diff --git a/routes/operations.js b/routes/operations.js
index 1b4385c..2c97cbb 100644
--- a/routes/operations.js
+++ b/routes/operations.js
@@ -32,6 +32,22 @@ module.exports = function(pool) {
         return clean;
     }
 
+    // How a multi-slice request is split into statements.
+    //
+    //   'each'    — one statement per slice, so every slice reaches its target on
+    //               its own and gets its own log entry
+    //   'prorate' — a single statement over all of them, letting the SQL's
+    //               sum() OVER () distribute across the whole pool
+    //
+    // Only scale has a target to prorate towards; recode and clone rewrite rows
+    // rather than distribute an amount, so for them this only decides whether the
+    // work lands as one log entry or several.
+    function sliceUnits(slices, ctx, applyMode) {
+        return applyMode === 'each'
+            ? slices.map(sl => ({ slices: [sl], where: buildWhere(sl, ctx.filterCols) }))
+            : [{ slices, where: buildWhereAny(slices, ctx.filterCols) }];
+    }
+
     // A slice is only meaningful if at least one of its keys is a filterable
     // column. buildWhere silently drops unknown keys, so {"typo": "x"} would
     // otherwise reduce to TRUE and apply the operation to the whole version.
@@ -572,9 +588,7 @@ module.exports = function(pool) {
             // sum() OVER () distribute the increment across the whole pool.
             // 'each' runs the same statement once per slice, so every slice
             // reaches the target on its own and gets its own log entry.
-            const units = applyMode === 'each'
-                ? slices.map(sl => ({ slices: [sl], where: buildWhere(sl, ctx.filterCols) }))
-                : [{ slices, where: buildWhereAny(slices, ctx.filterCols) }];
+            const units = sliceUnits(slices, ctx, applyMode);
 
             const client = await pool.connect();
             let committed = false;
@@ -656,7 +670,7 @@ module.exports = function(pool) {
 
             const excludeClause = buildExcludeClause(ctx.version.exclude_iters);
             const setClause     = buildSetClause(ctx.dimCols, set);
-            const units         = sliceUnits(slices, ctx, apply_mode);
+            const units         = sliceUnits(slices, ctx, apply_mode === 'each' ? 'each' : 'prorate');
 
             const client = await pool.connect();
             let committed = false;
@@ -712,7 +726,7 @@ module.exports = function(pool) {
             const scaleFactor   = (scale != null) ? parseFloat(scale) : 1.0;
             const excludeClause = buildExcludeClause(ctx.version.exclude_iters);
             const setClause     = buildSetClause(ctx.dimCols, set);
-            const units         = sliceUnits(slices, ctx, apply_mode);
+            const units         = sliceUnits(slices, ctx, apply_mode === 'each' ? 'each' : 'prorate');
 
             const client = await pool.connect();
             let committed = false;