[bugfix](MultiPartition)let the user set the prefix of the MultiParti…

…tion (#33820)

fe/fe-common/src/main/java/org/apache/doris/common/Config.java

@@ -1499,6 +1499,14 @@ public class Config extends ConfigBase {
     @ConfField(mutable = true, masterOnly = true)
     public static int max_dynamic_partition_num = 500;
 
+    /**
+     * Use this parameter to set the partition name prefix for multi partition,
+     * Only multi partition takes effect, not dynamic partitions.
+     * The default prefix is "p_".
+     */
+     @ConfField(mutable = true, masterOnly = true)
+     public static String multi_partition_name_prefix = "p_";
+
     /**
      * Used to limit the maximum number of partitions that can be created when creating multi partition,
      * to avoid creating too many partitions at one time.

fe/fe-core/src/main/java/org/apache/doris/analysis/MultiPartitionDesc.java

@@ -50,7 +50,6 @@ public class MultiPartitionDesc implements AllPartitionDesc {
 
 
 
-    private final String partitionPrefix = "p_";
     private LocalDateTime startTime;
     private LocalDateTime endTime;
 
@@ -72,6 +71,7 @@ public class MultiPartitionDesc implements AllPartitionDesc {
             TimestampArithmeticExpr.TimeUnit.YEAR
     );
 
+    private final String partitionPrefix = Config.multi_partition_name_prefix;
     private final Integer maxAllowedLimit = Config.max_multi_partition_num;
 
     public MultiPartitionDesc(PartitionKeyDesc partitionKeyDesc,