Cockroach: jobs get created multiple times

[schorzz]

Describe the problem

I tried to alter a table (drop a column) and two jobs got created for a single sql statement.

To Reproduce

I tried to alter a table via Alembic AND via cockroach sql. So far this only happens when i want to drop a column. The problem is, that the statement (code or sql-cli) blocks until BOTH jobs are finished. Also, both jobs succeed even though a column can be deleted just once.

1. Create empty schema in a 5 node cockroach cluster
2. insert about 100k rows
3. add column with index
4. drop column
5. Look at UI-JOBS OR sql-cli show jobs
6. See same job two times with different job-ids

Expected behavior
A job for ALTER TABLE should be executed once, and the second job should fail.

Environment:

• CockroachDB version 2.1.4
• Docker Image 2.1.4
• cockroach sql, SQLAlchemy, Alembic

[schorzz]

Apparently, cockroach deletes indices implicitly if you drop the column. Although the naming of the jobs are a little bit confusing.

[awoods187]

@schorzz I went ahead and opened this issue (https://github.com/cockroachdb/cockroach/issues/35051) to improve upon this so that other users won't be similarly confused. Thank you for sharing your feedback!