feat(asset): create incremental materialized views for asset search

- Add pg_ivm extension for incremental materialized view maintenance
- Create asset_search_view for Website model with optimized columns for full-text search
- Create endpoint_search_view for Endpoint model with matching search schema
- Add database indexes on host, url, title, status_code, and created_at columns for both views
- Enable high-performance asset search queries with automatic view maintenance

backend/apps/asset/migrations/0002_create_search_views.py

@@ -0,0 +1,104 @@
+"""
+创建资产搜索物化视图（使用 pg_ivm 增量维护）
+
+这些视图用于资产搜索功能，提供高性能的全文搜索能力。
+"""
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    """创建资产搜索所需的增量物化视图"""
+
+    dependencies = [
+        ('asset', '0001_initial'),
+    ]
+
+    operations = [
+        # 1. 确保 pg_ivm 扩展已安装
+        migrations.RunSQL(
+            sql="CREATE EXTENSION IF NOT EXISTS pg_ivm;",
+            reverse_sql="DROP EXTENSION IF EXISTS pg_ivm;",
+        ),
+        
+        # 2. 创建 Website 搜索视图
+        # 注意：pg_ivm 不支持 ArrayField，所以 tech 字段需要从原表 JOIN 获取
+        migrations.RunSQL(
+            sql="""
+                SELECT pgivm.create_immv('asset_search_view', $$
+                    SELECT 
+                        w.id,
+                        w.url,
+                        w.host,
+                        w.title,
+                        w.status_code,
+                        w.response_headers,
+                        w.response_body,
+                        w.content_type,
+                        w.content_length,
+                        w.webserver,
+                        w.location,
+                        w.vhost,
+                        w.created_at,
+                        w.target_id
+                    FROM website w
+                $$);
+            """,
+            reverse_sql="DROP TABLE IF EXISTS asset_search_view CASCADE;",
+        ),
+        
+        # 3. 创建 Endpoint 搜索视图
+        migrations.RunSQL(
+            sql="""
+                SELECT pgivm.create_immv('endpoint_search_view', $$
+                    SELECT 
+                        e.id,
+                        e.url,
+                        e.host,
+                        e.title,
+                        e.status_code,
+                        e.response_headers,
+                        e.response_body,
+                        e.content_type,
+                        e.content_length,
+                        e.webserver,
+                        e.location,
+                        e.vhost,
+                        e.created_at,
+                        e.target_id
+                    FROM endpoint e
+                $$);
+            """,
+            reverse_sql="DROP TABLE IF EXISTS endpoint_search_view CASCADE;",
+        ),
+        
+        # 4. 为搜索视图创建索引（加速查询）
+        migrations.RunSQL(
+            sql=[
+                # Website 搜索视图索引
+                "CREATE INDEX IF NOT EXISTS asset_search_view_host_idx ON asset_search_view (host);",
+                "CREATE INDEX IF NOT EXISTS asset_search_view_url_idx ON asset_search_view (url);",
+                "CREATE INDEX IF NOT EXISTS asset_search_view_title_idx ON asset_search_view (title);",
+                "CREATE INDEX IF NOT EXISTS asset_search_view_status_idx ON asset_search_view (status_code);",
+                "CREATE INDEX IF NOT EXISTS asset_search_view_created_idx ON asset_search_view (created_at DESC);",
+                # Endpoint 搜索视图索引
+                "CREATE INDEX IF NOT EXISTS endpoint_search_view_host_idx ON endpoint_search_view (host);",
+                "CREATE INDEX IF NOT EXISTS endpoint_search_view_url_idx ON endpoint_search_view (url);",
+                "CREATE INDEX IF NOT EXISTS endpoint_search_view_title_idx ON endpoint_search_view (title);",
+                "CREATE INDEX IF NOT EXISTS endpoint_search_view_status_idx ON endpoint_search_view (status_code);",
+                "CREATE INDEX IF NOT EXISTS endpoint_search_view_created_idx ON endpoint_search_view (created_at DESC);",
+            ],
+            reverse_sql=[
+                "DROP INDEX IF EXISTS asset_search_view_host_idx;",
+                "DROP INDEX IF EXISTS asset_search_view_url_idx;",
+                "DROP INDEX IF EXISTS asset_search_view_title_idx;",
+                "DROP INDEX IF EXISTS asset_search_view_status_idx;",
+                "DROP INDEX IF EXISTS asset_search_view_created_idx;",
+                "DROP INDEX IF EXISTS endpoint_search_view_host_idx;",
+                "DROP INDEX IF EXISTS endpoint_search_view_url_idx;",
+                "DROP INDEX IF EXISTS endpoint_search_view_title_idx;",
+                "DROP INDEX IF EXISTS endpoint_search_view_status_idx;",
+                "DROP INDEX IF EXISTS endpoint_search_view_created_idx;",
+            ],
+        ),
+    ]