Uses configuration from environment variables (CRDB_HOST, CRDB_USER, etc.).

Returns:
    Connection status and cluster information.

Returns:
    Disconnection status.

Returns:
    Cluster health including node count and live nodes.

Args:
    sql: SQL statement to execute.
    max_rows: Maximum rows to return (default: from config).

Returns:
    Query results with columns and rows.

Args:
    sql: SQL statement to validate.

Returns:
    Validation result with any issues found.

Args:
    sql: SQL query to explain.
    analyze: If True, actually execute to get runtime stats.

Returns:
    Query execution plan.

Args:
    include_system: Include system databases (postgres, defaultdb, etc.).

Returns:
    List of databases.

Returns:
    List of schemas.

Args:
    schema: Filter by schema name (default: all user schemas).
    include_views: Include views in results.
    include_system: Include system tables.

Returns:
    List of tables with schema, name, and type.

Args:
    table: Table name (schema.table or just table for public schema).

Returns:
    Table structure with columns, indexes, and primary key.

Args:
    table: Table name (schema.table or just table).

Returns:
    Table statistics including row count and size.

Args:
    table: Table name (schema.table or just table).

Returns:
    Foreign key information.

Args:
    table: Table name (schema.table or just table).
    id_value: Primary key value for single row lookup.
    id_column: Name of the ID column (default: 'id').
    where: WHERE clause (without 'WHERE').
    columns: List of columns to return (default: all).
    order_by: ORDER BY clause (without 'ORDER BY').
    limit: Maximum rows to return.

Returns:
    Query results.

Args:
    table: Table name (schema.table or just table).
    data: Column names and values to insert.
    returning: Columns to return from inserted row.

Returns:
    Insert result.

Args:
    table: Table name (schema.table or just table).
    id_value: Primary key value.
    data: Column names and new values.
    id_column: Name of the ID column (default: 'id').
    returning: Columns to return from updated row.

Returns:
    Update result.

Args:
    table: Table name (schema.table or just table).
    id_value: Primary key value.
    id_column: Name of the ID column (default: 'id').

Returns:
    Delete result.

Args:
    table: Table name (schema.table or just table).
    data: Column names and values.
    conflict_columns: Columns to check for conflicts (usually primary key).
    update_columns: Columns to update on conflict (default: all except conflict columns).
    returning: Columns to return.

Returns:
    Upsert result.

Args:
    database_name: Database to switch to.

Returns:
    Switch status.

Returns:
    Transaction status.

Returns:
    Commit status.

Returns:
    Rollback status.

Returns:
    List of cluster nodes with their status.

Args:
    node_id: Specific node ID (optional, returns all if not specified).

Returns:
    Node status information.

Returns:
    Region information.

Args:
    job_type: Filter by job type (BACKUP, RESTORE, IMPORT, etc.).
    status: Filter by status (running, succeeded, failed, etc.).
    limit: Maximum jobs to return.

Returns:
    List of jobs.

Args:
    active_only: Only show sessions with active queries.

Returns:
    List of sessions.

Args:
    limit: Maximum statements to return.

Returns:
    List of active statements.

Args:
    query_id: The query ID to cancel.

Returns:
    Cancellation result.

Args:
    table: Optional table to filter ranges.
    limit: Maximum ranges to return.

Returns:
    Range distribution information.

Args:
    table: Optional table to get zone config for.

Returns:
    Zone configuration.