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PostgreSQL 11.3 and 10.8

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Re: PostgreSQL 11.3 and 10.8

#141

Post by bigato »

Macha wrote: post #77
buster wrote: post #59

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/SQL_Server Same as "FTP Server" doesn't mean proftpd, "HTTP Server" doesn't mean apache and "C compiler" doesn't mean gcc. SQL is a language. Server is a generic term. Another example: I may ask my colleague the following: "Which SQL server should we use in our new project?". Does this mean, i would like to know the edition and version of the MS SQL Server or maybe (and from my point of…

But httpd does mean Apache, and sh means Bourne shell. It also helps that nobody says "The SQL server is down" when their mysql instance is down. Even when using a generic term it's "the database is down"

In openbsd, httpd means their own webserver. In plan9, there is also a webserver called httpd.

Re: PostgreSQL 11.3 and 10.8

#142

Post by dspillett »

grouseway wrote: post #68
Keyframe wrote: post #41

Earlier quoted context omitted.

$7500 per core, but only $15,000 for two cores sounds like a sweet deal though.

There are no more server CPUs with less than 6 cores though. We could happily manage with just 2 dedicated to SQL server, but you have to license all the cores you have. So 3K worth of low end hardware ends up costing you several multiples of that in licensing.

> but you have to license all the cores you have

Is that the case? I'm sure I've seen people running on limited cores for licencing reasons rather than having to licence every core. Not sir if that was enforced by the engine refusing to use more, or via seeing processor affinities.

Re: PostgreSQL 11.3 and 10.8

#143

Post by eropple »

grouseway wrote: post #68
Keyframe wrote: post #41

Earlier quoted context omitted.

$7500 per core, but only $15,000 for two cores sounds like a sweet deal though.

There are no more server CPUs with less than 6 cores though. We could happily manage with just 2 dedicated to SQL server, but you have to license all the cores you have. So 3K worth of low end hardware ends up costing you several multiples of that in licensing.

What features in SQL Server Enterprise do you need? More than 24 cores? More than 128GB of RAM?

I ask because SQL Server Standard is significantly cheaper when you're using CALs instead of unlimited connections. Ten servers fronting a SQL Server Standard install is $3K, which at a large enterprise is often within a director-level's discretionary equipment budget.

Re: PostgreSQL 11.3 and 10.8

#144

Post by oarabbus_ »

zerocrates wrote: post #140
oarabbus_ wrote: post #134

Earlier quoted context omitted.

Please humor me if I sound a bit triggered in this response, as MySQL pre-v8.0 is like if the creators went to data analysts and asked: "what features could we remove, and what changes could we make to an SQL-standard-compliant DB (postgres), in order to slow you down as much as possible, hinder your ability to read and write queries, and generally make your life a living hell?" I really get that MySQL is good for wh…

I'm not sure what you mean by the "star from one table, specific columns from another" issue... if I'm understanding correctly I'm pretty sure MySQL allows just that. Division by zero errors and non-"magical" GROUP BY have been the default mode of operation for a _little_ longer, since the 5.7 series.

Hmm, you're right. Must've been user error on that one ;)

I stand by the rest of my points, however.

Re: PostgreSQL 11.3 and 10.8

#145

Post by CuriouslyC »

eberkund wrote: post #44

I maintain a couple of MySQL based applications. I don't really use any features outside of "standard SQL" is there a reason to switch over to Pg? I haven't used Pg before and usually default to MySQL.

- A robust security model with role inheritance that supports both column and row policies.

- PLV8/PLPython/C functions/etc (with security!)

- TimescaleDB

- Better JSON query support

- Foreign Data Wrappers

- Better window function support

- A richer extension ecosystem (IMO)

Honestly, at this point I wouldn't use MySQL unless you only care about slightly better performance for very simple queries and simpler multi-master scaling/replication. Even saying that, if you don't need that simple multi-master scaling RIGHT NOW, improvements to the Postgres multi-master scaling story are not too far off on the roadmap, so I would still choose PG in that case.

Re: PostgreSQL 11.3 and 10.8

#146

Post by CuriouslyC »

kumarvvr wrote: post #47

Question from a Python web developer. (Django mainly, exploring Flask presently) For a complex web-app, would you suggest an ORM (looking at SQLAlchemy) or a custom module with hand written queries and custom methods for conversion to python objects? My app has a lot of complex queries, joins, etc. and the data-model is most likely to change quite a bit as the app nears production. I feel using an ORM is an unnecessa…

SQL alchemy is good for fairly straightforward queries where you mainly need to do "select * from ..." and you want to pull down related rows from another table based on a foreign key in the first table as a separate query. It's also good if you have a lot of junior devs that don't know SQL and you want to encapsulate complex sql logic for them.

If you're doing anything more complex than these basic sorts of queries and subqueries, or your developers are proficient in sql, using even a very good ORM like sqlalchemy is going to be a step down.

Since you say you're doing this all yourself, and SQL is probably the most ubiquitous programming language (in terms of percentage of jobs requiring it, not total LOC) so learning opportunities there are more valuable, I would go direct.

Re: PostgreSQL 11.3 and 10.8

#147

Post by pritambaral »

Deimorz wrote: post #95
atombender wrote: post #81

Earlier quoted context omitted.

One big argument: Transactional DDL. For example: begin; alter table foos add answer int not null default 42; alter table foos drop column plumbus; update foos set name = upper(name); create table bars (t serial); drop table dingbats; rollback; // Or, of course, commit What's the benefit? Atomic migrations. You can create, alter, drop tables, update data, etc. in a single transaction, and it will either commit comple…

I use transactional DDL in my tests. All the tables, triggers, etc. are set up inside a transaction, and then the actual tests run inside nested transactions. At the end of the test run, the outer transaction gets rolled back, and everything disappears. I don't know if it accomplishes anything truly new (other than ideas that aren't very useful in practice like being able to have multiple test runs going in parallel)…

I use Pg's Template Databases[1] for this. Gives me the freedom to use transactions and concurrency in tests.

Without this built-in feature, I'd have used filesystem snapshots, if I didn't mind the time it'd take to stop and start Pg.

----

1: https://www.postgresql.org/docs/current/manage-ag-templatedb...

Re: PostgreSQL 11.3 and 10.8

#148

Post by pritambaral »

Macha wrote: post #77
buster wrote: post #59

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/SQL_Server Same as "FTP Server" doesn't mean proftpd, "HTTP Server" doesn't mean apache and "C compiler" doesn't mean gcc. SQL is a language. Server is a generic term. Another example: I may ask my colleague the following: "Which SQL server should we use in our new project?". Does this mean, i would like to know the edition and version of the MS SQL Server or maybe (and from my point of…

But httpd does mean Apache, and sh means Bourne shell. It also helps that nobody says "The SQL server is down" when their mysql instance is down. Even when using a generic term it's "the database is down"

> ... and sh means Bourne shell.

1. Except on Android, stock Debian/Ubuntu/etc., and in the bootloader and initramfs of my embedded OS;

2. I'm guessing you actually meant 'Bourne Again Shell' instead of 'Bourne Shell'.

Re: PostgreSQL 11.3 and 10.8

#149

Post by jbverschoor »

devereaux wrote: post #127
Symbiote wrote: post #28

Earlier quoted context omitted.

I upgraded from 9.3 → 11.2 a few months ago using pg_upgrade[1], on a master+slave database with 150GB of data. I did a fair amount of testing, but the final procedure was very fast and smooth. 1. Test the upgrade: set up an additional secondary (9.3), break the replication link (promote it to a master). Test the upgrade on that. It was really fast, under 30 seconds to shut down the old DB, run the in-place upgrade,…

This is a nice way to do that, but you have a low volume of data, and you think 30 seconds is fast and 1 minute of downtime is acceptable. I question these assumptions. Consider the situation when you're adding thousands of new records per seconds, and the database is being used every second (quite literally: to compute per seconds statistics). A better solution is to have triggers on the old master, to do the same i…

Not everyone is google, and hec. even google an their services are down sometimes.

If there's not too much data, it seems like the safest and fastest option.

Re: PostgreSQL 11.3 and 10.8

#150

Post by zaarn »

Macha wrote: post #77
buster wrote: post #59

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/SQL_Server Same as "FTP Server" doesn't mean proftpd, "HTTP Server" doesn't mean apache and "C compiler" doesn't mean gcc. SQL is a language. Server is a generic term. Another example: I may ask my colleague the following: "Which SQL server should we use in our new project?". Does this mean, i would like to know the edition and version of the MS SQL Server or maybe (and from my point of…

But httpd does mean Apache, and sh means Bourne shell. It also helps that nobody says "The SQL server is down" when their mysql instance is down. Even when using a generic term it's "the database is down"

sh refers to a POSIX shell. The bourne shell (bsh) is not entirely compatible with the Bourne Against Shell (bash), and bash will switch to a compatibility mode if called as sh.

Additionally, many distros, including Ubuntu and Debian, do not use bash as their default shell. (Ubuntu/Debian use dash, Arch uses zsh, Alpine uses busybox sh)

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