If you're fighting the attitude that the only viable option is one that costs a ton of money instead of a decision based on technical merit, additional facts about Postgres won't help.
Sometimes the decision gets made on a golf course and not after reading very long texts.
This is why I swore to only write software at software companies some years ago. For other industries software is just another expense like buildings or supplies. The people buying it have no idea what they're looking at so they buy the shiny thing that everyone else is buying.
When I worked in other sectors I regularly saw executives attempt to assemble software as if it was a large building. Materials were gathered, agreements were made to purchase or rent heavy equipment, and the whole project was planned out with exacting detail. When all the permits and contracts were in place construction would begin. This was to be done in a measured amount of code using the chosen architecture, and delivered complete on a certain date. Any deviations were seen as workarounds for not following the original plans, and overruns the result of incompetence. The whole thing was just a shitshow of incompetence at the higher levels.
Demanding and exercising the use of a throat to choke is a massive, massive part of how at least American business works due to prevailing leadership styles as well. It also shows how they tend to view their workers as well. "Blameless culture" is something that is a tiny, tiny minority that only seems to have worked out well among socialist-ish boutique software companies and until we start seeing companies that practice traditional Taylorist and authoritarian leader worship cultures fail very disproportionately, nothing will fundamentally change.
I'm familiar with a number of very large deals done basically between C-level to C-level where the scope of IT projects has nothing to do with technologies but entire about cost savings - literally "I will save you $n MM / yr in opex so you can get your bonuses" and other vendors get shut out. Sometimes these deals work out, other times they don't and the executive is basically ousted. Companies with bad politics and enormous cronyism may have worked fine for decades, but they just may not be doing as well anymore unless you're on Wall Street and you make so much money it doesn't matter how it's done.
Software is not the end-goal itself. The point is not to make (or use) amazingly elegant software. The point is to make money.
If a supplier says "I will provide the same service as you are currently getting and cost you $X less" then that's a no-brainer regardless of what service they're providing. It's got nothing to do with technology, and technology doesn't change the nature of that decision.
"Having a throat to choke" is also a matter of insurance. You can't insure against your own incompetence, but you can sue a supplier for not fulfilling the terms of their contract. Executives would much rather negotiate what they think is a tough contract with a supplier than manage a complex project themselves. To that mindset, the removal of risk (because if anything goes wrong they can sue the supplier) is a huge bonus.
It's a totally different mindset from those of us who actually make things.
I was a Sybase point person for years at a fortune 50 medical devices enterprise company (we had revenues of well over $1B annually on devices running Sybase dbs). There were dozens of bugs/issues I found that I pushed up the chain to an engineer and had special patches turned around within 48 hours, sometimes even hours.
Before I left that job I started playing around with Rails and mentioned MySQL and Postgres for a potential greenfield project. I was told it would be fine for internal use but no way, no how were they going to deploy any software without that kind of parachute based on economic leverage.
Often enough you'll even get similar turn-around times from the community, if you can't (or don't want to) afford such a support contract.
Making software work at scale without that economic leverage could never work in theory. It only works in practice.
Oh, and those who did it were above oracle in terms of data size making it rational decision too. The calculation is still different for majority of companies.
Specifically, I've seen pg take a query that looks like this:
select ... from a join b join c join (select ...) d
select ... from (select ...) d join a join b join c
With the lack of hints, almost the only tool you have to control query plans effectively in postgres is parenthesized joins. Since it's more liable to rewrite the query, the language ends up being less imperative, and thus less predictable. And I like predictability in production.
SQL-level feature set is no comparison of course, pg wins easily.
I'd also suggest disabling nest_loop_entirely if you are having problems with bad cardinality estimates resulting in nestloop plans that run 100 times when the planner estimated once.
It is interesting to see how postgresql will often choose hashmap scan, even with very up to date statistics and much better paths available.
SQLServer's planner does an amazing job of digging right into joins/sub-selects to constrain preliminary results for joins.
It's a very hard job and MS and Oracle obviously have had some of the best people on the world paid well to work on this.
The company for the longest time wouldn't even touch basic firewall rules without having the firewall contractor implement it.
Many also think looking up issues on stackoverflow, google or blogs as unreliable. Then there are times when issues might be specific to installs or data, in which case sharing the logs/sample data (even masked ones) can be risky. They feel comfortable sharing logs/masked data with for example Oracle because they believe it to be safe and locked under Oracle's security guidelines.
The 2nd refrain I hear is - security. In case of a major security issue being revealed, there is a general sense that FOSS will be slower to react in releasing a
"stable" patch. Comparatively paid software take it as a reputation risk and work towards quickly releasing a "stable" patch.
If people have to use FOSS, then they try and search for the paid support flavor. Recently we were looking at MQ software. When we zeroed in on RabbitMQ we were asked to deploy only the paid Pivotal version and not the free version because "support".
Sure, these things might not be completely true but for many higher ups paying for something somehow makes them sleep better at night than a "free" alternative.
> Written for longevity
OSS is much better at longevity than proprietary. Even if the authors all die without will, it is possible to fix the little bugs that prevent you from using the software on [NewTechnologyHere]. I've done it countless times with Java software; If anything OSS is the guarantee that you own your future and that the system will exist in the legacy.
> Use paid flavor
It's good, but what's better is joining the golf club of a principal maintainer. He's key in paying him to fix the issue you're having quickly and merging upstream.
Long, long ago when I worked at Nortel (a now defunct, but then huge telecommunications company), they used to pay millions of dollars a year to Cygnus to support a particular embedded version of GCC. This, despite the fact that Nortel had more than 10k programmers on staff including a compiler team!
I think the real reason these support contracts exist is because companies (even large ones) don't want to dilute their focus maintaining projects that are peripheral to their core business. It's not so much a technical problem, or a money problem -- it's a management problem. They can't scale out to handle every little thing.
I think OSS is a red herring in this conversation. Most companies just don't care about that. They don't want to support it themselves (even if they are big enough to do so), and they need to have confidence in the company that provides the support. Build that company (hint: you need to be sales heavy!) and you could sell Postgresql just as easily as any other database. Of course breaking into an entrenched area in Enterprise software is always going to be difficult, so I'm not sure how successful you would be with this particular product, but you get my point, I think.
As hindsightbias puts it they want solutions and 24*7 support.
I think is the better point or rewording of your point.
Let me rather call it, The Real World.
I work in a Fortune 500 company, a consultancy of 400.000 people, on projects for other Fortune 500 companies.
My experience is from the real world.