ShashidharM0118 opened a new pull request, #19073:
URL: https://github.com/apache/datafusion/pull/19073

   ## Which issue does this PR close?
   
   - Closes **#18595**
   
   
   ## Rationale for this change
   
   Aggregate planning was repartitioning **tiny datasets**, leading to 
**unnecessary cost** for lightweight queries and occasionally causing **empty 
results** in TPCH-style tests.
   
   The planner now uses statistics to **keep small inputs in single-partition 
mode** when there aren't enough rows to benefit from the overhead of 
repartitioning, thus avoiding this performance drain.
   
   
   ## What changes are included in this PR?
   
   * Added the function `has_sufficient_rows_for_repartition(...)` in 
`datafusion/core/src/physical_planner.rs`.
   * Wired this check into the aggregate planning branch to only build 
`AggregateMode::FinalPartitioned` when $num\_rows \geq batch\_size$.
   * Extended planner coverage with tests (e.g., 
`hash_agg_small_dataset_single_mode`) and dataframe insta snapshots to assert 
the new single-mode plan and its explain output.
   * Regenerated all affected SQL logic suites (e.g., aggregate, group\_by, 
tpch) to reflect the planning change.
   * Marked an encrypted parquet test query as `rowsort` 
   
   
   ## Are these changes tested?
   
   **Yes.** 
   
   ## Are there any user-facing changes?
   
   **Yes.** 


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