At the current pace of media content creation, Reddit expects their media metadata to be roughly 50 terabytes. This means they need to implement sharding and partition their tables across multiple Postgres instances.

Reddit shards their tables based on post_id where they use range-based partitioning. All posts with a post_id in a certain range will ... See more

1. The number of partitions is fixed at the time of the index creation. Each partition is an indivisible chunk of data which can grow in size but not be split into smaller chunks. As the data grows, more nodes may be added to the cluster, but the number of partitions which eventually move to the newer nodes are limited (Fig 3)


2. In some sense, as the da

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