INSERT and primary key uniqueness violations

In many relational databases, if you try to insert a row that has already been inserted, the operation can fail because the primary key gets duplicated. Impala, however, does not fail the query. Instead, it generates a warning and continues to run the remainder of the insert statement.

If you want to replace existing rows from the table, use the UPSERT statement instead.
INSERT INTO my_first_table VALUES (99, "sarah");
UPSERT INTO my_first_table VALUES (99, "zoe");
The current value of the row is now zoe.