diff --git a/system-variables.md b/system-variables.md index 2d1357acc582a..9810c5dfa60ba 100644 --- a/system-variables.md +++ b/system-variables.md @@ -1128,7 +1128,8 @@ MPP is a distributed computing framework provided by the TiFlash engine, which a - Persists to cluster: Yes - Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No - Default value: `2`. The default value is `1` for v7.4.0 and earlier versions. -- This variable specifies the concurrency of reading and writing statistics for a partitioned table when TiDB analyzes the partitioned table. +- Range: `[1, 128]` +- This variable specifies the concurrency for writing collected statistics for a partitioned table when TiDB analyzes it. ### tidb_analyze_version New in v5.1.0 @@ -4954,7 +4955,7 @@ SHOW WARNINGS; - Type: Boolean - Default value: Before v7.2.0, the default value is `OFF`. Starting from v7.2.0, the default value is `ON`. - Specifies whether to remove `ORDER BY` clause in a subquery. -- In the ISO/IEC SQL standard, `ORDER BY` is mainly used to sort the results of top-level queries. For subqueries, the standard does not require that the results be sorted by `ORDER BY`. +- In the ISO/IEC SQL standard, `ORDER BY` is mainly used to sort the results of top-level queries. For subqueries, the standard does not require that the results be sorted by `ORDER BY`. - To sort subquery results, you can usually handle it in the outer query, such as using the window function or using `ORDER BY` again in the outer query. Doing so ensures the order of the final result set. ### tidb_replica_read New in v4.0