The lifecycle of a sharded Postgres query

Key takeaways

• A query router acts as the primary entry point, parsing SQL to determine which specific shards hold the required data.
• Logical queries are translated into physical queries that target one or more of the four Postgres shard instances.
• The system executes queries in parallel across shards to achieve horizontal scalability and improve response times.
• The router is responsible for aggregating, sorting, and joining partial results from shards before returning the final dataset.
• This architecture allows Postgres to handle datasets and transaction volumes that exceed the capacity of a single node.