Stories
Slash Boxes
Comments

News for nerds, stuff that matters

Slashdot Log In

Log In

Create Account  |  Retrieve Password

PostgreSQL vs. MySQL comparison

Posted by Hemos on Mon Dec 18, 2006 09:25 AM
from the get-the-morning-starter dept.
prostoalex writes "Ever find yourself wondering which open source database is the best tool for the job? Well, wonder no more, and let your tax dollars do the work in the form of Fermi National Accelerator Laboratory publishing this unbiased review of MySQL vs. PostgreSQL. After reading it, however, it seems that MySQL ranks the same or better on most of the accounts." My poor sleepy eyes misread the date of posting on here; caveat that this is more then 15 months old.
+ -
story

Related Stories

[+] News: Pro MySQL 100 comments
Rob Lanphier writes "I'm sure there are plenty of people like myself who do a fair amount of programming against MySQL databases, and consider it a feature of the product that it's pretty easy to do without having to fuss much with the actual database. Still, it's nice to look at what goes on under the hood, even if smoke isn't pouring out from beneath it. Pro MySQL by Michael Kruckenberg and Jay Pipes provides a broad well-organized exploration of intermediate and advanced MySQL topics that is a satisfying overview of the database management system." Read the rest of Rob's review.
[+] PostgreSQL Slammed by PHP Creator 527 comments
leifbk writes "'The Web is broken and it's all your fault' says Rasmus Lerdorf, the creator of PHP. He talks about not trusting user input, and the brokenness of IE, which is all fine. Then he makes a statement about MySQL vs PostgreSQL: 'If you can fit your problem into what MySQL can handle it's very fast,' Lerdorf said. 'You can gain quite a bit of performance.' For the items that MySQL doesn't handle as well as PostgreSQL, Lerdorf noted that some features can be emulated in PHP itself, and you still end up with a net performance boost. Naturally, the PostgreSQL community is rather unimpressed. One of the more amusing replies: 'I wasn't able to find anything the article worth discussing. If you give up A, C, I, and D, of course you get better performance- just like you can get better performance from a wheel-less Yugo if you slide it down a luge track.'"
[+] MySQL Quietly Drops Support For Debian Linux [UPDATED] 339 comments
volts writes "MySQL quietly deprecated support for most Linux distributions on October 16, when its 'MySQL Network' support plan was replaced by 'MySQL Enterprise.' MySQL now supports only two Linux distributions — Red Hat Enterprise Linux and SUSE Linux Enterprise Server. We learned of this when MySQL declined to sell us support for some new Debian-based servers. Our sales rep 'found out from engineering that the current Enterprise offering is no longer supported on Debian OS.' We were told that 'Generic Linux' in MySQL's list of supported platforms means 'generic versions of the implementations listed above'; not support for Linux in general." Update: 12/13 20:52 GMT by J : MySQL AB's Director of Architecture (and former Slash programmer) Brian Aker corrects an apparent miscommunication in a blog post: "we are just starting to roll out [Enterprise] binaries... We don't build binaries for Debian in part because the Debian community does a good job themselves... If you call MySQL and you have support we support you if you are running Debian (the same with Suse, RHEL, Fedora, Ubuntu and others)... someone in Sales was left with the wrong information"
This discussion has been archived. No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
 Full
 Abbreviated
 Hidden
More
Loading... please wait.
  • No Digg (Score:5, Informative)

    by AKAImBatman (238306) * <akaimbatman@NOsPaM.gmail.com> on Monday December 18 2006, @09:30AM (#17284936) Homepage Journal
    1. There's no such thing as unbiased. Especially on a page that gives a fairly abstract review.

    2. This article is 2 years old. Everything in its comparisons is out of date.
    • Re:No Digg (Score:5, Informative)

      by electroniceric (468976) on Monday December 18 2006, @09:59AM (#17285212)
      Just to continue on your good points, especially troubling is the fact that this article compares the then-unreleased MySQL 5 to the Postgres 7.x series. Nearly all the drawbacks to Postgres that this article highlights have been addressed in the 8.x series.

      We run Postgres for our main business application and the main limitations are of two forms:
      1) Depth of community
      The Postgres community is great - very responsive and knowledgeable, but its size is a limitation in a number of ways. The ODBC driver is a bit of stepchild to the main project, and some key functions like dblink that address missing features like cross-database selects are relegated to /contrib, and rely on their individual authors for nearly all maintenance. This means that as a user you are more likely to bump up against the bleeding edge earlier than in communities where these outside-the-core projects are more supported.

      For the same reason a key subset of its documentation is very sparse. Documentation for the core system is thorough, clear and concise, but anything in contrib or any projects like the ODBC or .NET drivers are much less like to have the same quality of documentaton. Postgres' extremely powerful GIST indexes are unparalled as a feature, but you need a background in theoretical CompSci to figure them out, thanks to limited documentation (note to aspire database index geeks - I would gladly buy a book on GIST aimed at proficient DBAs who are not giants of theoretical CS). Likewise its procedural languages: thanks to its architecture and open codebase, Postgres offers more server-side languages than any other database that I know of, but few of them have more than basic documentation, let alone the stacks of books you'd find with other procedural languages.

      2) Postgres is very close to being a true enterprise contender (unlike MySQL, which is evolving that direction but distinctly further off), but lacks some key features like XML handling, a more comprehensible approach to result sets (anyone who's dealt with rowtypes and casting resultsets can attest to the steep learning curve), and a userbase that has put the product through the wringer. Now that some corporate heads are getting interested (e.g. Sun, Red Hat, EnterpriseDB) hopefully some of these shortcomings will be addressed in short order.

      Don't let this outdated, apples to oranges comparison fool you: Postgres is a very solid and usable database.
  • Old news (Score:5, Informative)

    by daffmeister (602502) on Monday December 18 2006, @09:31AM (#17284944) Homepage
    From the site:

    "Last modified: February 15, 2005."
  • Old and wrong (Score:5, Informative)

    by ldapboy (946366) on Monday December 18 2006, @09:32AM (#17284962)
    postgresql has a native Win32 version, complete with an installer, service support and does not depend on cygwin.
  • by seebs (15766) on Monday December 18 2006, @09:36AM (#17285010) Homepage
    I have been involved with a smallish ("hundreds") installation of Movable Type using a mysql backend.

    One comment spammer can completely annihilate it.

    One developer I talked to once did some testing. On one simultaneous connection, mysql was way faster. By five or so, they were close. At ten, PostgreSQL was definitely winning. At a hundred, he was simply unable to get a single MySQL server to complete the test successfully, let alone do it quickly.

    The impression I get is that PostgreSQL uses more robust algorithms, with higher constant costs and lower quadratic costs. In any event, never had any problems.

    As noted elsewhere, these comparisons are quite old...

    But in any event, in my own experience, mysql is a lot easier to blow up by overloading than postgres is, at least if you have a lot of writes going on. For pure-lookup functions, it might do better -- but a lot of modern database apps are pretty compulsive about saving at least something every time someone touches them. (For instance, modern vBulletin saves last visits, threads seen, and so on; all of that adds up to a huge load on the database server.)
  • by kahei (466208) on Monday December 18 2006, @09:41AM (#17285058) Homepage

    1 -- This article is years old.

    2 -- This article is posted solely to stir up (repetitive) discussion.

    3 -- This article pretends that MySQL is a real database, even though in order to do so it has to make gigantic leaps like considering data integrity to be not really all that important in a database.

    4 -- This article trolled me.

  • by punker (320575) on Monday December 18 2006, @10:17AM (#17285390)
    This almost seems like the same comparisons we've been hearing for years.
    1) Postgresql is more full featured than MySQL
    2) MySQL is faster in a read-mostly environment
    That's pretty much the same as the anecdotal arguments have been for years.

              In my job, we moved from mysql to postgres several years ago (around PG 7.0). At the time, we needed to make the move for performance reasons. We are in a read-write system, and MySQL's locking was killing us (this was before InnoDB was well established). The features are better too, as our developers were used to having data integrity features, server side programming, and all of the SQL92 constructs available. We also learned a bit about PG performance, which I'll share.

    1) Run EXPLAIN ANALYZE on everything. Postgresql is touchier about query performance than MySQL was. This just needs to be a habit if you're using PG. (You really should do performance analysis no matter your DB. It's just a good practice). The biggest gain will be making sure you're using index scans rather than sequential scans.

    2) Use persistent connections. Everyone likes to point out the forking issue with PG vs. MySQL's threaded. PG's connection handling is slow, there's no doubt about it. But there's an easy answer. Just limit how often you connect. If you can keep a connection pool, and just reuse those connections, you'll save this big hit.

    3) Full vacuum and reindex regularly. We've found the docs to be a bit off on this. It indicates that you should run these occasionally. If you're in a read-write system, a full vacuum on a regular basis is very important. It really doesn't take that long if you do it regularly. Also, we've had trouble with indexes getting unbalanced (we see 50->90% tuple turnover daily). This has gotten better, but it doesn't hurt to let your maintenance scripts make things ideal for you. So, we run a full vacuum and reindex of our tables nightly through cron.

    4) Get your shared memory right. PG's shared buffers is probably the most important config attribute. It controls how much of your DB is memory resident vs disk resident. Avoiding disk hits is a big deal for any DB, so get this right. If you can fit your whole DB in memory, then do it. If not, make sure your primary tables will fit. The more you use the shared memory, and the less you have to page data in/out, the better your overall performance will be.

    Most DB systems seem to be read-mostly, so I can understand the performance comparisons focusing on that. In our read-write system though, the locking was the biggest issue and it tilted the performance comparison toward PG.
  • by darekana (205478) on Monday December 18 2006, @10:42AM (#17285728) Homepage
    http://tweakers.net/reviews/657 [tweakers.net]

    They compare PostgreSQL 8.2 vs MySQL 4.1.20 and MySQL 5.1.20a.
  • by Hornsby (63501) on Monday December 18 2006, @11:25AM (#17286280) Homepage
    I had to make a decision recently between Mysql and Postgresql for a database composed of many tables with greater than 50,000,000 rows. While going through the decision making process, I loaded a sample table with 50,000,000 rows to do some benchmarks. The first thing I had to do to run my tests was index the table. I started with Mysql using a InnoDB table type. I had both database servers relatively tuned to the hardware they were running on. I ran the create index with MySQL and detached my screen session. I came back several hours later to find MySQL was doing something along the lines of INDEX via REPAIR SORT. After some reading, I learned that this takes an order of magnitude longer than building an index the "normal" way and is caused by the index becoming corrupted during the creation. Okay... so, I restarted this process several times and encountered the same problem. This is clean data mind you that has already been exported from an existing SQL server. I duplicated my install on a second server and had the same problems. Very annoyed with MySQL, I gave Postgres a try. It worked on the first time in less than 25 minutes without issue. Since then I've been using it on 250,000,000 row datasets without issue. It's always reliable, and as long as you remember to use CURSORS for huge SELECT statement, it's painless to work with.
  • by Frater 219 (1455) on Monday December 18 2006, @12:12PM (#17286996) Journal

    Does the Internet's favorite DBMS have an IP address datatype yet?

    How about MAC address? CIDR block?

    "An IP address is just a 32-bit unsigned int, duh. Any DBMS can store those."

    Wrong. A datatype isn't just about storage, but also about operations. In PostgreSQL, when you do a SELECT across a table with IP addresses in it, you get them formatted and displayed as IP addresses, not as opaque ints. Likewise with CIDR blocks, like "192.168.42.0/23". There's also a comparison operator for asking whether an IP address is within a CIDR block.

    If you're implementing a network registration system or an incident logging system, how much of your time do you want to waste staring at opaque ints like 3232246272 rather than IP addresses like 192.168.42.0 when you're trying to debug it?

    MySQL is a bimbo, a fratboy: it's easy, but so shallow! The amount of time you save in one-time setup, you will lose many times over in all the little annoyances and deficiencies of a DBMS that was originally designed by folks who didn't really believe in DBMSes. Over time they've slowly been shamed into including many of the features they used to despise: transactions, relational integrity checks, and so on. But there's still so much missing ... not just essential integrity features, but little fiddly bits like good datatype support, the kinds of things that make your life easier (as a programmer or as a DBA) in the long run.

    • Re:Foreign Keys (Score:5, Insightful)

      by mwanaheri (933794) on Monday December 18 2006, @09:34AM (#17284976)
      Foreign keys are more than nice, they are essential. Unless, maybe you don't care about the integrity of your data or want to make the necessary checks in their application. The latter should keep their eyes down and their mouth shut if the talk is about 'speed' of any rdbms, off course.
      • Re:Foreign Keys (Score:5, Insightful)

        by CaptainZapp (182233) * on Monday December 18 2006, @10:04AM (#17285256) Homepage
        Foreign keys are more than nice, they are essential.

        Bingo!

        It doesn't cease to amaze me, when the Mysql croud argues that "you don't really need those pesky integrity stuff, it just slows down the database."

        Guess what guys; You're dead wrong!

        Any DBA worth his salary will enforce data integrity on the lowest possible level, which means constraints (however implemented) on the object level.

        Sure, you can let your coders in Bengaluru ensure that the primary key is unique instead of just applying a unique index and the same goes for referential constraints between tables. You can implement them in the application just fine until somebody overlooks some minor detail in the code and you're royally fucked!

        Again! Foreign keys or triggers are not "niceties". They are essential in implementing an industry strength database; period!

        • Re:Foreign Keys (Score:5, Insightful)

          by Branko (806086) on Monday December 18 2006, @10:45AM (#17285760)
          Your app should be checking itself anyway.

          Actually it shouldn't (in this context). Typically, one database will have several client applications attached to it. If data consistency is not checked at DB level, then:

          • Bug in single application might compromise the data consistency of the whole system.
          • You must keep all of your applications precisely synchronized.
          • You are repeating the job of implementing the same consistency logic across all applications instead of implementing it only once - in database.
          • Implementing these sorts of checks can be difficult to do correctly at the application level in a concurrent environment typical for a DBMS.
          • Data consistency at DB level is directly supported by modeling tools, so you can plan for it and visualize it early enough to spot problems and communicate it to the other team members more easily.
          • Re:Foreign Keys (Score:5, Insightful)

            by tacocat (527354) <tallison1@twmi.rr . c om> on Monday December 18 2006, @01:58PM (#17288880)

            Additionally, databases generally can do this faster than the application code. I can say this because databases are written in C and optimized and debugged for years. Applications are rarely (relatively) written in C and have not been debugged for years when released.

            This is something that actually really pisses me off about Ruby, Rails, and ActiveRecord. ActiveRecord is an insane violation of everything that a database has been built to do. It breaks consistency, violates keys, ignores so many rules... And it's beats the crap out of a database to do what a database is designed to do and can handle much faster.

            This is regardless of the flame wars of Postgres vs MySQL.

        • Re:Foreign Keys (Score:5, Insightful)

          by tacocat (527354) <tallison1@twmi.rr . c om> on Monday December 18 2006, @01:54PM (#17288818)

          When are you non-database types going to stop saying "Your app should be checking itself anyway."

          This is an insanely inneficient method of execution. It's also highly presumptive.

          Inneficient: If you are going to insert a record you have to first check to make sure it's not there. Then if it is there you have to change your INSERT to an UPDATE. This is dumb. Some databases do a INSERT OR UPDATE. but if they don't, it's faster to do an INSERT, handle failure, UPDATE. Alternatively -- UPDATE and INSERT on ZERO ROWS CHANGED. This means you have to run less than 2 queries on average. Your app should check method guarantees two SQL statements are executed every single time.

          Dumb. Say you check for a record to exist. You get a "NO" answer. While you are preparing and executing your next INSERT, some other process or a thread inserts that same record into the databse. Now you have an error and you still don't know what to do. In short, you're in a pretty bad way.

          Presumptive. In all my years of living I've never seen any company happy with the only interface to the data being through the application interface. Especially with a database on the back end. The business types, Marketing in partitular, love to screw with database information to try and identify trends, patterns, and correlations between the customer behaviour, product representation, and sales metrics. It is presumptive that the application can safely contain all of the business logic and you can assume that no one will ever come in the back end and change something -- thereby breaking all your business rules.

          The other consideration is that the business logic contained in a database is going to run a heck of a lot faster on the database than anything you can dream up in your application, unless the application is written in C. Databases are generally written in C/C++. Applications are generally written in Java,Perl,Python,Ruby. None of these can compete with C. Add to that the fact that databases have been designed for years to do only one thing -- manage data. Do you seriously think you can out perform a decade of database optimization in a ruby script?

          If you are going to base an application on data it would be useful to know how to capitalize on the features of a database rather than trying to repeat it. At the very least, you are less likely to introduce bugs.

          • Re:Foreign Keys (Score:5, Informative)

            by Tony Hoyle (11698) <tmh@nodomain.org> on Monday December 18 2006, @10:24AM (#17285470) Homepage
            Untrue.

            The client library is GPL. That means you cannot create a commercial program that uses it without using the commercial licensed version. Which is $200 per client

            You can't even create a library and not ship mysql - the mysql site is very clear that they consider distributing a program that *uses* mysql as being exactly the same as distributing mysql itself:

            http://www.mysql.com/company/legal/licensing/comme rcial-license.html [mysql.com]

            Typical examples of MySQL distribution include: ...
                    * Selling software that requires customers to install MySQL themselves on their own machines.

            Specifically:

                    * If you develop and distribute a commercial application and as part of utilizing your application, the end-user must download a copy of MySQL; for each derivative work, you (or, in some cases, your end-user) need a commercial license for the MySQL server and/or MySQL client libraries.

            This makes mysql unusable for anything except large products. Our entire product only cost $70 for the single user version. No way in hell we're upping the price by $200 a copy.

                  • Re:Foreign Keys (Score:5, Informative)

                    by emurphy42 (631808) on Monday December 18 2006, @12:13PM (#17287004) Homepage
                    It's worth pointing out that the parent is not being sarcastic. You can sell it for whatever price you like - but you still have to make the source available, and you can't place any restrictions on your customers selling copies for whatever price they like. In practice, this tends to drive the cost of GPLed software down to $0.
            • Re:Foreign Keys (Score:5, Insightful)

              by vadim_t (324782) on Monday December 18 2006, @11:10AM (#17286088) Homepage
              Well, I sure hope you never work on anything serious.

              The database's function is to provide a RELIABLE storage for your data. Part of the whole reliability thing is making sure crap can't get in, because once it's there everything goes to heck.

              For instance, let's take a shopping cart. Can an order be for a negative quantity? If your app doesn't work that way (it could, using a negative amount for returns for example), and you still allow it in the DB, then all your reporting goes to heck, as SELECT SUM... now returns the wrong thing.

              A proper database is set up in such a way that every piece of data in it makese sense. This means for instance not having things like orders hanging around without in the void without being linked to some client. This is something easily ensured by foreign keys. Otherwise you have an utter mess - the total of the orders in the database doesn't match the sum of the orders of all clients!

              If you put your checks in the database, you have a guarantee that when somebody else codes another frontend to it (say, you had a website and now are making a special version for PDAs), if the application does the wrong thing, the database simply won't let it happen. This may cost a bit of speed, but I assure you that peace, your sanity and your ASS (if you have a boss and he's got any sense, he's not going to like it at ALL if it turns out that reports don't match reality, and that reality can't be even easily extracted) is far, far more valuable.
            • by alienmole (15522) on Monday December 18 2006, @02:29PM (#17289414)
              I suspect you're thinking of relatively simple cases where you have a single application working against a database. Which of course is the standard MySQL scenario.

              Where foreign keys and the other referential integrity features really shine is in true enterprise scenarios, when you may have hundreds or thousands of applications, written in multiple languages, working against the same shared database(s).

              In that scenario, the only viable way to duplicate the functionality of foreign keys at the application level is to have a middle layer which all other applications are required to go through. Realistically, that middle layer has to be implemented as a server, serving requests for object/record creation, update and delete over the network. Implementing it as a library to be linked into applications doesn't work well, because there are multiple applications accessing the database, and integrity enforcement needs to be centrally coordinated.

              Implementing a middleware data server for an application isn't all that difficult, but integrating it into applications can be. Most application development environments know how to talk to databases, but don't automatically know how to talk to your application-specific, language-independent, data server. So now you're writing a client library for each app dev platform used in the enterprise, and dealing with things like integrating your custom interface with data-bound controls in the user interface. BTW, this is where people start resorting to e.g. SOAP, and projects start going off the rails (no pun intended, Ruby fans).

              Luckily, as it turns out, there are already standardized, widely-available, well-supported systems that implement a centralized data serving service which enforces referential integrity. They're called databases. And foreign keys are an essential part of the service they provide.
    • Re:Foreign Keys (Score:5, Informative)

      by ShieldW0lf (601553) on Monday December 18 2006, @09:39AM (#17285048) Journal
      This is unbiased? Give me a break.

      WTF is with putting up an "unbiased comparison" between Postgres 7.2 and MySQL 5.0 when Postgres is now up to 8.2 and has most of their concerns addressed in that release, whereas MySQL is still at 5.0?

      MySQL is a great database, if you need clustering but not referencial integrity or ACID compliance, that is.

    • by Schraegstrichpunkt (931443) on Monday December 18 2006, @09:46AM (#17285106) Homepage
      You have to give the Notepad guys credit for the fact that it is an incredibly easy product when it comes to configuring it for your needs. For me, out of college, going to Vim was a culture shock because the process of learning Vim was so convoluted and drawn out for simple stuff. I know that Vim and Emacs can be much more powerful than Notepad, but there is something to be said for how easy it is for a developer to install Notepad and just start working with it.