Tentang alur data untuk Oracle ke Cloud SQL untuk PostgreSQL
Tetap teratur dengan koleksi
Simpan dan kategorikan konten berdasarkan preferensi Anda.
Ada dua konsep penting yang perlu Anda pahami untuk mengetahui cara data mengalir
dari sumber ke instance tujuan: jenis migrasi dan fase migrasi. Database Migration Service mendukung dua jenis migrasi: berkelanjutan dan satu kali.
Hanya migrasi berkelanjutan yang tersedia untuk migrasi heterogen dari Oracle ke Cloud SQL untuk PostgreSQL.
Dengan migrasi berkelanjutan, data Anda dimigrasikan dalam dua fase: dump penuh, dan
Pengambilan Data Perubahan (CDC).
Fase dump penuh
Fase dump penuh adalah bagian pertama dari proses migrasi. Selama
dump penuh, Database Migration Service terhubung ke instance sumber Anda, membaca konten
database yang Anda pilih untuk migrasi, lalu memuat data ke instance tujuan Cloud SQL untuk PostgreSQL. Pada fase ini, Database Migration Service mengambil konten sebenarnya dari database Anda.
Selama fase dump penuh, Database Migration Service dapat membuka beberapa koneksi ke database sumber Anda untuk meningkatkan performa. Anda dapat mengonfigurasi jumlah
koneksi serentak saat
membuat tugas migrasi.
Untuk kontrol terperinci atas pergerakan data Anda, Anda juga dapat melakukan dump penuh dan memuat data ke instance tujuan sendiri, di luar Database Migration Service. Jika Anda memilih untuk melakukan fase ini secara manual, tugas migrasi Anda akan dimulai dengan fase CDC dan Database Migration Service akan mengharapkan Anda memberikan Nomor Perubahan Sistem (SCN) file log redo sebagai titik awal.
Pengambilan Data Perubahan (CDC)
Setelah fase dump penuh selesai (atau jika Anda memilih untuk melakukan dump penuh sendiri dan memulai dengan fase CDC), Database Migration Service akan beralih ke fase CDC yang terus memantau perubahan pada database sumber Anda, lalu mereplikasinya secara berkelanjutan di instance tujuan. Pada fase ini,
Database Migration Service tidak menyalin data aktual dari database sumber Anda: melainkan
membaca file log untuk mereplikasi perubahan di tujuan.
Database Migration Service menggunakan Oracle LogMiner API untuk mengakses dan mengurai file log redo Oracle yang diarsipkan di database sumber Anda. Sebelum Anda memigrasikan database Oracle ke Cloud SQL untuk PostgreSQL dengan Database Migration Service, sebaiknya sesuaikan setelan file redo log Oracle Anda untuk performa dan keakuratan data yang optimal. Untuk
mengetahui informasi selengkapnya, lihat
Menggunakan file log pengulangan Oracle.
[[["Mudah dipahami","easyToUnderstand","thumb-up"],["Memecahkan masalah saya","solvedMyProblem","thumb-up"],["Lainnya","otherUp","thumb-up"]],[["Sulit dipahami","hardToUnderstand","thumb-down"],["Informasi atau kode contoh salah","incorrectInformationOrSampleCode","thumb-down"],["Informasi/contoh yang saya butuhkan tidak ada","missingTheInformationSamplesINeed","thumb-down"],["Masalah terjemahan","translationIssue","thumb-down"],["Lainnya","otherDown","thumb-down"]],["Terakhir diperbarui pada 2025-09-01 UTC."],[[["\u003cp\u003eDatabase Migration Service utilizes two migration types, continuous and one-time, with only continuous migrations available for Oracle to Cloud SQL for PostgreSQL.\u003c/p\u003e\n"],["\u003cp\u003eContinuous migrations are divided into two phases: the full dump phase, which transfers the initial data to the destination, and the Change Data Capture (CDC) phase, which replicates subsequent changes.\u003c/p\u003e\n"],["\u003cp\u003eDuring the full dump phase, Database Migration Service copies data directly from the source database to the destination, with the option to adjust concurrent connection numbers for optimal performance.\u003c/p\u003e\n"],["\u003cp\u003eAlternatively, users can manually perform the full dump and then start the migration job with the CDC phase, providing the System Change Number (SCN) as the starting point.\u003c/p\u003e\n"],["\u003cp\u003eThe CDC phase relies on monitoring log files to replicate changes, using the Oracle LogMiner API to read and parse archived Oracle redo log files for continuous data synchronization.\u003c/p\u003e\n"]]],[],null,["# About data flow for Oracle to Cloud SQL for PostgreSQL\n\nThere are two important concepts you need to understand to know how data flows\nfrom your source to the destination instance: migration types and migration\nphases. Database Migration Service supports two types of migration: continuous and one-time.\nOnly continuous migrations are available for heterogeneous Oracle to\nCloud SQL for PostgreSQL migrations.\n\nWith continuous migrations, your data is migrated in two phases: full dump, and\nChange Data Capture (CDC).\n\nFull dump phase\n---------------\n\nThe **full dump phase** is the first part of the migration process. During\nfull dump, Database Migration Service connects to your source instance, reads the content\nof the databases you selected for migration, and then loads the data to the Cloud SQL for PostgreSQL\ndestination instance. In this phase, Database Migration Service captures actual contents\nof your database.\n\nDuring the full dump phase, Database Migration Service can open multiple connections to\nyour source databases for improved performance. You can configure the number of\nconcurrent connections when you\n[create a migration job](/database-migration/docs/oracle-to-postgresql/create-migration-job).\n\nFor granular control over your data movement, you can also perform the full dump\nand load the data to the destination instance on your own, outside of\nDatabase Migration Service. If you choose to perform this phase manually, your migration\njob will start with the CDC phase instead and Database Migration Service\nwill expect that you provide the System Change Number (SCN) of your redo log\nfiles as the starting point.\n\nChange Data Capture (CDC)\n-------------------------\n\nWhen the **full dump** phase is over (or if you choose to perform the full\ndump yourself and start with the CDC phase), Database Migration Service switches to the\nCDC phase where it keeps monitoring your source databases for changes, and then\ncontinuously replicates them on the destination instance. In this phase,\nDatabase Migration Service doesn't copy actual data from your source databases: instead\nit reads log files to replicate changes in the destination.\n\nDatabase Migration Service uses the Oracle LogMiner API to access and parse archived Oracle\nredo log files in your source database. Before you migrate your Oracle databases\nto Cloud SQL for PostgreSQL with Database Migration Service, we recommend that you adjust your\nOracle redo log files settings for optimal performance and data fidelity. For\nmore information, see\n[Work with Oracle redo log files](/database-migration/docs/oracle-to-postgresql/work-with-oracle-database-redo-log-files)."]]
