Do not count DELETEs occuring in an UPDATE stmt as separate changes

core/translate/analyze.rs

@@ -97,6 +97,7 @@ pub fn translate_analyze(
         program.emit_insn(Insn::Delete {
             cursor_id,
             table_name: "sqlite_stat1".to_string(),
+            is_part_of_update: false,
         });
         program.emit_insn(Insn::Next {
             cursor_id,

core/translate/emitter.rs

@@ -859,6 +859,7 @@ fn emit_delete_insns(
         program.emit_insn(Insn::Delete {
             cursor_id: main_table_cursor_id,
             table_name: table_name.to_string(),
+            is_part_of_update: false,
         });
 
         if let Some(index) = iteration_index {
@@ -867,6 +868,7 @@ fn emit_delete_insns(
             program.emit_insn(Insn::Delete {
                 cursor_id: iteration_index_cursor,
                 table_name: index.name.clone(),
+                is_part_of_update: false,
             });
         }
     }
@@ -1690,6 +1692,7 @@ fn emit_update_insns(
             program.emit_insn(Insn::Delete {
                 cursor_id: target_table_cursor_id,
                 table_name: table_name.to_string(),
+                is_part_of_update: true,
             });
         }
 

core/translate/index.rs

@@ -595,6 +595,7 @@ pub fn translate_drop_index(
     program.emit_insn(Insn::Delete {
         cursor_id: sqlite_schema_cursor_id,
         table_name: "sqlite_schema".to_string(),
+        is_part_of_update: false,
     });
 
     program.resolve_label(next_label, program.offset());

core/translate/schema.rs

@@ -745,6 +745,7 @@ pub fn translate_drop_table(
     program.emit_insn(Insn::Delete {
         cursor_id: sqlite_schema_cursor_id_0,
         table_name: SQLITE_TABLEID.to_string(),
+        is_part_of_update: false,
     });
 
     program.resolve_label(next_label, program.offset());
@@ -945,6 +946,7 @@ pub fn translate_drop_table(
         program.emit_insn(Insn::Delete {
             cursor_id: sqlite_schema_cursor_id_1,
             table_name: SQLITE_TABLEID.to_string(),
+            is_part_of_update: false,
         });
         program.emit_insn(Insn::Insert {
             cursor: sqlite_schema_cursor_id_1,
@@ -1005,6 +1007,7 @@ pub fn translate_drop_table(
         program.emit_insn(Insn::Delete {
             cursor_id: seq_cursor_id,
             table_name: "sqlite_sequence".to_string(),
+            is_part_of_update: false,
         });
 
         program.resolve_label(continue_loop_label, program.offset());

core/translate/upsert.rs

@@ -726,6 +726,7 @@ pub fn emit_upsert(
         program.emit_insn(Insn::Delete {
             cursor_id: tbl_cursor_id,
             table_name: table.get_name().to_string(),
+            is_part_of_update: true,
         });
         program.emit_insn(Insn::Insert {
             cursor: tbl_cursor_id,

core/translate/view.rs

@@ -113,6 +113,7 @@ pub fn translate_create_materialized_view(
     program.emit_insn(Insn::Delete {
         cursor_id: view_cursor_id,
         table_name: normalized_view_name.clone(),
+        is_part_of_update: false,
     });
     program.emit_insn(Insn::Next {
         cursor_id: view_cursor_id,
@@ -409,6 +410,7 @@ pub fn translate_drop_view(
     program.emit_insn(Insn::Delete {
         cursor_id: sqlite_schema_cursor_id,
         table_name: "sqlite_schema".to_string(),
+        is_part_of_update: false,
     });
 
     program.resolve_label(skip_delete_label, program.offset());

core/vdbe/execute.rs

@@ -6046,7 +6046,8 @@ pub fn op_delete(
     load_insn!(
         Delete {
             cursor_id,
-            table_name
+            table_name,
+            is_part_of_update,
         },
         insn
     );
@@ -6131,9 +6132,13 @@ pub fn op_delete(
     }
 
     state.op_delete_state.sub_state = OpDeleteSubState::MaybeCaptureRecord;
-    program
+    if !is_part_of_update {
-        .n_change
+        // DELETEs do not count towards the total changes if they are part of an UPDATE statement,
-        .fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+        // i.e. the DELETE and subsequent INSERT of a row are the same "change".
+        program
+            .n_change
+            .fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+    }
     state.pc += 1;
     Ok(InsnFunctionStepResult::Step)
 }

core/vdbe/explain.rs

@@ -1141,7 +1141,7 @@ pub fn insn_to_row(
                 flag.0 as u16,
                 format!("intkey=r[{key_reg}] data=r[{record_reg}]"),
             ),
-            Insn::Delete { cursor_id, table_name } => (
+            Insn::Delete { cursor_id, table_name, .. } => (
                 "Delete",
                 *cursor_id as i32,
                 0,

core/vdbe/insn.rs

@@ -791,6 +791,8 @@ pub enum Insn {
     Delete {
         cursor_id: CursorID,
         table_name: String,
+        /// Whether the DELETE is part of an UPDATE statement. If so, it doesn't count towards the change counter.
+        is_part_of_update: bool,
     },
 
     /// If P5 is not zero, then raise an SQLITE_CORRUPT_INDEX error if no matching index entry