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

# Viewing Metadata

> Hubble publishes metadata which can help users determine which tables to query, how frequently the dataset updates, and general information about the dataset.

Hubble publishes metadata which can help users determine which tables to query, how frequently the dataset updates, and general information about the dataset.

There are two ways to access this information:

## BigQuery Explorer

When accessing Hubble from its starred link, the Explorer pane will load metadata about the `crypto-stellar.crypto_stellar` dataset.

Use the Toggle to view the contents of the Dataset. Clicking a table name will load the following:

* *Schema* - detailed information about the table schema, including column definitions and data types. Viewing the schema helps write a SQL query
* *Details* - general information about the table itself, including partitioning, clustering and table size. Viewing details helps with query optimization
* *Preview* - raw sample data from the table. The data presented is the equivalent of running a `SELECT *` statement

## INFORMATION\_SCHEMA

BigQuery supports read-only, system-defined views that provide metadata information about BigQuery objects. The views can be queried via SQL from the BigQuery UI or Client Libraries.

> [!NOTE]
>
> Queries executed against the `INFORMATION_SCHEMA` cannot be cached and **will** incur data processing charges for each run.

From the BigQuery Editor, the following query will list all tables in Hubble:

```sql SQL theme={"theme":{"light":"github-light","dark":"github-dark"}}
# List all tables in Hubble
#standardSQL
select *
from `crypto-stellar.crypto_stellar`.INFORMATION_SCHEMA.TABLES;
```

If you want details on a particular table, you can return the table schema:

```sql SQL theme={"theme":{"light":"github-light","dark":"github-dark"}}
# List all columns for the accounts table
select table_name,
  column_name,
  is_nullable,
  data_type,
  is_partitioning_column
from `crypto-stellar.crypto_stellar`.INFORMATION_SCHEMA.COLUMNS
where table_name = "accounts";
```

More on the `INFORMATION_SCHEMA` can be found [here](https://cloud.google.com/bigquery/docs/information-schema-intro).