Cetus vs SPQR
Cetus
github.comSPQR
docs.pg-sharding.techSide by side
| Figure | Cetus | SPQR |
|---|---|---|
| Price from | — | Free |
| Free plan | — | Yes |
| Free trial | — | — |
| Open source | — | — |
| Linux | Yes | Yes |
| API | — | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 0 | 1 |
| Spec score · Database Proxy Software | 7.3 (#22) | 7.8 (#9) |
| Deployment | Cetus runs only on Linux, and its installation guide describes compiling and installing it from source. | The getting-started guide provides a Docker image and lists router, admin console, and gRPC API ports as 6432, 7432, and 7000. |
| License | The repository identifies Cetus as GPL-2.0 licensed. | The source is distributed under the PostgreSQL Global Development Group License. |
| Security | The repository lists security management and client-side SSL/TLS support as features, while its usage constraints page says TLS is unsupported; the pages therefore give conflicting TLS information. | The docs show PostgreSQL connections configured with SSL modes including require and verify-full. |
| Support | The repository directs users to open an issue for bugs or feature requests and asks them to search existing issues first. | The project directs users to its Telegram chat for discussion and GitHub Issues for bug reports or feature requests. |
Plans
In their own words
SPQR
SPQR is a self-hosted query router for horizontally scaling PostgreSQL through sharding. It can extract a sharding key from a query and route it to the relevant key range and shard when possible; keys can use one column or several. Queries can also specify a key or shard in a SQL comment. Applications connect using the PostgreSQL protocol, and the router and coordinator provide administrative consoles accessible through psql. SPQR supports one-phase and two-phase commit strategies; two-phase commit provides atomicity across shards and requires max_prepared_transactions greater than zero on each shard. The system can move data between shards to balance workload, and the project describes reducing transferred ranges to limit locking impact. Its documentation includes Docker and configuration-file deployment instructions. SPQR is free and distributed under the PostgreSQL Global Development Group License. The FAQ cautions that it is not suited to complex cross-shard queries, transactions modifying multiple shards or OLAP workloads, and reports a roughly 10–30% performance drop versus vanilla PostgreSQL depending on workload.