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I am working on a web application using Python (Django) and would like to know whether MySQL or PostgreSQL would be more suitable when deploying for production.
In one podcast Joel said that he had some problems with MySQL and the data wasn't consistent.
I would like to know whether someone had any such problems. Also when it comes to performance which can be easily tweaked?
A note to future readers: The text below was last edited in August 2008. That's nearly 11 years ago as of this edit. Software can change rapidly from version to version, so before you go choosing a DBMS based on the advice below, do some research to see if it's still accurate.
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Better?
MySQL is much more commonly provided by web hosts.
PostgreSQL is a much more mature product.
There's this discussion addressing your "better" question
Apparently, according to this web page, MySQL is fast when concurrent access levels are low, and when there are many more reads than writes. On the other hand, it exhibits low scalability with increasing loads and write/read ratios. PostgreSQL is relatively slow at low concurrency levels, but scales well with increasing load levels, while providing enough isolation between concurrent accesses to avoid slowdowns at high write/read ratios. It goes on to link to a number of performance comparisons, because these things are very... sensitive to conditions.
So if your decision factor is, "which is faster?" Then the answer is "it depends. If it really matters, test your application against both." And if you really, really care, you get in two DBAs (one who specializes in each database) and get them to tune the crap out of the databases, and then choose. It's astonishing how expensive good DBAs are; and they are worth every cent.
When it matters.
Which it probably doesn't, so just pick whichever database you like the sound of and go with it; better performance can be bought with more RAM and CPU, and more appropriate database design, and clever stored procedure tricks and so on - and all of that is cheaper and easier for random-website-X than agonizing over which to pick, MySQL or PostgreSQL, and specialist tuning from expensive DBAs.
Joel also said in that podcast that comment would come back to bite him because people would be saying that MySQL was a piece of crap - Joel couldn't get a count of rows back. The plural of anecdote is not data. He said:
MySQL is the only database I've ever programmed against in my career that has had data integrity problems, where you do queries and you get nonsense answers back, that are incorrect.
and he also said:
It's just an anecdote. And that's one of the things that frustrates me, actually, about blogging or just the Internet in general. [...] There's just a weird tendency to make anecdotes into truths and I actually as a blogger I'm starting to feel a little bit guilty about this
Just chiming in many months later.
The geographical capabilities of the two databases are very, very different. PostgreSQL has the exceptional PostGIS extension. MySQL's geographical functionality is practically zero in comparison.
If your web service has a location component, choose PostgreSQL.
I haven't used Django, but I have used both MySQL and PostgreSQL. If you'll be using your database only as a backend for Django, it doesn't matter much, because it will abstract away most of the differences. PostgreSQL is a little more scalable because it doesn't hit the brick wall as fast as MySQL as data-size/client-count increase.
The real difference comes in if you are doing a new system. Then I'd recommend PostgreSQL hands down, because it has a lot more features which make your DB layer much more customizable, so that you can fine-tune it to any requirements you might have.
Although it's a bit out of date, it would be worth reading the MySQL Gotchas page. Many of the items listed there are still true, to the best of my knowledge.
I use PostgreSQL.
I use both extensively. My choice for a particular project boils down to:
Licensing - Are you going to distribute your app (IANAL)
Existing Infrastructure and Knowledge Base
Any special sauce you have to have.
By special sauce I mean things like:
Easy/cheap replication = MySQL
Huge dataset problems with small results = PostgreSQL. Use the language extensions, and have very efficient data operations. (PL/Python, PL/TCL, PL/Perl, etc)
Interface with R Statistical Libraries = PostgreSQL PL/R available in debian/ubuntu
Well, I don't think you should be using a different database brand in anything past development (build, staging, prod) as that will come back to bite you.
From how I understand it PostgreSQL is a more 'correct' database implementation while mySQl is less correct (less compliant) but faster.
So if you are pretty much writing a CRUD application mySQL is the way to go. If you require certain features out of your database (if you're not sure then you don't) then you may want to look into postgreSQL.
If you are writing an application which may get distributed quite a bit on different servers, MySQL carries a lot of weight over PostgreSQL because of the portability. PostgreSQL is difficult to find on less than satisfactory web hosts, albeit there are a few. In most regards, PostgreSQL is slower than MySQL, especially when it comes to fine tuning in the end. All in all, I'd say to give PostgreSQL a shot for a short amount of time, that way you aren't completely avoiding it, and then make a judgement.
Thank you. I've used Django with MySQL and it's fine. Choose your database on the features you need. Hard to compare MySQL and Postgres. Better to compare Postgress to SQl Server.
#WolfmanDragon
PostgreSQL has (tiny) support for objects, but it is, by nature, a relational database. From its about page:
PostgreSQL is a powerful, open source relational database system.
MySQL is a relational database management system while PostgreSQL is an object-relational database management system. PostgreSQL is suited well for C++ or Java developers, as it gives us more control over how queries are written. ORDBMS also gives us Objects and User Defined Types. The SQL queries themselves are much closer to the ISO standards than MySQL.
Do you need an ORDBMS or a RDBMS? That will better answer your question.
Related
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Closed 10 years ago.
I guess this has been brought up many times, but I'm bringing it up again!!!
Anyway... In Ruby on Rails Sqlite3 is already setup and no extra picking and slicing is needed, but...
after numerous readings here and other places, some say it's not scalable while others say it can actually be quite good at that. Some say MySQL is much better for bigger projects, while others think, just go with PostgreSQL.
I'm interested in hearing your opinion on this. In two scenarios. One where you are starting a little website for news publishing website like CNN news, and the other scenario where you're creating a website similar to Twitter?
Highly depends on your application.
Generally spoken, any write operation into a SQLite database is slow. Even a plain :update_attribute or :create may take up to 0.5 seconds. But if your App doesn't write much (killer against SQLite: write to DB on every request!), SQlite is a solid choice for most web apps out there. It is proven to handle small to medium amounts of traffic. Also, it is a very good choice during development, since it needs zero configuration. It performs also very well in your test suite with the in-memory mode (except you have thousands of migrations, since it rebuilds from scratch every time). Also, it is mostly seamless to switch from SQLite to, eg MySQL if its performance isn't enough any longer.
MySQL is currently a rock-solid choice. Future will tell what happens to MySQL under Oracle.
PostgreSQL is the fastest one as far as I know, but I haven't used it in production yet. Maybe others can tell more.
I'd vote for Postgres, it's consistently getting better, especially performance wise if that's a concern. Taking you up on the CNN and Twitter examples, start out with as solid footing as you can. You'll be glad later on down the road.
For websites, SQLite3 will suffice and scale fine for anything up to higher middle class traffic scenarios. So, unless you start getting hit by millions of requests per hour, there's no need to worry about SQLite3's performance or scalability.
That said, SQLite3 doesn't support all those typical features that a dedicated SQL server would. Access control is limited to whatever file permissions you can set for UNIX accounts on the machine with your database file, there's no daemon to speak of and the set of built-in functions is rather small. Also, there's no stored procedures of any kind, although you could emulate those with views and triggers.
If you're worried about any of those points, you should go with PostgreSQL. MySQL has (indirectly) been bought by Oracle, and considering they also had their own database before acquiring MySQL, I wouldn't put it past them to just drop it somewhere along the line. I've also had a far smoother experience maintaining PostgreSQL in the past and - anecdotally - it always felt a bit snappier and more reliable.
DISCLAIMER:
My opinion is completely bias as I have used mysql since it first came out.
Your question brings in another argument about how your development environment should be setup. A number of individuals will argue that you should be using the same dbms in development as you do in testing/production. This is totally dependent upon what you're doing in the first place. Sqlite will work fine, on development, in most cases.
I've personally been involved with more sites using MySql and MsSql than Postgres.
I was involved in a project that scrubbed the National Do-Not-Call list against client numbers. We stored that data locally. Some area codes easily have over 5 million records. The app was initially written in .Net using MsSql. It was "not-so-fast". I changed it to use PHP and MySql (Sad says before I found out about Ruby). It would insert/digest 5 million rows in(about) 3 seconds. Which was infinitely faster than processing it through MsSql. We also stored call log data in tables that would grow to 20 million records in less than a day. MySql handled everything we threw at it like a champ. The processing naturally took a hit when we setup replication but it was such a small one that we ignored it.
It really comes down to your project and what solution fits the need of the project.
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Closed 11 years ago.
I know that both these databases are better for different scenarios but in terms of a website where users will login and enter numerical data to a daily log, which one would it be best to use? I read that mySQL is faster to begin with but PostgreSQL is more scalable if the website were to start getting a lot of users?
The downside is that my host only offers mySQL and so to use postgreSQL I would have to purchase VPS hosting which is more expensive. I have also read people advising people to not worry about it to begin with, however it concerns me that I would have to rewrite queries and forms if I later moved to postgreSQL? I would appreciate everyone's thoughts on this.
I don't understand why people have given this question negative marks when I clearly stated that I am from a finance background and only started learning 3 weeks ago. I think you need to remember that everyone has to start somewhere and that we haven't all been doing this as a job/hobby for years. I would love to see some of you come out of your comfort zone and come and do my job for a day as you would be equally as clueless and I can guarantee that I would not be so rude as some of you have been here. You should be trying to create an environment of learning and innovation, rather than an environment of arrogance. If everyone knew everything, what would be the point in this website?
Disclaimer: I have worked a lot more with PostgreSQL than with MySQL
From a performance/scalability point of view both are probably pretty much the same. There are workloads where Postgres is better and there are workloads where MySQL is better. Unless you test it in your environment it's hard to tell which one would work better for you.
Postgres seems (seemed?) to be faster in a workload with a lot of concurrent writes, whereas MySQL seems to be better with heavy read-only workload. But those benchmarks are about 3-4 years old now, so they are probably no longer true - especially since InnoDB in MySQL 5.5 improved a lot in that area.
However PostgreSQL's SQL features are far more advanced than MySQL's and MySQL has a tendency to silently ignore things you tell it to do - especially in a default installation (and if you rely on a foreign key to be created that might be a very unpleasant surprise). MySQL still has an advantage in terms of clustering as far as I can tell.
They are both equal when it comes to High Availability solutions.
I strongly disagree with the opinion that one should avoid any DBMS specific features - utilizing all features of a DBMS will make your application more scalable and will increase performance.
Traditionally MySQL wasn't known for stability and quality of their releases, but that seems to have improved since Oracle has taken over.
I still don't like MySQL's release policy where they introduce major changes and features in minor releases. The PostgreSQL dev team has a much more strict policy about what goes into a minor release. Upgrading a minor release (i.e. bugfix releases) is much less "dangerous" in PostgreSQL than it is in MySQL.
Someone once said the big difference between the PG development and MySQL is: the Postgres team first makes sure your data is safe, then it makes sure everything is working correctly, then it makes it fast. Whereas the MySQL team first makes it fast, then correct and finally stable. But that too might have changed since the Oracle takeover.
Personally I'd always prefer PostgreSQL over MySQL because of the much better SQL feature set and the overall quality of the product.
MySQL is the more popular solution and is used by very large companies for very large databases, so MySQL is far from unscalable.
If you want the ability to move between both databases at a later date in case you decide to switch, I would recommend using an ORM (Look at http://www.doctrine-project.org/); this way you'll only have to write the queries once and if you change to a different database down the road, you only need to change a config variable. Doctrine will also have you build your database structure in a YAML file which it can convert for you as well.
It's also capable of migrating between database types.
You'll also want to take into account the different MySQL Engines which perform differently as well. I was just looking at a comparison between PostgreSQL and MySQL which in their conclusion, they didn't like the fact that MySQL wasn't built with transactions, however, InnoDB does provide transactional support for MySQL as well as speed and memory improvements in some cases.
So the bottom line is this: If you can make your application in such a way that you can use either database (as mentioned above) run your own benchmarks against your application and your databases and see what kind of a difference it makes to you.
There's certainly other things to think about if you have the budget for it and that's getting DBA's specific to the database you're using and get them to optimize it.
First, SQL is SQL, be sure that you use strict SQL, then you don't rewrite anything. The different between the both dbs is the level of SQL support. PosgreSQL has better support, but the support by MySQL depends on the used storage engine.
Yes, you can better scale your application with PostgeSQL, but how mach load have you on your server? 1GB per day, less more?
EDIT: I've learnt, and it's probably true that YouTube uses MySQL. But it probably would be the enterprise edition and not free edition. The only alternative seems to be PostgreSQL. Long question short - - Can PostgreSQL used instead of MySQL? Is it a very good alternative in any case?
Firstly, I noticed that these are the most common names when it comes to (relational) database management systems - - DB2 (IBM), Oracle Database, Microsoft SQL, Ingres, MySQL, PostgreSQL and FireBird. So, should I presume these are the best?
Okay, of the above - - DB2 (IBM), Oracle Database and Microsoft SQL, the so-called Enterprise DBMSs, come with a bill; while MySQL (exclude enterprise version), PostgreSQL and FireBird are open source and free.
As should be clear from my previous questions here, I plan to build a photo-sharing site (something like Flickr, Picasa), and like any other, it's going to be database-heavy and (hopefully) busy.
Here's what I would love to know: (1) does any one of the free DBMSs stand up to the mark with the paid enterprise DBMSs? (2) Can any of the free DBMSs scale and perform well for enormous and busy databases without too much headbanging and facepalming?
Things in my mind w.r.t the DB:
Mature
Fast
Perform great/fine under heavy load
Perform great/fine as database grows
Scalable (smooth transition)
support for languages (preferably Python, PHP, JS, C++)
Feature-rich
etc (whatever I am missing)
PLZ NOTE: I know Facebook, Twitter etc use (or at least used) MySQL, and I see reports from time to time, how their sysadmins cry over that decision. So, please don't say, XXX uses it, so why can't you. They've started small, I am too. They've made mistakes, I don't want to. I want to keep the scaling-transition smooth. I hope I am not asking too much. Thanks.
"Which is the best database" is a huge question and is the subject of much contention. I've noticed on StackOverflow there is a tendency to close such questions; although the question is interesting, it is also quite unresolvable ;-)
FWIW, I would go with this:
Use what you know
If it doesn't conflict too heavily with the first rule, use something that is free of charge
Use what works with other parts of your stack
Use what you can hire for at reasonable cost (so, maybe not Oracle unless you really have to)
Don't optimise too early. Working slowly is much better than an unfinished, efficient website.
Also, scalability is not really to do with your db platform, but to do with how you design your site. Note also that some platforms scale better when adding more servers (MySQL) and others do better when increasing your server resources (PostgreSQL).
Please note as of today, MySql is not a free project aka as free as postgresql. One of the main reason why i had to switch over to PG. (Thankx to NPGSQL and PgAdmin III, it was a lot easier than it was rumoured)
However MySql does have number of advantages related to applications,addons,forums and looked good on resume.
PostgreSql is a much mature DBMS. It is a objectRDBMS. It has been around for more than 15 years. It is not known to have defaulted on any major issues. It is well known to handle transactions running in millions of rows successfully. The most important is, it's high rate of compliance with SQL standards. Infact in professional circles, it is more of an Oracle of Free RDBMS rather than MySql of popular applications.
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What's the limitation?
Is there a specific volume of data each can handle regardless of disk space?
When to use what assuming licensing is not a problem?
This is a very nuanced question that really cannot be easily answered, as each situation can provide many pluses and minuses. Also, MySQL being owned by Oracle now and several branches off of the main functionality means that MySQL != MySQL anymore.
If you are looking for really really big data sets, then you will like have to break with the RDBMS sets and start to look at things like MapReduce and other large data set processing technologies.
I have personally worked with all three over the past decade or so from the application perspective. They all have their advantages, like MSSQL working will with the other Microsoft technologies like LINQ where as MySQL having a large open community support and Oracle being the workhorse of the commercial sector with lots of ability to embed application logic right into the database.
Again, it really depends on the application, the situation, the skills of the people who will maintain it after it is developed, commercial considerations, hardware and platform considerations, etc etc etc.
It depends what you are trying to do and obviously it has to do with cost.
MySQL and Postgres are very widely used by a huge number of startups because its open source and there is a lot of support out there for people using it
MSSQL is good if you are using MS programming languages because of the ease to connect and use.
I have never used oracle but know people use it a lot for data warehouseing so can't have that much of a bad name
All of these will suffer from similar issues when scaling because they are RDBMS databases. They do also have decent ways to get round it and with a decent ORM used in your code then it shouldn't matter what you use.
Pick the one that all the developers are comfortable with
I'd say if you want to compare apples to apples, then it is MySQL vs SQL Express, vs Oracle Express.
Or if you have $, then it is the MySQL support license, MS-SQL Standard, vs whatever Oracle's cheapest offering is.
In my experience, once you choose a language, e.g. Php goes best with MySQL, then you've chosen your DB. Java goes well with Oracle. C# goes well with MSSQL.
Similarly, if you choose your OS, then unix flavors run MySQL or Oracle, but MSSQL is windows only. MySQL and Oracle work on both unix and windows of course.
If you need to buy many machines, then not having to pay OS licenses for the server helps in scaling.
As to skaffman's point you may want to have a look at postgres if mysql isn't scaling for you. It is a more mature and robust than mysql and is opensource. The time to make the switch is highly dependent on you application environment, however, if you need clustering and replication to work properly 100% of the time then postgres will not let you down (as mysql has for me in the past)
It would help narrow things a great deal if you'd provide details like whether or not you intend to distribute the database along with your software; your system will be hosted; how much data; etc.
Don't assume anything with regard to licensing. Get a lawyer, maybe even one who specializes in open source law.
"...regardless of disk space..." - capacity always depends on this. Where do you think the data goes? Better to think about things like sharding your data, RAID, clustering, replication, etc.
I would worry about any system whose developer had to come to a forum like this to ask that kind of question. You should have people on staff with sufficient skill and knowledge to have a strong opinion on this sort of thing.
Perhaps one variable which people overlook in these cases is the availability of expert support. Okay, so currently there's an oversupply of people who can help you with db issues, efficiency issues, disaster recovery etc. However this may not be always the case in the future, and it's the applications you use it for that may be the defining issue. Are there people in your organization who have experience in one or more of the relevant databases? (as it happens I believe that someone's who's become proficient in say Oracle, can become fairly competent in Sql*Server or Mysql in a fairly short space of time) You state it's going to be used for your financial systems - perhaps you really need input from a consultant who's worked on implementing and/or supporting financial systems - for example I understand that Sybase is popular in City type firms. Or perhaps there's an off-the-shelf package that utilises a preferred database? Try and define exactly what your system(s) needs to do first.
Is the application buy or build ?
If Buy, does it support all three and
talk to the app vendor about the
differences ?
If Build, then is it an in-house
build or contract out. If contracting
out, put out your requirements and
let the suppliers put their
arguments.
If in house build, then first look at
why you are not contracting out.
Normally it is because you already
have an in house capability, so look
at that expertise.
You want some sizing information first.
Are you talking data volumes in megabytes, gigabytes or terabytes ?
What are your uptime requirements, backup (recovery time / recovery point) ?
How much concurrent activity ? Is that peak ?
Generally any database system is fine for data storage and retrieval. High-end analysis, load balancing, replication, management, backup/recovery, auditability, security are all areas you may need to consider.
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Closed 11 years ago.
Am not sure if this question makes sense. But I know all the basic CRUD commands of mysql. Probably a bit more here and there (foreign keys etc). But there are so many books written on mysql/dbms. I can write decent queries and get all my results as I want them. Maybe they aren't the most efficient but it worksforme. Thats because my apps arent facebook as yet that I have to worry about optimization. Or do I?
Am I missing the point here? What else should I know?
Thank you very much.
Premature optimization is the root of all evil. Focus on designing proper and logical database structures and indexing them correctly, that will take you far. Modifying a badly written query is always easier than modifying a badly designed database structure.
In my opinion, use the queries you have and optimize them when there is a need for optimization. What comes to the queries, rather focus on making them secure (see sql injection).
What else should I know?
Greater understanding of relational theory, so you write better SQL. I'm currently enjoying "SQL and Relational Theory," a new book by C. J. Date, the world's leading expert on the relational model.
Implementing and monitoring security - SQL injection certainly, but other issues covered by OWASP, SANS.org, or books like "19 Deadly Sins of Software Security." This is a broad topic not specific to SQL, but I think it's every software developer's duty to learn this stuff.
Performance measurement and monitoring - how will you know when you reach the point where you do need to learn optimization techniques?
I18N, L10N, character sets.
Database maintenance and recovery - backups, repair.
Replication, clustering, and proxying.
Deployment and upgrade techniques - how to apply changes to a running application or site without interrupting service.
Writing more-or-less portable SQL that works with multiple RDBMS brands. At least understand what needs to be rewritten if you need to support another brand.
How and when to employ Object-Relational Mapping frameworks.
How and when to employ non-relational databases. SQL is the best general-purpose data management paradigm, but there are other technologies more specialized to specific tasks.
Advanced MySQL is probably not just about writing queries for CRUD operations. Sometimes you need to do optimizations or various maintenance procedures that do require an intimate knowledge of the DBMS you are working with. You might not be worried about the performance of your queries and the robustness and efficiency of your database design if you deal with small to medium sized applications, but for a highly scalable application all these are factors that you have to take into account.
It's good to know CRUD syntax well. I would recommend that you go beyond that to understand relational design, primary and candidate keys, indexing, etc. These are topics that are meaningful for all relational databases, not just MySQL.
Databases are much more than just "Places to put stuff". Once you realize that, you will start using them to their full potential.
You should worry about optimization anyway imho. Sure if right now you have only 10 people who are using your application it's not the issue, but in the future if the user base grows it can really be a "pain in the ass" to rewrite database structure, especialy if in your code you are using the raw queries without database abstraction.
If you know enough to to do what needs to be done, then you know enough for now. However, Introduction to Database Systems by C.J. Date is an outstanding discussion of relational databases written by a pioneer in the field (as well as other types of database systems).
Generally, there are tons of features of mysql and other RDBMS systems that people aren't aware of. This is fine since you can get by well with a subset of features, but to deal with difficult problems or to be a good DBA there's a huge amount of stuff to learn. When people talk about Advanced X on databases, these are the types of things that are meant.
To answer your question, it's never a bad idea to find out what other features and tools are out there. You may find much better ways of solving your own problems and develop a better set of skills for solving other people's problems. I also fully agree with the other answers suggesting that you improve your knowledge on higher level topics, knowing how to make good db designs is extremely important.
Oh, now I get it (the question). I thought you meant "What is the point of combining 'Advanced' and 'MySQL'?". :-)
If you MUST use MySQL for your job, then yes, you had better gradually get a deeper understanding of it, especially what the shortcomings and gotchas are, and how other people at work may make assumptions about things that are not really going to work out.
Now, my "troll": if this is just you, use something a bit more robust. I'm no MicroSoft fan, but they do make the startup costs for using SQL Server pretty low, assuming you are working on Windows. Better yet, if you are working on a *nix server, you might try PostgreSQL. They have been pretty serious about correctly implementing quaint little things like ROLLBACK, transaction isolation, foreign key referential integrity, views, functions (aka stored procedures) for quite a few years. MySQL has improved over the years, but is still (IMHO) somewhat immature. My impression of it back around 2000 was "the reliability of xBASE with the ease of the SQL interface". (I'm not a big fan of the SQL language itself -- maybe I'm just too old to really warm up to it as the "the only possible way to do it")
I avoid MySQL like a bad flu bug, but I can add some insight here.
One area that would be covered in the "advanced" portion of MySQL is customization.
There is alot involved with SQL in general that MySQL doesn't do out of the box, or can be customized. Our company uses full stored procedure implementation and geospatial queries as two examples.
Advanced would involved good customization skills, and experience adding and working with customizations or add-ins. Anything to make MySQL be more enterprise like.