- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
11-10-2021 06:03 PM
I have been testing OPTIMIZE a huge set of data (about 775 million rows) and getting mixed results. When I tried on a 'string' column, the query return in 2.5mins and using the same column as 'integer', using the same query, it return 9.7 seconds. Please advice.
I am using 9.1 LTS on the Azure environment.
- Labels:
-
Azure
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
11-10-2021 11:54 PM
that depends on the query, the table and what optimize you use (binning, z-order).
Delta lake by default collects statistics for the first 32 columns (which can be changed).
Building statistics for long strings is also more expensive than f.e. for integers.
Then there is also the fact that evaluating numbers is faster than strings.
What could also play is auto scaling on your cluster, or spot instances which are abandoned etc.
So, not easy to pinpoint the difference.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
11-11-2021 09:52 PM
@Werner Stinckens Thanks for your explanation.
