diff --git a/packages/cubejs-schema-compiler/adapter/PostgresQuery.js b/packages/cubejs-schema-compiler/adapter/PostgresQuery.js
index 3efae2bfde4b8..cee700dc347b9 100644
--- a/packages/cubejs-schema-compiler/adapter/PostgresQuery.js
+++ b/packages/cubejs-schema-compiler/adapter/PostgresQuery.js
@@ -29,6 +29,18 @@ class PostgresQuery extends BaseQuery {
   timeGroupedColumn(granularity, dimension) {
     return `date_trunc('${GRANULARITY_TO_INTERVAL[granularity]}', ${dimension})`;
   }
+
+  hllInit(sql) {
+    return `hll_add_agg(hll_hash_any(${sql}))`;
+  }
+
+  hllMerge(sql) {
+    return `hll_cardinality(hll_union_agg(${sql}))`;
+  }
+
+  countDistinctApprox(sql) {
+    return `hll_cardinality(hll_add_agg(hll_hash_any(${sql})))`;
+  }
 }
 
 module.exports = PostgresQuery;