diff --git a/rust/cubestore/cubestore/src/streaming/kafka_post_processing.rs b/rust/cubestore/cubestore/src/streaming/kafka_post_processing.rs
index 4f47517e62e9e..79eb7f47d3592 100644
--- a/rust/cubestore/cubestore/src/streaming/kafka_post_processing.rs
+++ b/rust/cubestore/cubestore/src/streaming/kafka_post_processing.rs
@@ -470,16 +470,45 @@ impl KafkaPostProcessPlanner {
     }
 
     fn get_source_unique_column(&self, expr: &Expr) -> Result<Column, CubeError> {
+        fn find_column_name(expr: &Expr) -> Result<Option<String>, CubeError> {
+            match expr {
+                Expr::Column(c) => Ok(Some(c.name.clone())),
+                Expr::Alias(e, _) => find_column_name(&**e),
+                Expr::ScalarUDF { args, .. } => {
+                    let mut column_name: Option<String> = None;
+                    for arg in args {
+                        if let Some(name) = find_column_name(arg)? {
+                            if let Some(existing_name) = &column_name {
+                                if existing_name != &name {
+                                    return Err(CubeError::user(
+                                        format!("Scalar function can only use a single column, expression: {:?}", expr),
+                                    ));
+                                }
+                            } else {
+                                column_name = Some(name);
+                            }
+                        }
+                    }
+                    Ok(column_name)
+                }
+                _ => Ok(None),
+            }
+        }
+
         let source_name = match expr {
             Expr::Column(c) => Ok(c.name.clone()),
             Expr::Alias(e, _) => match &**e {
                 Expr::Column(c) => Ok(c.name.clone()),
+                Expr::ScalarUDF { .. } => find_column_name(expr)?.ok_or_else(|| {
+                    CubeError::user(format!("Scalar function must contain at least one column, expression: {:?}", expr))
+                }),
                 _ => Err(CubeError::user(format!(
-                    "Unique key can't be an expression in kafka streaming queries"
+                    "Unique key can't be an expression in kafka streaming queries, expression: {:?}",
+                    expr
                 ))),
             },
             _ => Err(CubeError::user(
-                "All expressions must have aliases in kafka streaming queries".to_string(),
+                format!("All expressions must have aliases in kafka streaming queries, expression: {:?}", expr),
             )),
         }?;
 
diff --git a/rust/cubestore/cubestore/src/streaming/mod.rs b/rust/cubestore/cubestore/src/streaming/mod.rs
index f73426df12b33..90c90ba0d59d1 100644
--- a/rust/cubestore/cubestore/src/streaming/mod.rs
+++ b/rust/cubestore/cubestore/src/streaming/mod.rs
@@ -1710,6 +1710,24 @@ mod tests {
                             unique key (`message_id`, `an_id`) INDEX by_anonymous(`message_id`) location 'stream://kafka/EVENTS_BY_TYPE/0', 'stream://kafka/EVENTS_BY_TYPE/1'")
                 .await
                 .expect_err("Validation should fail");
+
+            service
+                .exec_query("CREATE TABLE test.events_by_type_6 (`ANONYMOUSID` text, `MESSAGEID` text, `FILTER_ID` int, `TIMESTAMP` timestamp, `TIMESTAMP_SECOND` timestamp) \
+                            WITH (\
+                                  stream_offset = 'earliest',
+                                  select_statement = 'SELECT \
+                                        ANONYMOUSID, MESSAGEID, FILTER_ID, TIMESTAMP, \
+                                        PARSE_TIMESTAMP(FORMAT_TIMESTAMP(CONVERT_TZ(TIMESTAMP, \\'UTC\\', \\'UTC\\'), \\'yyyy-MM-dd\\'\\'T\\'\\'HH:mm:ss.000\\'), \\'yyyy-MM-dd\\'\\'T\\'\\'HH:mm:ss.SSS\\', \\'UTC\\') `TIMESTAMP_SECOND` \
+                                   FROM EVENTS_BY_TYPE \
+                            WHERE PARSE_TIMESTAMP(TIMESTAMP, \\'yyyy-MM-dd\\'\\'T\\'\\'HH:mm:ss.SSSX\\', \\'UTC\\') >= PARSE_TIMESTAMP(\\'1970-01-01T01:00:00.000Z\\', \\'yyyy-MM-dd\\'\\'T\\'\\'HH:mm:ss.SSSX\\', \\'UTC\\') \
+                            AND
+                            PARSE_TIMESTAMP(TIMESTAMP, \\'yyyy-MM-dd\\'\\'T\\'\\'HH:mm:ss.SSSX\\', \\'UTC\\') < PARSE_TIMESTAMP(\\'1970-01-01T01:10:00.000Z\\', \\'yyyy-MM-dd\\'\\'T\\'\\'HH:mm:ss.SSSX\\', \\'UTC\\') \
+                            \
+                            '\
+                            ) \
+                            unique key (`ANONYMOUSID`, `MESSAGEID`, `FILTER_ID`, `TIMESTAMP`, `TIMESTAMP_SECOND`) INDEX by_anonymous(`ANONYMOUSID`, `TIMESTAMP_SECOND`,`TIMESTAMP`) location 'stream://kafka/EVENTS_BY_TYPE/0', 'stream://kafka/EVENTS_BY_TYPE/1'")
+                .await
+                .unwrap();
         })
             .await;
     }