animovscw commented on PR #12932:
URL: https://github.com/apache/ignite/pull/12932#issuecomment-4141970682

   > locally i got :
   > 
   > ```
   > with PR:
   > Benchmark                 (engine)   Mode  Cnt    Score    Error  Units
   > JmhSqlJoinBenchmark.test        H2  thrpt    5  152.319 ± 43.203  ops/s
   > 
   > without PR:
   > Benchmark                 (engine)   Mode  Cnt    Score     Error  Units
   > JmhSqlJoinBenchmark.test        H2  thrpt    5  374.269 ±  43.047  ops/s
   > ```
   
   Thanks for measuring and for pointing out the drawdown.
   I rechecked the changes with local runs and came to the conclusion that 
there is a problem. 
   It seems that in some scenarios with a `LEFT JOIN` + subquery with 
`DISTINCT`, the consistency of alias may be violated when rewriting the AST: 
the `ON` condition continues to refer to the alias of the left branch, but the 
corresponding alias source is no longer present in the final SQL map.
   This is confirmed by an error during the JMH run: `Column "P__Z1.DEPID" not 
found`.
   
   During a load test with a complex request form (several `LEFT JOINS`), a 
crash occurs at the execution stage with the error of missing an alias.


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