# Prices

Each historical prices dataset is structured with a top level table that contains aggregated prices across all supported exchanges. Each supported exchange then has its own subtable where prices from just that exchange are available. 

Prices are available in High-Low-Open-Close (HLOC) format.

#### Top level token historical token prices tables

| Table Name   | Description                                                                 |
| ------------ | --------------------------------------------------------------------------- |
| `prices.eth` | HLOC values for ETH at 1 minute granularity aggregated across all exchanges |
| `prices.btc` | HLOC values for BTC at 1 minute granularity aggregated across all exchanges |
| `prices.ltc` | HLOC values for LTC at 1 minute granularity aggregated across all exchanges |

The table list is also available as a SQL query using `show tables`. For example:

```sql
SHOW TABLES IN prices
```

The columns and their schema available for each table can be viewed with the `describe <table>` command. For example:

```sql
/* Show the columns available */
DESCRIBE prices.eth;
DESCRIBE prices.btc;
DESCRIBE prices.ltc;
```

#### Improving query performance - indexed columns

Query performance can be significantly improved by adding `WHERE` clauses to your query on specific indexed columns.

| Table Name   | Indexed Columns |
| ------------ | --------------- |
| `prices.eth` | `timestamp`     |
| `prices.btc` | `timestamp`     |
| `prices.ltc` | `timestamp`     |