Update release-6.4.0.md

releases/release-6.4.0.md

@@ -283,7 +283,7 @@ In v6.4.0-DMR, the key new features and improvements are as follows:
 | [`tidb_auto_analyze_partition_batch_size`](/system-variables.md#tidb_auto_analyze_partition_batch_size-new-in-v640) | Newly added | Specifies the number of partitions that TiDB can [automatically analyzes](/statistics.md#automatic-update) at a time when analyzing a partitioned table (which means automatically collecting statistics on a partitioned table). The default value is `1`.|
 | [`tidb_enable_external_ts_read`](/system-variables.md#tidb_enable_external_ts_read-new-in-v640) | Newly added | Controls whether TiDB reads data with the timestamp specified by [`tidb_external_ts`](/system-variables.md#tidb_external_ts-new-in-v640). The default value is `OFF`. |
 | [`tidb_enable_gogc_tuner`](/system-variables.md#tidb_enable_gogc_tuner-new-in-v640) | Newly added | Controls whether to enable GOGC Tuner. The default value is `ON`. |
-| [`tidb_enable_reuse_chunk`](/system-variables.md#last_sql_use_alloc-new-in-v640) | Newly added | Controls whether TiDB enables chunk objects cache. The default value is `ON`, meaning that TiDB prefers to use the cached chunk object and only requests from the system if the requested object is not in the cache. If the value is `OFF`, TiDB requests chunk objects from the system directly. |
+| [`tidb_enable_reuse_chunk`](/system-variables.md#tidb_enable_reuse_chunk-in-v640) | Newly added | Controls whether TiDB enables chunk objects cache. The default value is `ON`, meaning that TiDB prefers to use the cached chunk object and only requests from the system if the requested object is not in the cache. If the value is `OFF`, TiDB requests chunk objects from the system directly. |
 | [`tidb_enable_prepared_plan_cache_memory_monitor`](/system-variables.md#tidb_enable_prepared_plan_cache_memory_monitor-new-in-v640) | Newly added | Controls whether to count the memory consumed by the execution plans cached in the Prepared Plan Cache. The default value is `ON`.|
 | [`tidb_external_ts`](/system-variables.md#tidb_external_ts-new-in-v640) | Newly added | The default value is `0`. If [`tidb_enable_external_ts_read`](/system-variables.md#tidb_enable_external_ts_read-new-in-v640) is set to `ON`, TiDB reads data with the timestamp specified by this variable.|
 | [`tidb_gogc_tuner_threshold`](/system-variables.md#tidb_gogc_tuner_threshold-new-in-v640) | Newly added | Specifies the maximum memory threshold for tuning GOGC. When the memory exceeds this threshold, GOGC Tuner stops working. The default value is `0.6`. |