update pre_split_regions usage scenario (#18563)

pingcap · Aug 14, 2024 · 5bf6008 · 5bf6008
1 parent ab98ce6
commit 5bf6008
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/sql-statements/sql-statement-split-region.md b/sql-statements/sql-statement-split-region.md
@@ -355,11 +355,11 @@ You can specify the partition to be split.
 
 ## pre_split_regions
 
-To have evenly split Regions when a table is created, it is recommended you use `SHARD_ROW_ID_BITS` together with `PRE_SPLIT_REGIONS`. When a table is created successfully, `PRE_SPLIT_REGIONS` pre-spilts tables into the number of Regions as specified by `2^(PRE_SPLIT_REGIONS)`.
+When creating a table with the `AUTO_RANDOM` or `SHARD_ROW_ID_BITS` attribute, you can also specify the `PRE_SPLIT_REGIONS` option if you want to evenly pre-split the table into Regions immediately after the table is created. The number of pre-split Regions for a table is `2^(PRE_SPLIT_REGIONS)`.
 
 > **Note:**
 >
-> The value of `PRE_SPLIT_REGIONS` must be less than or equal to that of `SHARD_ROW_ID_BITS`.
+> The value of `PRE_SPLIT_REGIONS` must be less than or equal to that of `SHARD_ROW_ID_BITS` or `AUTO_RANDOM`.
 
 The `tidb_scatter_region` global variable affects the behavior of `PRE_SPLIT_REGIONS`. This variable controls whether to wait for Regions to be pre-split and scattered before returning results after the table creation. If there are intensive writes after creating the table, you need to set the value of this variable to `1`, then TiDB will not return the results to the client until all the Regions are split and scattered. Otherwise, TiDB writes the data before the scattering is completed, which will have a significant impact on write performance.
 
@@ -384,7 +384,7 @@ region4:   [ 3<<61     ,  +inf  )
 
 > **Note:**
 >
-> The Region split by the Split Region statement is controlled by the [Region merge](/best-practices/pd-scheduling-best-practices.md#region-merge) scheduler in PD. To avoid PD re-merging the newly split Region soon after, you need to [dynamically modify](/pd-control.md) configuration items related to the Region merge feature.
+> The Region split by the Split Region statement is controlled by the [Region merge](/best-practices/pd-scheduling-best-practices.md#region-merge) scheduler in PD. To avoid PD re-merging the newly split Region soon after, you need to use [table attributes](/table-attributes.md) or [dynamically modify](/pd-control.md) configuration items related to the Region merge feature.
 
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