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Why doesn't Quora use PostgreSQL

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Re: Why doesn't Quora use PostgreSQL

#41

Post by masklinn »

masklinn wrote: post #25
Empact wrote: post #9

A few bugs/limitations of Mysql not shared by Postgres. All AFAIK. * Integer columns with null constraints will silently translate nulls to 0s, rather than throwing an error (as constraints in all other contexts do). Imagine a database which, on violation of a foreign key constraint, just silently picked the first row in the target table - it's just insane. * Transactions can't roll back schema changes, so if you hav…

> Transactions can't roll back schema changes That's a feature of postgres rather than a limitation of mysql however. As far as I know the SQL Standard doesn't ask for transactional DDL, Oracle has pretty much no support for transactional DDL (in 10g anyway, each DDL statement is executed in its own transaction and any pending transaction is COMMITted before a DDL), I have no idea about SQL Server.

(and don't get me wrong, it's a totally awesome feature and it should be praised to high heaven, but it's an additional feature nonetheless, rather than a limitation of the concurrence)

Re: Why doesn't Quora use PostgreSQL

#42

Post by gaius »

scg wrote: post #19

It's interesting to see how PostgresSQL didn't get nowhere near the popularity of MySQL. I think a few major things contributed to this: 1) MySQL focused on performance first while PostgresSQL positioned themselves as "feature-complete." Of course, that was years ago and in the meantime they became comparable in both aspects. MySQL+InnoDB is ACID compliant and Postgres matches the InnoDB performance. Sure, Postgres m…

Most of MySQL's momentum I'd say would be because Slashdot used it. Because of course, a database that is (only) suitable for a scenario where reads outnumber writes a few thousand to one, and a comment getting lost is actually no big deal is obviously suitable for your OLTP app...

Re: Why doesn't Quora use PostgreSQL

#43

Post by rimantas »

pilif wrote: post #34

Ok. Being borderline trollish here, but if I read this article, this means to me "yeah. we are using a technically inferior solution and thus risking data loss and increasing the workload on our developers because our HR department gets more resumes if we search for an in-house database specialist". Postgres usually does its thing and does it well. You usually don't get weirdness that requires you to even hire a spec…

  I'm glad I migrated that huge application from MySQL to
  Postgres back in 2000. I'm glad I did not touch MySQL for
  serious stuff ever since then.
You should refrain from commenting on MySQL then. It's amazing (and sad) how many pro-PG-anti-MySQL folks don't even know basic things about MySQL but feel entitled to rant and call it "toy DB", "not real RDBMS", etc.

Re: Why doesn't Quora use PostgreSQL

#44

Post by niklas »

146 wrote: post #14
tdavis wrote: post #6

This is a common mistake people make, I think. Just because an ecosystem is smaller does not mean it is inferior (or less practical). In fact, the opposite is routinely true. Is it harder to find tutorials for PostgreSQL? Yeah, maybe. Is it harder to get high-quality advice and resources from subject matter experts? No; in fact, it's far easier. I have used PostgreSQL for many years and in all of them every question…

That's really interesting to know, actually. I've only been with companies that had MySQL installations (Facebook and Twitter) and so jumping in was really easy, but on the other hand I do like to do things right. A few questions, though: 0/ How would I be able to tell if the limitations of our DB are because of MySQL and would be solved by PostgreSQL? That is, common pain points in MySQL that we wouldn't recognize i…

re 2: The mailing lists http://www.postgresql.org/community/lists/ are a good place to ask questions. Core devs are frequently answering questions there.

Re: Why doesn't Quora use PostgreSQL

#46

Post by jasonkester »

bdr wrote: post #8
tdavis wrote: post #6

This is a common mistake people make, I think. Just because an ecosystem is smaller does not mean it is inferior (or less practical). In fact, the opposite is routinely true. Is it harder to find tutorials for PostgreSQL? Yeah, maybe. Is it harder to get high-quality advice and resources from subject matter experts? No; in fact, it's far easier. I have used PostgreSQL for many years and in all of them every question…

Seconding #postgres as awesomely smart and helpful. Especially RhodiumToad, who always seems to be in there.

I see this #whatever notation a lot. What does it refer to?

Re: Why doesn't Quora use PostgreSQL

#47

Post by rubyrescue »

jasonkester wrote: post #46
bdr wrote: post #8

Earlier quoted context omitted.

Seconding #postgres as awesomely smart and helpful. Especially RhodiumToad, who always seems to be in there.

I see this #whatever notation a lot. What does it refer to?

irc chat, generally on the 'freenode' irc server - http://freenode.net/

Re: Why doesn't Quora use PostgreSQL

#48

Post by cdr »

jasonkester wrote: post #46
bdr wrote: post #8

Earlier quoted context omitted.

Seconding #postgres as awesomely smart and helpful. Especially RhodiumToad, who always seems to be in there.

I see this #whatever notation a lot. What does it refer to?

#whatever in the context of a 'channel' means IRC (Internet Relay Chat), generally on the Freenode.net network.

Re: Why doesn't Quora use PostgreSQL

#49

Post by jasonkester »

rubyrescue wrote: post #47
jasonkester wrote: post #46

Earlier quoted context omitted.

I see this #whatever notation a lot. What does it refer to?

irc chat, generally on the 'freenode' irc server - http://freenode.net/

Wow, really? Chat? In 2010??? That would never have occurred to me. Thanks!

Re: Why doesn't Quora use PostgreSQL

#50

Post by pilif »

rimantas wrote: post #43
pilif wrote: post #34

Ok. Being borderline trollish here, but if I read this article, this means to me "yeah. we are using a technically inferior solution and thus risking data loss and increasing the workload on our developers because our HR department gets more resumes if we search for an in-house database specialist". Postgres usually does its thing and does it well. You usually don't get weirdness that requires you to even hire a spec…

I'm glad I migrated that huge application from MySQL to Postgres back in 2000. I'm glad I did not touch MySQL for serious stuff ever since then. You should refrain from commenting on MySQL then. It's amazing (and sad) how many pro-PG-anti-MySQL folks don't even know basic things about MySQL but feel entitled to rant and call it "toy DB", "not real RDBMS", etc.

note the emphasis on "serious stuff".

I did in fact touch MySQL since then in the process of setting up various open source applications that require MySQL.

While back then, I needed Postgres for some features MySQL didn't have but otherwise didn't really dislike MySQL, over those 10 years, I really learned to hate MySQL:

- try (erroneously) adding or inserting latin1-data into a UTF-8 table. You'd expect an error message, but instead your data gets truncated at the first byte with the high bit set. No warning. This means that you have to re-read and compare whatever data you stored to be sure that you didn't lose any.

- once, mysqldump stopped dumping after coming across a corrupt table. It did so while still exiting with a 0 exit code. That meant that for months my backups were incomplete.

- "alter table sometable add somcolumn integer not null" will gladly add the column and place null values in each row. Null values that should absolutely not be there. No error. No warning.

- Same goes for date columns, but there it's even better as it'll set the date to 0000-00-00 which is invalid if you try to add this in an insert or update.

- I said "corrupt table" earlier. Yeah. That happens with MySQL, whereas it never ever (with the exception of faulty hardware of course) happens with any other RDBMS - including PostgreSQL.

Now, in my opinion, a database that doesn't guarantee that the data you put in can then be read back out in unaltered form (or at all) is, really, no real RDBMS.

Sorry.

(edit: reason for not posting this in my original reply: I'm basically repeating above points over and over here on HN and I thought people would know my gripes by now)

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