Add schema_name to redshift query

## Overview
Add schema name option for redshift.

## Background
We can not copy logs to non-'public' schema tables because 'schema_name.table_name' syntax is not available to fetch columns query.

```sql
copy schema_name.table_name from ...  -- => OK
copy table_name from ... -- => OK(default schema is 'public')


select column_name from INFORMATION_SCHEMA.COLUMNS 
where table_name = 'schema_name.table_name from'...  -- => NG

select column_name from INFORMATION_SCHEMA.COLUMNS 
where table_schema = 'schema_name' and table_name = 'table_name from'...  -- => OK
```