slow update-join query

[Neha Kansal]

Hi,

I have an update-join query which is taking longer than I would expect. The table being updated has 147 million rows and the table its joined with has 135 million rows.

Query looks like this.
update table1 a, table2 t set a.col1 = 1 where a.col2 = t.col2 and a.col3 = t.col3;

I have indexes on col2 and col3 on both the tables. I don't know how long it actually takes, I had to kill it after 9 hours. Is it expected to take this long? Any recommendations on making it faster?

Thanks,
Neha.