[Bug](exec) Fix min max push agg error read char column

be/src/olap/rowset/segment_v2/column_reader.cpp

@@ -464,6 +464,9 @@ Status ColumnReader::next_batch_of_zone_map(size_t* n, vectorized::MutableColumn
     } else {
         if (is_string) {
             auto sv = (StringRef*)max_value->cell_ptr();
+            if (type == FieldType::OLAP_FIELD_TYPE_CHAR) {
+                *sv = sv->trim_tail_padding_zero();
+            }
             dst->insert_data(sv->data, sv->size);
         } else {
             dst->insert_many_fix_len_data(static_cast<const char*>(max_value->cell_ptr()), 1);
@@ -476,6 +479,9 @@ Status ColumnReader::next_batch_of_zone_map(size_t* n, vectorized::MutableColumn
     } else {
         if (is_string) {
             auto sv = (StringRef*)min_value->cell_ptr();
+            if (type == FieldType::OLAP_FIELD_TYPE_CHAR) {
+                *sv = sv->trim_tail_padding_zero();
+            }
             dst->insert_data_repeatedly(sv->data, sv->size, size);
         } else {
             // TODO: the work may cause performance problem, opt latter

be/src/pipeline/exec/cache_source_operator.h

@@ -58,8 +58,8 @@ class CacheSourceLocalState final : public PipelineXLocalState<DataQueueSharedSt
     int64_t _version = 0;
     std::vector<vectorized::BlockUPtr> _local_cache_blocks;
     std::vector<int> _slot_orders;
-    size_t _current_query_cache_bytes = 0;
-    size_t _current_query_cache_rows = 0;
+    int64_t _current_query_cache_bytes = 0;
+    int64_t _current_query_cache_rows = 0;
     bool _need_insert_cache = true;
 
     QueryCacheHandle _query_cache_handle;

be/src/vec/common/string_ref.cpp

@@ -41,6 +41,17 @@ StringRef StringRef::trim() const {
     return StringRef(data + begin, end - begin + 1);
 }
 
+StringRef StringRef::trim_tail_padding_zero() const {
+    // Remove trailing padding zero.
+    int64_t end = size - 1;
+
+    while (end >= 0 && data[end] == '\0') {
+        --end;
+    }
+
+    return StringRef(data, end + 1);
+}
+
 StringRef StringRef::trim_whitespace() const {
     // Remove leading and trailing whitespace.
     int64_t begin = 0;

be/src/vec/common/string_ref.h

@@ -220,6 +220,7 @@ struct StringRef {
 
     // Trims leading and trailing spaces.
     StringRef trim() const;
+    StringRef trim_tail_padding_zero() const;
     StringRef trim_whitespace() const;
     StringRef trim_quote() const;
 

regression-test/suites/query_p0/aggregate/support_type/min/min.groovy

@@ -97,6 +97,9 @@ suite("min") {
     qt_min_double """select min(col_double) from d_table;"""
 
     qt_min_char """select min(col_char) from d_table;"""
+    // Test length(min(col_char)) with different disable_nereids_rules settings
+    sql "set disable_nereids_rules='';"
+    qt_min_char_length_default """select length(min(col_char)) from d_table;"""
     qt_min_varchar """select min(col_varchar) from d_table;"""
     qt_min_string """select min(col_string) from d_table;"""
 
@@ -110,4 +113,4 @@ suite("min") {
 
     qt_min_ipv4 """select min(col_ipv4) from d_table;"""
     qt_min_ipv6 """select min(col_ipv6) from d_table;"""
-}
+}