Question

我正在使用AWS Database Migration Service（DMS）创建复制任务。我注意到TaskSettings JSON中有一个名为CharacterSetSettings的属性。但是，似乎没有有关此属性的文档。

我尝试在文档和Google中搜索该属性，但没有出现。

任务设置JSON：

{
    "TargetMetadata": {
        "TargetSchema": "",
        "SupportLobs": true,
        "FullLobMode": false,
        "LobChunkSize": 0,
        "LimitedSizeLobMode": true,
        "LobMaxSize": 256,
        "InlineLobMaxSize": 0,
        "LoadMaxFileSize": 0,
        "ParallelLoadThreads": 0,
        "ParallelLoadBufferSize": 0,
        "BatchApplyEnabled": false,
        "TaskRecoveryTableEnabled": false
    },
    "FullLoadSettings": {
        "TargetTablePrepMode": "TRUNCATE_BEFORE_LOAD",
        "CreatePkAfterFullLoad": false,
        "StopTaskCachedChangesApplied": false,
        "StopTaskCachedChangesNotApplied": false,
        "MaxFullLoadSubTasks": 8,
        "TransactionConsistencyTimeout": 1000,
        "CommitRate": 10000
    },
    "Logging": {
        "EnableLogging": true,
        "LogComponents": [
            {
                "Id": "SOURCE_UNLOAD",
                "Severity": "LOGGER_SEVERITY_DEFAULT"
            },
            {
                "Id": "TARGET_LOAD",
                "Severity": "LOGGER_SEVERITY_DEFAULT"
            },
            {
                "Id": "SOURCE_CAPTURE",
                "Severity": "LOGGER_SEVERITY_DEFAULT"
            },
            {
                "Id": "TARGET_APPLY",
                "Severity": "LOGGER_SEVERITY_DEFAULT"
            },
            {
                "Id": "TASK_MANAGER",
                "Severity": "LOGGER_SEVERITY_DEFAULT"
            }
        ],
        "CloudWatchLogGroup": "dms-tasks-altitude-staging-to-prod-instance",
        "CloudWatchLogStream": "dms-task-RU2FBO6SGUASAODLXHJ63OYDAM"
    },
    "ControlTablesSettings": {
        "historyTimeslotInMinutes": 5,
        "ControlSchema": "control",
        "HistoryTimeslotInMinutes": 5,
        "HistoryTableEnabled": true,
        "SuspendedTablesTableEnabled": true,
        "StatusTableEnabled": true
    },
    "StreamBufferSettings": {
        "StreamBufferCount": 3,
        "StreamBufferSizeInMB": 8,
        "CtrlStreamBufferSizeInMB": 5
    },
    "ChangeProcessingDdlHandlingPolicy": {
        "HandleSourceTableDropped": true,
        "HandleSourceTableTruncated": true,
        "HandleSourceTableAltered": true
    },
    "ErrorBehavior": {
        "DataErrorPolicy": "LOG_ERROR",
        "DataTruncationErrorPolicy": "LOG_ERROR",
        "DataErrorEscalationPolicy": "SUSPEND_TABLE",
        "DataErrorEscalationCount": 0,
        "TableErrorPolicy": "SUSPEND_TABLE",
        "TableErrorEscalationPolicy": "STOP_TASK",
        "TableErrorEscalationCount": 0,
        "RecoverableErrorCount": -1,
        "RecoverableErrorInterval": 5,
        "RecoverableErrorThrottling": true,
        "RecoverableErrorThrottlingMax": 1800,
        "ApplyErrorDeletePolicy": "IGNORE_RECORD",
        "ApplyErrorInsertPolicy": "LOG_ERROR",
        "ApplyErrorUpdatePolicy": "LOG_ERROR",
        "ApplyErrorEscalationPolicy": "LOG_ERROR",
        "ApplyErrorEscalationCount": 0,
        "ApplyErrorFailOnTruncationDdl": false,
        "FullLoadIgnoreConflicts": true,
        "FailOnTransactionConsistencyBreached": false,
        "FailOnNoTablesCaptured": false
    },
    "ChangeProcessingTuning": {
        "BatchApplyPreserveTransaction": true,
        "BatchApplyTimeoutMin": 1,
        "BatchApplyTimeoutMax": 30,
        "BatchApplyMemoryLimit": 500,
        "BatchSplitSize": 0,
        "MinTransactionSize": 1000,
        "CommitTimeout": 1,
        "MemoryLimitTotal": 1024,
        "MemoryKeepTime": 60,
        "StatementCacheSize": 50
    },
    "ValidationSettings": {
        "EnableValidation": true,
        "ValidationMode": "ROW_LEVEL",
        "ThreadCount": 5,
        "PartitionSize": 10000,
        "FailureMaxCount": 10000,
        "RecordFailureDelayInMinutes": 5,
        "RecordSuspendDelayInMinutes": 30,
        "MaxKeyColumnSize": 8096,
        "TableFailureMaxCount": 1000,
        "ValidationOnly": false,
        "HandleCollationDiff": false,
        "RecordFailureDelayLimitInMinutes": 0
    },
    "PostProcessingRules": null,
    "CharacterSetSettings": null
}

CharacterSetSettings上应该有文档。我希望文档会在Specifying Task Settings for AWS Database Migration Service Tasks - AWS Database Migration Service上列出。

Answer 1

您正在搜索Character Substitution Task Settings。这似乎是很新的。

您可以指定复制任务执行字符目标数据库上所有源数据库列的替换使用AWS DMS STRING或WSTRING数据类型。您可以配置具有以下端点的任何任务的字符替换源数据库和目标数据库：

源数据库：

Oracle

Microsoft SQL Server

MySQL

PostgreSQL

SAP Adaptive Server Enterprise（ASE）

IBM Db2 LUW

目标数据库：

Oracle

Microsoft SQL Server

MySQL

PostgreSQL

SAP Adaptive Server Enterprise（ASE）

Amazon Redshift

在开始通过表映射指定的任何全局或表级转换之前，复制任务会完成所有指定的字符替换。

对象看起来像这样：

"CharacterSetSettings": {
    "CharacterReplacements": [ {
        "SourceCharacterCodePoint": int,
        "TargetCharacterCodePoint": int
        },
        [...]
    ],
    "CharacterSetSupport": {
        "CharacterSet": str,
        "ReplaceWithCharacterCodePoint": int
    }
}

DMS分两个阶段处理字符替换：

在第一阶段，CharacterReplacements是一个对象列表，描述了一个Unicode代码点与另一个Unicode代码点的一次替换。例如，如果要将b替换为a，请将SourceCharacterCodePoint设置为62，将TargetCharacterCodePoint设置为61。
在第二阶段，设置CharacterSetSupport使DMS验证所有字符对于CharacterSet（即UTF-8，UTF-16，ISO-8859-1）都是有效的。文档中的完整列表）编码。如果发现无效字符，它们将被ReplaceWithCharacterCodePoint替换。

对于两个阶段，都可以使用特殊代码点0来删除字符。

“ CharacterSetSettings”的文档在哪里？

1 个答案: