fix(schema-compiler): Fix pre-agg matching for 'rollupJoin' / 'rollupLambda' pre-aggregations

Author: KSDaemon

packages/cubejs-schema-compiler/src/adapter/PreAggregations.ts

@@ -507,8 +507,16 @@ export class PreAggregations {
     filterDimensionsSingleValueEqual =
       allValuesEq1(filterDimensionsSingleValueEqual) ? new Set(filterDimensionsSingleValueEqual?.keys()) : null;
 
+    // Build reverse query joins map, which is used for
+    // rollupLambda and rollupJoin pre-aggs matching later
+    const joinsMap: Record<string, string> = {};
+    for (const j of query.join.joins) {
+      joinsMap[j.to] = j.from;
+    }
+
     return {
-      joinGraph: query.join,
+      joinGraphRoot: query.join.root,
+      joinsMap,
       sortedDimensions,
       sortedTimeDimensions,
       timeDimensions,
@@ -734,11 +742,33 @@ export class PreAggregations {
       if (references.rollups.length > 0) {
         // In 'rollupJoin' / 'rollupLambda' pre-aggregations fullName members will be empty, because there are
         // no connections in the joinTree between cubes from different datasources
+        // but joinGraph of the query has all the connections, necessary for serving the query,
+        // so we use this information to complete the full paths of members from the root of the query
+        // up to the pre-agg cube.
         dimsToMatch = references.dimensions;
         timeDimsToMatch = references.timeDimensions;
 
+        const buildPath = (cube: string): string[] => {
+          const path = [cube];
+          const parentMap = transformedQuery.joinsMap;
+          while (parentMap[cube]) {
+            cube = parentMap[cube];
+            path.push(cube);
+          }
+          return path.reverse();
+        };
+
         dimensionsMatch = (dimensions, doBackAlias) => {
-          const target = doBackAlias ? backAlias(dimsToMatch) : dimsToMatch;
+          let target = doBackAlias ? backAlias(dimsToMatch) : dimsToMatch;
+          target = target.map(dim => {
+            const [cube, field] = dim.split('.');
+            if (cube === transformedQuery.joinGraphRoot) {
+              return dim;
+            }
+            const path = buildPath(cube);
+            return `${path.join('.')}.${field}`;
+          });
+
           return dimensions.every(d => target.includes(d));
         };
       } else {