I try to merge two tables in snowflake with:

```
On CONCAT(tab1.column1, tab1.column2) = CONCAT(tab1.column1, tab1.column2)

```

The problem here is that there are duplicates. that means rows where column1 and column2 in table2 are identical. the only difference is the column timestamp. Therefore i would like to have two options: either i ignore the duplicate and take only one row (with the biggest timestamp), or distinguish again based on the timestamp. the second would be nicer

But I have no clue how to do it

Example:

```
Table1:

Col1 Col2 Col3 Timestamp
24    10    3  05.05.2022
34    19    2  04.05.2022
24    10    4  06.05.2022

Table2:

Col1 Col2 Col3 
24    10    Null  
34    19    Null  

```

What I want to do:

```
MERGE INTO table1 AS dest USING
(SELECT * FROM table2) AS src
ON CONCAT(dest.col1, dest.col2) = CONCAT(src.col1, src.col2)
WHEN MATCHED THEN UPDATE
SET dest.col3 = src.col3

```