skills/clickhouse-best-practices/rules/insert-format-native.md

---
title: Use Native Format for Best Insert Performance
impact: MEDIUM
impactDescription: "Native format is most efficient; JSONEachRow is expensive to parse"
tags: [insert, format, Native, performance]
---

## Use Native Format for Best Insert Performance

**Impact: MEDIUM**

Data format affects insert performance. Native format is column-oriented with minimal parsing overhead.

**Performance Ranking (fastest to slowest):**

| Format | Notes |
|--------|-------|
| **Native** | Most efficient. Column-oriented, minimal parsing. Recommended. |
| **RowBinary** | Efficient row-based alternative |
| **JSONEachRow** | Easier to use but expensive to parse |

**Example:**

```python
# Use Native format for best performance
client.execute("INSERT INTO events VALUES", data, settings={'input_format': 'Native'})
```

Reference: [Selecting an Insert Strategy](https://clickhouse.com/docs/best-practices/selecting-an-insert-strategy)