fix: handle Decimal64 properly in column_update_hll_cardinality (#18287)

fix: handle Decimal64 in `column_update_hll_cardinality`

Author: dantengsky

src/query/storages/fuse/src/io/write/stream/column_statistics.rs

@@ -194,6 +194,11 @@ fn column_update_hll_cardinality(col: &Column, ty: &DataType, hll: &mut ColumnDi
         }
         DataType::Decimal(_) => {
             match col {
+                Column::Decimal(DecimalColumn::Decimal64(col, _)) => {
+                    for v in col.iter() {
+                        hll.add_object(v);
+                    }
+                }
                 Column::Decimal(DecimalColumn::Decimal128(col, _)) => {
                     for v in col.iter() {
                         hll.add_object(v);

tests/sqllogictests/suites/base/issues/issue_18286.test

@@ -0,0 +1,18 @@
+# https://github.com/datafuselabs/databend/issues/18286
+
+statement ok
+create or replace database issue_18286;
+
+statement ok
+use issue_18286;
+
+statement ok
+create or replace table t( c DECIMAL(10, 2) not null);
+
+statement ok
+insert into t select number / 100 as c from numbers(100);
+
+query T
+select count(*) from t;
+----
+100