<p>The following table describes the core concepts of DTS:</p> <table border="1" cellpadding="0" cellspacing="0"> <tbody> <tr> <td style="background-color:#ededed; vertical-align:top"> <p><strong>Concept</strong></p> </td> <td style="background-color:#ededed; vertical-align:top"> <p><strong>Description</strong></p> </td> </tr> <tr> <td style="vertical-align:top"> <p>Region</p> </td> <td style="vertical-align:top"> <p>Physical location that contains multiple data centers, for example, East China 1 and South China 1.</p> </td> </tr> <tr> <td style="vertical-align:top"> <p>Availability zone</p> </td> <td style="vertical-align:top"> <p>Physical area with independent power supplies and network in a region. The distance between availability zones is over 20 kilometers. Examples are Availability Zone A in East China 1 and Availability Zone B in South China 1.</p> </td> </tr> <tr> <td style="vertical-align:top"> <p>Source database</p> </td> <td style="vertical-align:top"> <p>Source of the data to be transferred.</p> </td> </tr> <tr> <td style="vertical-align:top"> <p>Target database</p> </td> <td style="vertical-align:top"> <p>Destination of the data to be transferred.</p> </td> </tr> <tr> <td style="vertical-align:top"> <p>Precheck</p> </td> <td style="vertical-align:top"> <p>Before you start an online migration task, check the key factors that might affect the task, including connectivity to the source database and permission on the target database. If an item fails precheck, fix it as instructed in the console and then run the precheck again. The task can be started only when all required items pass precheck.</p> </td> </tr> <tr> <td style="vertical-align:top"> <p>Structure migration</p> </td> <td style="vertical-align:top"> <p>DTS migrates the structure of the required objects from the source database to generate the same data structure in the target database. Tables, views, triggers, stored procedures, stored functions, and synonyms can be migrated.</p> <p>DTS performs data type mapping during the structure migration for heterogeneous databases, and converts the syntax based on the syntax of the source and target databases.</p> <p><img src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20200607171329-11b4efe495a1.png" style="height:20px; margin:0px; width:80px" />: Make sure the target database does not have any structures.</p> </td> </tr> <tr> <td style="vertical-align:top"> <p>Full migration</p> </td> <td style="vertical-align:top"> <p>DTS migrates all data (excluding the syntax of the structure objects) of the source database to the target database at one time.</p> <ul> <li>If the target database does not have target tables, you must perform structure migration first.</li> <li>If the target database has target tables and you select only full migration, the data that is written into the source database during the migration process will not be migrated to the target database.</li> </ul> </td> </tr> <tr> <td style="vertical-align:top"> <p>Incremental migration</p> </td> <td style="vertical-align:top"> <p>DTS migrates all the data that is modified after the incremental migration is enabled to the target database in near real time. The incremental migration tasks from RDS MySQL to RDS MySQL also synchronize structure objects.</p> <ul> <li>To stop a task that includes incremental migration, you must stop the task manually.</li> <li>If the target database does not have target tables and you select only incremental migration, you must manually create target tables in the target database.</li> </ul> </td> </tr> </tbody> </table>