simplify

Author: joshua-spacetime

crates/vm/src/expr.rs

@@ -466,7 +466,7 @@ impl IndexJoin {
         // For the same reason the compiler also ensures this unwrap is safe.
         let probe_column = self.probe_side.source.head().column(&self.probe_field).unwrap().col_id;
         match self.index_side {
-            Table::MemTable(delta) if self.return_index_rows => {
+            Table::MemTable(delta) => {
                 let index_field = field(&delta, &self.index_col);
 
                 // Merge all selections from the original probe side into a single predicate.
@@ -480,25 +480,7 @@ impl IndexJoin {
                         }
                     })
                 });
-                IndexJoin {
-                    // The new probe side consists of the updated rows.
-                    probe_side: delta.into(),
-                    // The new probe field is the previous index field.
-                    probe_field: index_field,
-                    // The original probe table is now the table that is being probed.
-                    index_side: self.probe_side.source.into(),
-                    // Any selections from the original probe side are pulled above the index lookup.
-                    index_select: predicate,
-                    // The new index field is the previous probe field.
-                    index_col: probe_column,
-                    // Because we have swapped the original index and probe sides of the join,
-                    // the new index join needs to return rows from the probe side instead of the index side.
-                    return_index_rows: false,
-                }
-            }
-            Table::MemTable(delta) => {
-                let index_field = field(&delta, &self.index_col);
-
+                // Push any selections on the index side to the probe side.
                 let probe_side = if let Some(predicate) = self.index_select {
                     QueryExpr {
                         source: delta.into(),
@@ -515,13 +497,13 @@ impl IndexJoin {
                     probe_field: index_field,
                     // The original probe table is now the table that is being probed.
                     index_side: self.probe_side.source.into(),
-                    // Any selections from the index probe side are pushed to the probe side.
-                    index_select: None,
+                    // Any selections from the original probe side are pulled above the index lookup.
+                    index_select: predicate,
                     // The new index field is the previous probe field.
                     index_col: probe_column,
                     // Because we have swapped the original index and probe sides of the join,
-                    // the new index join needs to return rows from the index side instead of the probe side.
-                    return_index_rows: true,
+                    // the new index join needs to return rows from the opposite side.
+                    return_index_rows: !self.return_index_rows,
                 }
             }
             Table::DbTable(_) => self,