Home/ Questions/Q 7910891
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-03T13:02:45+00:00

Table one: 35 million records Table two: 1,6 million records I’m executing an update

  • 0

Table one: 35 million records
Table two: 1,6 million records

I’m executing an update query in table one based upon 3 equalities. Both tables are pure data colls without any keys.

`UPDATE table1,table2
SET table1.TravelTime=table2.CongestionTime
WHERE table1.From = table2.From
AND table1.To = table2.To
AND table1.Time= table2.Time`

Yet this operation seems to be doomed to be slow. Is there a way to be creative to speed up this process?

Currently a query is running at a mere 300 updates/second suggesting it would take 33 hours to complete this query.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Both tables are pure data colls without any keys.

    I think you just said it there. You need indexes to get good performance when working with this amount of data.

    Try adding multi-column indexes:

    • (From, To, Time) for Table1.
    • (From, To, Time, CongestionTime) for Table2.

    You may also want to consider if it is appropriate to add a foreign key constraint.

    Related documentation

    • 0