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SELECT 8
| col_a | col_b |
|---|---|
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 2 | 1 |
| 2 | 2 |
| 2 | 3 |
| 3 | 1 |
| 3 | 2 |
SELECT 8
| array_agg | col_b |
|---|---|
| {3} | {1,2} |
| {1,2} | {1,2,3} |
SELECT 2
SELECT 8
| col_a | col_b |
|---|---|
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 2 | 1 |
| 2 | 2 |
| 2 | 3 |
| 3 | 1 |
| 3 | 2 |
SELECT 8
| array_agg | col_b |
|---|---|
| {3} | {1,2} |
| {1,2} | {1,2,3} |
SELECT 2