diff --git a/br/tidb-lightning.toml b/br/tidb-lightning.toml index f23416a5f1928..8bbc519618d61 100644 --- a/br/tidb-lightning.toml +++ b/br/tidb-lightning.toml @@ -91,20 +91,22 @@ driver = "file" [conflict] -# Starting from v7.3.0, a new version of strategy is introduced to handle conflicting data. The default value is "". -# - "": TiDB Lightning does not detect or handle conflicting data. If the source file contains conflicting primary or unique key records, the subsequent step reports an error. In the logical import mode, the strategy is converted to "error" directly. +# Starting from v7.3.0, a new version of strategy is introduced to handle conflicting data. The default value is "". Starting from v8.0.0, TiDB Lightning optimizes the conflict strategy for both physical and logical import modes (experimental). +# - "": In the physical import mode, TiDB Lightning does not detect or handle conflicting data. If the source file contains conflicting primary or unique key records, the subsequent step reports an error. In the logical import mode, TiDB Lightning converts the "" strategy to the "error" strategy for processing. # - "error": When detecting conflicting primary or unique key records in the imported data, TiDB Lightning terminates the import and reports an error. # - "replace": When encountering conflicting primary or unique key records, TiDB Lightning retains the latest data and overwrites the old data. -# The conflict data are recorded in the `lightning_task_info.conflict_error_v2` table and the `conflict_records` table of the target TiDB cluster. -# You can manually insert the correct records into the target table based on your business requirements. -# Note that the target TiKV must be v5.2.0 or later versions. +# The conflicting data are recorded in the `lightning_task_info.conflict_error_v2` table (recording conflicting data detected by post-import conflict detection in the physical import mode) +# and the `conflict_records` table (recording conflicting data detected by preprocess conflict detection in both logical and physical import modes) of the target TiDB cluster. +# You can manually insert the correct records into the target table based on your application requirements. Note that the target TiKV must be v5.2.0 or later versions. # - "ignore": When encountering conflicting primary or unique key records, TiDB Lightning retains the old data and ignores the new data. This option can only be used in the logical import mode. strategy = "" -# Controls whether TiDB Lightning checks conflicts before the import. The default value is false, which means that TiDB Lightning only checks conflicts after the import. If it is set to true, TiDB Lightning checks conflicts both before and after the import. This parameter can be used only in the physical import mode (`tikv-importer.backend = "local"`). +# Controls whether to enable preprocess conflict detection, which check conflicts in the data before importing it to TiDB. In scenarios where the ratio of conflict records is greater than or equal to 1%, it is recommended to enable preprocess conflict detection for better performance in conflict detection. +# In other scenarios, it is recommended to disable it. The default value is false, indicating that TiDB Lightning only checks conflicts after the import. If you set it to true, TiDB Lightning checks conflicts both before and after the import. This parameter is experimental, and it can be used only in the physical import mode. # precheck-conflict-before-import = false -# Controls the maximum number of conflict errors that can be handled when strategy is "replace" or "ignore". You can set it only when strategy is "replace" or "ignore". The default value is 9223372036854775807, which means that almost all errors are tolerant. In physical import mode, this parameter takes effect only when `precheck-conflict-before-import` is enabled. +# Controls the maximum number of conflict errors that can be handled when strategy is "replace" or "ignore". You can set it only when strategy is "replace" or "ignore". The default value is 9223372036854775807, which means that almost all errors are tolerant. # threshold = 9223372036854775807 -# Controls the maximum number of records in the conflict_records table. The default value is 100. If the strategy is "ignore", the conflict records that are ignored are recorded; if the strategy is "replace", the conflict records that are overwritten are recorded. However, the "replace" strategy cannot record the conflict records in the logical import mode. In physical import mode, this parameter takes effect only when `precheck-conflict-before-import` is enabled. +# Controls the maximum number of records in the `conflict_records` table. The default value is 100. In the physical import mode, if the strategy is "replace", the conflict records that are overwritten are recorded. +# In the logical import mode, if the strategy is "ignore", the conflict records that are ignored are recorded; if the strategy is "replace", the conflict records can not be recorded. # max-record-rows = 100 [tikv-importer]