diff --git a/java/connector-node/risingwave-sink-cassandra/src/main/java/com/risingwave/connector/CassandraConfig.java b/java/connector-node/risingwave-sink-cassandra/src/main/java/com/risingwave/connector/CassandraConfig.java
index 80181fe26090c..bfc40111818a4 100644
--- a/java/connector-node/risingwave-sink-cassandra/src/main/java/com/risingwave/connector/CassandraConfig.java
+++ b/java/connector-node/risingwave-sink-cassandra/src/main/java/com/risingwave/connector/CassandraConfig.java
@@ -107,7 +107,7 @@ public Integer getMaxBatchRows() {
     public CassandraConfig withMaxBatchRows(Integer maxBatchRows) {
         if (maxBatchRows > 65536 || maxBatchRows < 1) {
             throw new IllegalArgumentException(
-                    "cassandra.max_batch_rows must be <= 65535 and >= 1");
+                    "Cassandra sink option: maxBatchRows must be <= 65535 and >= 1");
         }
         this.maxBatchRows = maxBatchRows;
         return this;
@@ -119,7 +119,8 @@ public Integer getRequestTimeoutMs() {
 
     public CassandraConfig withRequestTimeoutMs(Integer requestTimeoutMs) {
         if (requestTimeoutMs < 1) {
-            throw new IllegalArgumentException("cassandra.request_timeout_ms must be >= 1");
+            throw new IllegalArgumentException(
+                    "Cassandra sink option: requestTimeoutMs must be >= 1");
         }
         this.requestTimeoutMs = requestTimeoutMs;
         return this;
diff --git a/src/connector/src/sink/encoder/json.rs b/src/connector/src/sink/encoder/json.rs
index a51b9830ec6de..64a06ff70770f 100644
--- a/src/connector/src/sink/encoder/json.rs
+++ b/src/connector/src/sink/encoder/json.rs
@@ -207,6 +207,7 @@ fn datum_to_json_object(
             if let CustomJsonType::BigQuery = custom_json_type
                 && matches!(field.data_type(), DataType::List(_))
             {
+                // Bigquery need to convert null of array to empty array https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types
                 return Ok(Value::Array(vec![]));
             } else {
                 return Ok(Value::Null);
diff --git a/src/connector/with_options_sink.yaml b/src/connector/with_options_sink.yaml
index 35b06ec33fb76..28b492f0c80ea 100644
--- a/src/connector/with_options_sink.yaml
+++ b/src/connector/with_options_sink.yaml
@@ -17,6 +17,10 @@ BigQueryConfig:
   - name: bigquery.table
     field_type: String
     required: true
+  - name: bigquery.max_batch_rows
+    field_type: usize
+    required: false
+    default: '1024'
   - name: region
     field_type: String
     required: false