[KUDU-3495] TServer: Unexpected result of write with old schema.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.14.0
• Fix Version/s: 1.18.0
• Component/s: tserver
• Assignee: Unassigned
• Reporter: Song Jiacheng
• Created: 25/Jul/23 10:44
• Updated: 16/Apr/24 16:10
• Resolved: 30/Aug/23 05:06

Description

For table test with two column a(primary key), b.

If I do following operations in client side:

1. openTable(test) to get a kudu table object KuduTable1 whose schema is (a, b)
2. Add a column c to table test.
3. openTable(test) to get another kudu table object KuduTable2 whose schema is (a, b, c)
4. Insert 1 row  ("d", "e", "f") using KuduTable2
5. Upsert 1 row  ("d", "g") using KuduTable1

The expected result is ("d", "g", "f") since I hope to keep the value of column c.

But the result i got was ("d", "g", NULL)

After looking through the code, I think the original reason is that the isset_bitmap is not all 0 at start.

So I initialize the bitmap like below:

After this modification, the result is as my expect.

So I wonder if it is a bug since normally a user does not want to change the column which he did not request to.