release-21.1: sql: stop mutating AST in AlterPrimaryKey #61792
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The code in cockroachdb#61345 added a test that, under stress, nicely revealed a bug. The bug is that we're mutating the AST in place and then, on retries, we hit an error. The fix is to not mutate the AST. I wish I had a more comprehensive testing strategy to ensure this didn't happen. On some level, we could clone the AST when passing it to various DDL plan node constructors. That's very defensive but also probably fine. Another thing that would be cool would be to just assert that after planning the AST did not change. Touches cockroachdb#60824. Release note: None
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fqazi
approved these changes
Mar 10, 2021
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Reviewed 5 of 5 files at r1.
Reviewable status:complete! 0 of 0 LGTMs obtained (waiting on @ajwerner)
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Backport 1/1 commits from #61784.
/cc @cockroachdb/release
The code in #61345 added a test that, under stress, nicely revealed a bug.
The bug is that we're mutating the AST in place and then, on retries, we hit
an error. The fix is to not mutate the AST.
I wish I had a more comprehensive testing strategy to ensure this didn't
happen. On some level, we could clone the AST when passing it to various DDL
plan node constructors. That's very defensive but also probably fine. Another
thing that would be cool would be to just assert that after planning the AST
did not change.
Touches #60824.
Release note: None