-
Type: Documentation
-
Resolution: Fixed
-
Priority: Major - P3
-
Affects Version/s: None
-
Component/s: None
-
3
-
BermudaTriangle- 2023-09-05, TheMoon-StorEng - 2023-09-19
Following from the WT-8003, it is not documented on how the random cursor internally chooses a random page. It would be worthwhile for our customers to understand how this works. I grabbed the process on how we grab a record from a tree from WT-8003:
- Calls __wt_random_descent, which randomly from the root page chooses a random child page until we reach a leaf page.
- If disk records are > 1000, find a visible record from page disk.
- Look to find a visible record from the insert list
- If disk records are < 200 or the leaf page is clean, try to find a visible page disk.
- Last step, clear the cursor position and compute a random record between 0 - 250 entries and perform bt_curnext and bt_curprev until we find a visible record, which can be on a different page than our original page that we descended from.
We should document the above in our documentation.
- related to
-
WT-8003 Fix frequent duplicate keys returned by random cursor in resharding test
- Closed