey1[:],
+			NodeKey2: nodeKey2[:],
+		},
+	)
+}
diff --git a/sqldb/sqlc/db_custom.go b/sqldb/sqlc/db_custom.go
index 64440a2..8230028 100644
--- a/sqldb/sqlc/db_custom.go
+++ b/sqldb/sqlc/db_custom.go
@@ -71,3 +71,37 @@ func (r GetChannelsByPolicyLastUpdateRangeRow) Node1() GraphNode {
 func (r GetChannelsByPolicyLastUpdateRangeRow) Node2() GraphNode {
 	return r.GraphNode_2
 }
+
+// ChannelAndNodeIDs is an interface that provides access to a channel and its
+// two node public keys.
+type ChannelAndNodeIDs interface {
+	// Channel returns the GraphChannel associated with this interface.
+	Channel() GraphChannel
+
+	// Node1Pub returns the public key of the first node as a byte slice.
+	Node1Pub() []byte
+
+	// Node2Pub returns the public key of the second node as a byte slice.
+	Node2Pub() []byte
+}
+
+// Channel returns the GraphChannel associated with this interface.
+//
+// NOTE: This method is part of the ChannelAndNodeIDs interface.
+func (r GetChannelsBySCIDWithPoliciesRow) Channel() GraphChannel {
+	return r.GraphChannel
+}
+
+// Node1Pub returns the public key of the first node as a byte slice.
+//
+// NOTE: This method is part of the ChannelAndNodeIDs interface.
+func (r GetChannelsBySCIDWithPoliciesRow) Node1Pub() []byte {
+	return r.GraphNode.PubKey
+}
+
+// Node2Pub returns the public key of the second node as a byte slice.
+//
+// NOTE: This method is part of the ChannelAndNodeIDs interface.
+func (r GetChannelsBySCIDWithPoliciesRow) Node2Pub() []byte {
+	return r.GraphNode_2.PubKey
+}