[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間：2025-09-01 (世界標準時間)。"],[],[],null,["# Database Migration Service for heterogeneous Oracle to Cloud SQL for PostgreSQL\n\nWith Database Migration Service, you can convert your Oracle database schema,\ntables, and code objects to PostgreSQL syntax, and then migrate\ndata from your Oracle databases to Cloud SQL for PostgreSQL.\nDatabase Migration Service offers support for multiple different Oracle\nofferings, including Bare Metal Solution, Oracle Real Application Clusters (RAC),\nand self-managed instances.\n\nThis page provides an overview of the key Database Migration Service features\nfor heterogeneous Oracle to Cloud SQL for PostgreSQL migrations:\n\n- [Supported source and destination](#supported-src-and-dest) lists all Oracle\n versions supported by Database Migration Service.\n\n- [Code and schema conversion](#conversion) describes how Database Migration Service\n can help you convert your schemas, tables, and other objects from\n Oracle syntax to PostgreSQL syntax.\n\n- [Continuous migrations data flow](#data-flow-migration-types) provides an end-to-end overview\n of how your data moves in Google Cloud during the migration process.\n\n- [Monitoring](#monitoring)\n gives an introduction for logs and metrics that can\n help you observe the progress and health of your migration job.\n\n- [Migration security](#securing-migration-jobs) looks at encryption features offered by\n Database Migration Service.\n\nSupported source and destination databases\n------------------------------------------\n\nDatabase Migration Service supports the following Oracle databases as migration sources:\n\n- Amazon RDS for Oracle\n- Self-hosted deployments, including:\n - Oracle Single Instance Database Deployment\n - Oracle Exadata\n - Oracle Active Data Guard\n - Oracle Real Application Clusters (RAC)\n\nFull support also depends on your source Oracle version.\nThe following table lists all supported versions for heterogeneous Oracle migrations:\n\nUnsupported source databases\n----------------------------\n\nDatabase Migration Service doesn't support migrating from Oracle Autonomous Database.\n\nCode and schema conversion\n--------------------------\n\nDatabase Migration Service conversion workspaces provide an interactive editor experience\nwhere you can convert your schemas, tables, and other objects from\nOracle syntax to PostgreSQL syntax. Interactive conversion workspaces\nalso provide support for Gemini-assisted workflows with code\nexplainability and conversion issue fixing.\n\nTo learn more, see\n[Conversion workspaces](/database-migration/docs/oracle-to-postgresql/about-conversion-workspaces).\n\nContinuous migrations data flow\n-------------------------------\n\nFor heterogeneous Oracle migrations to PostgreSQL,\nDatabase Migration Service supports the continuous migration flow. In this approach,\nyour data is first loaded from a full dump, and then continuously updated based on\ndata change information surfaced from\n[database log files](/database-migration/docs/oracle-to-postgresql/about-data-flow#cdc).\n[](#lightbox-trigger) **Figure 1.** Data movement during Database Migration Service for Oracle heterogeneous migrations. (click to enlarge)\n\nAt a high level, your data moves through the migration phases as follows:\n\n1. You use Database Migration Service conversion workspace to convert your schemas,\n tables, and other objects from Oracle syntax to PostgreSQL syntax.\n\n Oracle databases can often have several thousand objects\n whose schema you need to convert. With Database Migration Service, you can divide your\n work into multiple phases. Database Migration Service can connect to your source\n databases and pull the required schema information when needed.\n2.\n When you finish translating all your entities to PostgreSQL syntax,\n you apply the schema to the databases in the destination instance.\n\n\n The goal of this stage is to prepare your destination databases so that\n Database Migration Service can later replicate the data from source tables to their\n correct equivalents in Cloud SQL for PostgreSQL.\n\n Once your schema is applied, you can begin the data migration.\n3. The **full dump phase** is the first part of the migration process.\n There are two ways in which you can complete full dump:\n\n - Automatic: Database Migration Service connects to your source instance, reads\n the contents of the tables you selected for migration, and then loads\n the data to the Cloud SQL for PostgreSQL destination instance.\n\n In this phase, Database Migration Service captures actual contents of your\n database.\n - Manual: You can skip the full dump phase and perform it yourself outside Database Migration Service. If you do, you can start the migration process with the change data capture (CDC) phase by providing an Oracle System Change Number as the starting point for replication.\n4. When the full dump phase is over, Database Migration Service switches to the\n **CDC phase**. During CDC, Database Migration Service keeps monitoring\n your source databases for changes, and then continuously replicates them on the\n destination instance.\n\n In this phase, Database Migration Service doesn't copy actual data from your source\n tables: instead, it reads information extracted from\n [database log files](/database-migration/docs/oracle-to-postgresql/about-data-flow#cdc)\n to replicate changes in the destination. For more information about this\n mechanism, see [Change Data Capture](/database-migration/docs/oracle-to-postgresql/about-data-flow#cdc).\n\nYou can stop the ongoing replication and promote the migration job when you want\nto switch your application so that it uses the Cloud SQL for PostgreSQL\ndestination instance as the production database. For a detailed, step-by-step\nmigration guide, see\n[Oracle to Cloud SQL for PostgreSQL migration guide](/database-migration/docs/oracle-to-postgresql/guide).\n\nMonitoring\n----------\n\n[](#lightbox-trigger) **Figure 2.** Sample observability diagram in Database Migration Service. (click to enlarge)\n\nDatabase Migration Service provides extensive logging and observability capabilities\nto help you monitor the migration progress. These features include real-time\ndiagnostics for replication delay and CDC progress,\nas well as detailed logs for Cloud SQL for PostgreSQL destination instance health\nand migration job state.\n\nFor more details, see\n[Migration job metrics](/database-migration/docs/oracle-to-postgresql/migration-job-metrics).\n\nMigration security\n------------------\n\nDatabase Migration Service provides multiple encryption mechanisms you can use\nfor additional security during the migration process. These mechanisms include:\n\n- SSL/TLS certificates for encrypting the network connections between\n Database Migration Service and source databases. For more details, see\n [Encryption overview](/database-migration/docs/oracle-to-postgresql/encrypt-connections-with-certificates).\n\n- Encryption certificates for securing data movement during full dump and CDC\n phases. For more details, see\n [CMEK for migration jobs](/database-migration/docs/oracle-to-postgresql/cmek-for-migration-jobs).\n\nWhat's next\n-----------\n\n- To learn more about Oracle data type and feature support in\n Database Migration Service, see\n [Known limitations](/database-migration/docs/oracle-to-postgresql/known-limitations).\n\n- To get a complete, step-by-step migration walkthrough, see\n [Oracle to Cloud SQL for PostgreSQL migration guide](/database-migration/docs/oracle-to-postgresql/guide)."]]
