Postgres without SQL: Natural language queries using GPT-3 & Rust | Citus Con: An Event for Postgres 2023 | Jelte Fennema

Slides from a conference talk about Generative AI and a new Postgres extension which allows you to use the power of GPT-3 right from your database. Presented by Jelte Fennema at Citus Con: An Event for Postgres 2023, this new PG extension makes it easy to optimize your database schema, query your data, and even distribute your Postgres tables using the open source Citus database extension. All of this by using normal human language, and without the need to know any SQL. Now you can finally jump on the NoSQL bandwagon while still using the much-loved PostgreSQL relational database.

This talk includes a section on how to write Postgres extensions using Rust (no Rust experience required.)

Transcript

1. Postgres without SQL:
   Natural language queries
   using GPT-3 & Rust
   Jelte Fennema
   Senior Software Engineer @ Microsoft
   Developing Citus, PostgreSQL, & PgBouncer
   @JelteF | @citusdata | @AzureCosmosDB
   2023-04-18
   

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2. My secret problem
   I find it very difficult to write
   working Postgres queries
   

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3. Solution
   I asked this question at: https://chat.openai.com/
   

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5. My not so secret problem
   • I don’t like doing boring things
   • Copy pasting schemas and queries
   around sounds pretty boring
   

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6. How to avoid boring stuff
   • Postgres has all this information
   • Can I tell Postgres talk to ChatGPT directly?
   • I would need to add some functionality to Postgres
   

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7. Postgres extension to the rescue
   • Allows adding new functionality to
   Postgres such as types or
   functions
   • Part 1: A shared library that
   postgres loads (.so file)
   • Part 2: Some SQL definitions, e.g.
   function definitions
   • So, let’s write an extension!
   

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8. I like Rust
   • It feels modern: everything is an expression + pattern matching
   • Its type system is fancy: Like Haskell but I can read it
   • Secure: No memory leaks, no double frees, no data races
   • It’s as fast as C/C++
   • It has a package manager
   Rust logo by Rust Foundation, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=40715219
   

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9. I have been playing with Rust for a long time
   • I have a popular Rust library: derive_more
   • It automates writing boring boilerplate
   • 7 years old
   

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10. But I never used Rust professionally
    • So, let’s change that!
    • How do I combine Postgres and Rust? And maybe even Citus?
    

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11. Let’s go write a Postgres extension in Rust
    

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12. Setup is extremely easy
    • Install pgx, also installs 5 postgres versions:
    • Create a new extension:
    

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13. Oh no, we need a name for this extension
    • pg_gpt is the obvious choice but is already taken 
    https://github.com/cloudquery/pg_gpt
    • gptpg: palyndromes are awesome but is hard to pronounce
    • Final choice: pg_human
    

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14. Just double checking
    

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15. Setup continued
    • Create the new extension
    

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16. Has built in Hello World
    

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17. So let’s make some small changes
    • What? Why does it take 7 seconds to compile this tiny extension?
    

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18. GNU linker (gold) is really slow
    

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19. But mold is fast
    

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20. Okay now can actually start. What do we need?
    • Getting the schema definition
    • Sending requests to the OpenAI GPT API
    • Executing SQL
    • Returning arbitrary SQL results
    

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21. Getting the schema definition
    • Ugh, why doesn’t Postgres have a built-in function for this?
    • Fine I’ll fetch stuff from the catalog tables myself and concatenate some strings
    

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22. Sending requests to the GPT API
    • Use the Rust package manager to get an API client
    

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23. Sending requests to the GPT API
    • Give the AI some confidence
    

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24. Sending requests to the GPT API
    • Tell it what you have
    • Tell it what you need
    • Tell it what you do not want
    

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25. Sending requests
    • Rust loves async and threads
    • Async support in pgx is non-existent
    • Postgres and pgx don’t like threads
    

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26. Executing SQL
    • Postgres has SPI
    (Server Programming Interface)
    • pgx has nice Rust bindings for SPI
    

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27. Returning arbitrary results
    • Another problem: Postgres requires functions to have known columns
    • Let’s go fully NoSQL and just return a single json column
    

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28. Demo time
    

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29. Where to find this amazing Postgres extension
    https://github.com/JelteF/pg_human (USE AT YOUR OWN RISK)
    

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30. Future ideas
    • Explaining explain plans
    • Index suggestions
    • Citus distribution column suggestions
    

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31. Any questions?
    

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32. Resources
    

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