You want to perform the following operations on a table using PostgreSQL:
1. Select index_id and make distinct query on the column_name column.
2. Return the highest index_id of each distinct column.
Which of these queries can help you do this?
Options
1.SELECT UNIQUE ON (column_name) index_id
FROM table_name
group by column_name, index_id desc;
2.SELECT UNIQUE ON (column_name) index_id
FROM table_name
order by column_name, index_id desc;
3.SELECT DISTINCT ON (column_name) index_id
FROM table_name
group by column_name, index_id desc;
4.SELECT DISTINCT ON (column_name) index_id
FROM table_name
order by column_name, index_id desc;
