pingcap / pingcap/tiflash

cast as binary does not behave correctly when data is NaN

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#3,443 2 comments 0 reactions 0 assignees View on GitHub

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affects-6.0 affects-6.1 component/compute component/expression severity/moderate type/bug
Dominant language
C++
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Forks
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Avg merge
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Merged PRs (30d)
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Description

mysql> select /*+ READ_FROM_STORAGE(TIflash[t]) */ * from t where binary(c)='NaN';

+-------+
|   c   |
+-------+
|  NaN  |
+-------+
1 row in set (0.00 sec)

mysql> select /*+ READ_FROM_STORAGE(tikv[t]) */ * from t where binary(c)='NaN';
Empty set (0.01 sec)

v4.0.9

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  3. Fork the repository and make your change on a branch.
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Research direction

Reproduce the two queries from the issue on TiFlash and TiKV using the reported v4.0.9 behavior, focusing on the binary cast of NaN. Trace the relevant cast and comparison handling in the engine, then verify that both storage paths return consistent, correct results for the query.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
databases
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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