pgloader VS docker-postgres-upgrade

No, it's difficult to read, and understand. It's a parenthesis circus, example -

https://github.com/dimitri/pgloader/blob/master/src/sources/...

Examples (for Common Lisp, so not citing Emacs): reddit v1, Google's ITA Software that powers airfare search engines (Kayak, Orbitz…), Postgres' pgloader (http://pgloader.io/), which was re-written from Python to Common Lisp, Opus Modus for music composition, the Maxima CAS, PTC 3D designer CAD software (used by big brands worldwide), Grammarly, Mirai, the 3D editor that designed Gollum's face, the ScoreCloud app that lets you whistle or play an instrument and get the music score,

but also the ACL2 theorem prover, used in the industry since the 90s, NASA's PVS provers and SPIKE scheduler used for Hubble and JWT, many companies in Quantum Computing, companies like SISCOG, who plans the transportation systems of european metropolis' underground since the 80s, Ravenpack who's into big-data analysis for financial services (they might be hiring), Keepit (https://www.keepit.com/), Pocket Change (Japan, https://www.pocket-change.jp/en/), the new Feetr in trading (https://feetr.io/, you can search HN), Airbus, Alstom, Planisware (https://planisware.com),

or also the open-source screenshotbot (https://screenshotbot.io), the Kandria game (https://kandria.com/),

and the companies in https://github.com/azzamsa/awesome-lisp-companies and on LispWorks and Allegro's Success Stories.

https://github.com/tamurashingo/reddit1.0/

http://opusmodus.com/

https://www.ptc.com/en/products/cad/3d-design

http://www.izware.com/mirai

https://apps.apple.com/us/app/scorecloud-express/id566535238

I worked on migrating our MySQL system to PostgreSQL using pgloader ( https://pgloader.io/ ).

There were some hiccups, things that needed clarification in documentation, and some additional processes that needed to be done outside of the system to get everything we need in place, it was a amazing help. Not sure the project would've been possible without it.

Data mapping from PostgreSQL to PostgreSQL as in the article isn't nearly as bad as going between systems. We took a full extended outage and didn't preload any data. There were many dry runs before hand and validation before hand, but the system wasn't so mission critical that we couldn't afford to shutoff the system for a couple of hours.

Initially, I started down the pgloader path, which seemed to be a common approach for the database conversion. However, using my M1-chip MacBook Pro led to some unexpected issues. Instead, I opted to use NMIG to convert MySQL to PostgreSQL. For more information, please check out the “Highlights From the Database Conversion” section below.

I just checked pgloader (which is mostly for heterogeneous database migrations) and it doesn't seem to have any explicit throttling features, either. However, you can set concurrency, number of workers, and batch size.

But do what makes you happy. The best PostgreSQL data loader in the world is written in Common Lisp. Now, CL is a fast and ANSI standardized language with multiple implementations, and was used to create Reddit, but it's hard to call it fashionable.

- [ScoreCloud](https://scorecloud.com/) - A web and mobile application to automatically create music notation from music performance or recordings. Built with LispWorks.

## DB tools

- [Pgloader](https://github.com/dimitri/pgloader/) - Migrate to PostgreSQL in a single command!. [PostgreSQL License]

I would warmly recommend https://pgloader.io but, unfortunately, the Oracle support is still in need of a sponsor :-)

I followed instruction here: https://github.com/dimitri/pgloader/blob/master/INSTALL.md, but can't get pass sbcl requirement.

https://pgloader.io/ There's been a great tool available for this for many years.

Ah, looks like psql seems to have switched to actually using minor and major versions properly during the last two years - I remember the dance from the 9.x versions and postgres-upgrade [1].

In any case it's way more straightforward with mysql.

[1] https://hub.docker.com/r/tianon/postgres-upgrade

Related: https://github.com/tianon/docker-postgres-upgrade

Also don't forget to pg_dump before the upgrade, as the binaries for previous Postgres version might not exist anymore after the upgrade... Otherwise, https://hub.docker.com/r/tianon/postgres-upgrade/ might be helpful (haven't used it though).

> When you say "complex ride" what does that mean?

On managed postgresql services like RDS it's easy, yes, because Amazon does all of the nasty work for you and has already seen all the kinks you may run into.

If you are on your own and using Docker, you essentially need a third-party image that has the old and new binaries (https://github.com/tianon/docker-postgres-upgrade).

If you are on your own and are using distribution packages, it's more complicated (https://blog.samuel.domains/blog/tutorials/from-stretch-to-b...).

If you are on your own and use postgres from source, well... have fun, there's a reason why I prefer using distribution-maintained packages when possible.