This PostgreSQL extension implements t-digest, a data structure for on-line accumulation of rank-based statistics such as quantiles and trimmed means. The algorithm is also very friendly to parallel programs.

This extensions tracks WHERE clauses predicates and JOIN predicates. Statistics will report whether the predicate was evaluated as an index scan or not, how many time the expression appeared, how many times the operator was executed and how filtering the expression is. If pg_stat_statements is enabled, it can also track to which statements the predicate belongs.

The pg_dirtyread extension provides the ability to read dead but unvacuumed rows from a PostgreSQL relation.

pg_partman is a PostgreSQL extension to create and manage both time-based and serial-based table partition sets. Sub-partitioning is also supported. Child table & trigger function creation is all managed by the extension itself. Tables with existing data can also have their data partitioned in easily managed smaller batches. Optional retention policy can automatically drop partitions no longer needed. A background worker (BGW) process is included to automatically run partition maintenance without the need of an external scheduler (cron, etc) in most cases.

mbedtls is an open source library that implements lightweight and efficient solutions for security protocols, including TLS (widely used in security between network communications)

Primarily it provides an automatic dispatch mechanism that means you can write backend agnostic code that works for numpy, pytorch, jax, cupy, dask, autograd, tensorflow, sparse, mars, etc., and indeed any library that provides a numpy-ish API, even if it knows nothing about autoray.