Migrating from PostgreSQL to CedarDB
CedarDB is highly PostgreSQL compatible and works with most PostgreSQL tools out of the box, so you can move a PostgreSQL database to CedarDB with the tools you already know. The recipes in this section copy a PostgreSQL database into CedarDB once, or keep copying changes until you switch your application over. They work for self-hosted PostgreSQL and managed services such as Amazon RDS, Aurora, Google Cloud SQL, and Azure Database for PostgreSQL, and for self-hosted CedarDB and CedarDB Cloud alike.
Recipes
| Recipe | Downtime | What arrives in CedarDB | Use it when |
|---|---|---|---|
| Copy with pg_dump | For the duration of the copy | Complete schema with keys, indexes, defaults, identity columns, views, owners, and privileges | You want the simplest setup and can stop writes to PostgreSQL while the data is copied. Needs only the PostgreSQL client tools. |
| Migrate with minimal downtime | During the switchover only | Complete schema, as with pg_dump | Your application must keep writing to PostgreSQL until a short switchover. Uses pg_dump for the schema and Debezium for the data. |
| Replicate with AWS DMS | During the switchover only | Tables created by DMS with columns and primary keys, or the schema you created beforehand | Your PostgreSQL runs on Amazon RDS or Aurora and you want a managed AWS service. |
What to expect
- Schema.
pg_dumprestores tables, views, indexes, constraints, defaults, identity columns, owners, and privileges as they are in PostgreSQL. - Roles and privileges. The recipes copy roles with
pg_dumpall, including their passwords, so applications keep their credentials. Privileges require a CedarDB enterprise license. With the community edition, the recipes keep the owners and skip the privileges. - Data types. Most PostgreSQL types arrive unchanged.
CedarDB does not support
timetz,xml, the geometric types, stored generated columns, andinfinitydates and timestamps. Thepg_dumpand minimal-downtime recipes show how to find and convert them first. - Downtime. A one-time copy needs a pause in writes for as long as the copy takes. With change data capture (Debezium or AWS DMS), the pause shrinks to the switchover.
- Validation. The
pg_dumpand minimal-downtime recipes end with queries that compare row counts and checksums on both sides, so you can check the copy before you switch.
Related tool documentation
| Tool | Description |
|---|---|
| Airbyte | Copy tables once with Airbyte’s Postgres connectors, also from sources other than PostgreSQL. Creates its own tables with extra Airbyte columns, without keys or indexes. |
| Debezium | Keep CedarDB continuously in sync with PostgreSQL through Kafka, or copy a snapshot once. Creates tables with columns and primary keys. |
| psql | The PostgreSQL command-line client used in the recipes. |
| Importing and working with CSV data | COPY options for CSV files. |
