sgrebnov opened a new pull request, #13599:
URL: https://github.com/apache/datafusion/pull/13599

   ## Which issue does this PR close?
   
   Follow-up item for [Support unparsing plans after applying the 
`optimize_projections` rule 
PR](https://github.com/apache/datafusion/pull/13267), focusing on the unparsing 
enhancement to support the described scenario.
   
   With the `optimize_projections` optimization, columns are pushed down to the 
`TableScan`, resulting in both `Projection` and `TableScan` nodes containing 
projection information. As a result, the generated SQL contains a duplicate 
subquery, e.g., `SELECT a, b FROM (SELECT a, b FROM my_table).`
   
   ## What changes are included in this PR?
   
   PR updates `unparse_table_scan_pushdown` to prevent the creation of an 
additional projection if the unparser already includes a projection (`SELECT`) 
part.
   
   ## Are these changes tested?
   
   Yes, TPC-H, TPC-DS benchmark tests, unit tests.
   
   ## Are there any user-facing changes?
   
   Improved Plan-to-SQL conversion when a TableScan with projection information 
is wrapped in a Projection.
   


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