> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify-poc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Limitations

> TimescaleDB features come with a few limitations that we are constantly working to remove. See the current and regularly updated list of limitations

export const PG = 'Postgres';

export const TIMESCALE_DB = 'TimescaleDB';

While {TIMESCALE_DB} generally offers capabilities that go beyond what {PG} offers, there are some limitations to using hypertables.

## Hypertable limitations

* Time dimensions (columns) used for partitioning cannot have NULL values.
* Unique indexes must include all columns that are partitioning dimensions.
* `UPDATE` statements that move values between partitions (chunks) are not supported. This includes upserts (`INSERT ... ON CONFLICT UPDATE`).
* Foreign key constraints from a hypertable referencing another hypertable are not supported.