diff --git a/big5/README.md b/big5/README.md
index b3f540ec..cb6a92be 100755
--- a/big5/README.md
+++ b/big5/README.md
@@ -68,6 +68,7 @@ This workload allows the following parameters to be specified using `--workload-
 * `target_throughput` (default: 2): Target throughput for each query operation in requests per second, use 0 or "" for no throughput throttling.
 * `warmup_iterations` (default: 100): Number of warmup query iterations prior to actual measurements commencing.
 * `index_translog_durability` (default: "async"): Controls the transaction log flush behavior. "request" flushes after every operation to avoid data loss, while "async" batches changes for efficiency.
+* `cardinality_agg_high_field` (default: "event.id"): Use another field name for cardinality_agg_high test, previously "agent.name" was used.
 
 NOTE: If disabling `target_throughput`, know that `target_throughput:""` is snynonymous with `target_throughput:0`.
 
diff --git a/big5/operations/default.json b/big5/operations/default.json
index 82e1aa09..fa5a0b9e 100755
--- a/big5/operations/default.json
+++ b/big5/operations/default.json
@@ -886,12 +886,16 @@
       "name": "cardinality-agg-high",
       "operation-type": "search",
       "index": "{{index_name | default('big5')}}",
+      "request-timeout": 1800,
       "body": {
         "size": 0,
         "aggs": {
           "agent": {
             "cardinality": {
-              "field": "agent.name"
+             "field": "{{cardinality_agg_high_field | default('event.id')}}"
+              {% if distribution_version.split('.') | map('int') | list  >= "2.19.1".split('.') | map('int') | list and distribution_version.split('.') | map('int') | list  < "6.0.0".split('.') | map('int') | list %}
+              ,"execution_hint":"ordinals"
+              {% endif %}
             }
           }
         }