> ## Documentation Index
> Fetch the complete documentation index at: https://docs.allium.so/llms.txt
> Use this file to discover all available pages before exploring further.

# Order Books

> Flattened order book updates with bid and ask levels.

The `lighter_robinhood.dex.order_books` table contains flattened order book updates with bid and ask levels.

## Table Columns

| Column Name         | Data Type          | Description                                             |
| ------------------- | ------------------ | ------------------------------------------------------- |
| `timestamp`         | `TIMESTAMP_NTZ(9)` | UTC timestamp of the order book update.                 |
| `market_id`         | `NUMBER(38,0)`     | Lighter market ID.                                      |
| `symbol`            | `VARCHAR`          | Market symbol (e.g., BTC, ETH/USDG).                    |
| `market_type`       | `VARCHAR`          | 'perpetuals' or 'spot'.                                 |
| `base_symbol`       | `VARCHAR`          | Base asset symbol.                                      |
| `quote_symbol`      | `VARCHAR`          | Quote asset symbol.                                     |
| `collateral_symbol` | `VARCHAR`          | Collateral asset symbol for perpetuals. NULL for spots. |
| `base_l1_address`   | `VARCHAR`          | L1 contract address of the base asset, when applicable. |
| `side`              | `VARCHAR`          | 'ask' or 'bid'.                                         |
| `level`             | `NUMBER(38,0)`     | 0-based index within the ask or bid array.              |
| `price`             | `FLOAT`            | Price at this level in quote asset units.               |
| `size`              | `FLOAT`            | Size at this level in base asset units.                 |
| `usd_amount`        | `FLOAT`            | Dollar value at this level.                             |
| `nonce`             | `NUMBER(38,0)`     | Global sequence number at update time.                  |
| `begin_nonce`       | `NUMBER(38,0)`     | Sequence number at the start of the batch.              |
| `book_offset`       | `NUMBER(38,0)`     | Per-market incrementing version counter.                |
| `_created_at`       | `TIMESTAMP_NTZ(9)` | Timestamp when the row was first recorded.              |
| `_updated_at`       | `TIMESTAMP_NTZ(9)` | Timestamp when the row was last updated.                |

### Sample Query

```sql theme={null}
SELECT
    timestamp,
    symbol,
    side,
    level,
    price,
    size
FROM lighter_robinhood.dex.order_books
WHERE timestamp >= CURRENT_DATE
  AND symbol = 'BTC'
ORDER BY timestamp DESC, side, level
LIMIT 100;
```