Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

MySQL is bazillion times faster than MemSQL

dom.as

Post reply on HN
Print view View original

11–20 of 148 posts

Re: MySQL is bazillion times faster than MemSQL

#11

Post by spudlyo »

endersshadow wrote: post #7
fusiongyro wrote: post #2

Whenever one sees a claim about new database technology outperforming standbys like MySQL and Postgres by factors of 10x or more, it's a good idea to suspect the out-of-the-box configuration isn't really durable. What kills write performance in databases is the time it takes to write to disk, not the software overhead.

For what it's worth SQL Server doesn't meet his definition of "durable." It writes a transaction log and then writes those transactions to disk on a checkpoint [1]. Typically, that checkpoint automagically happens, but you can also force it to clear the buffer with a "checkpoint" command. InnoDB also does this, too [2]. I don't know if MemSQL actually has checkpointing or what, but it's just worth noting. [1]: http:/…

I think you may be missing the point. Most databases use transaction/redo logs, it has to do with how often the writes to the transaction log are flushed. With proper durability, the transaction log is flushed with every commit, not when buffers become full or a background thread gets around to it.

Re: MySQL is bazillion times faster than MemSQL

#12

Post by __dumbideas »

endersshadow wrote: post #7
fusiongyro wrote: post #2

Whenever one sees a claim about new database technology outperforming standbys like MySQL and Postgres by factors of 10x or more, it's a good idea to suspect the out-of-the-box configuration isn't really durable. What kills write performance in databases is the time it takes to write to disk, not the software overhead.

For what it's worth SQL Server doesn't meet his definition of "durable." It writes a transaction log and then writes those transactions to disk on a checkpoint [1]. Typically, that checkpoint automagically happens, but you can also force it to clear the buffer with a "checkpoint" command. InnoDB also does this, too [2]. I don't know if MemSQL actually has checkpointing or what, but it's just worth noting. [1]: http:/…

MySQL's InnoDB has configurable durability: http://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.htm...

Re: MySQL is bazillion times faster than MemSQL

#13

Post by ericfrenkiel »

mikeash wrote: post #10
ericfrenkiel wrote: post #5

When someone writes on their intro "... and now in return I want to waste your time a bit." it's a sign that someone isn't being serious. Domas' main criticism is that our video, http://vimeo.com/44087431 , uses a MySQL with standard defaults. Since tuning a database is by definition a custom process, we wanted to demonstrate what performance you'd get "out of the box." The video speaks for itself. MemSQL can push 80…

I thought his main criticism was that MemSQL isn't durable by default, and that when you enable that it becomes incredibly slow. That's a pretty big deal, and IMO running database benchmarks on an unsafe configuration like this is extremely dishonest.

That's a bit heavy-handed; additional benchmarks will be published against a variety of configurations and other databases.

Companies use MemSQL because it uses memory as the primary locus of data. If you have a fast data problem, you couldn't use a disk-based system. At high speeds, you'd want to deploy any database in an active-active mode.

Re: MySQL is bazillion times faster than MemSQL

#14

Post by mikeash »

ericfrenkiel wrote: post #13
mikeash wrote: post #10

Earlier quoted context omitted.

I thought his main criticism was that MemSQL isn't durable by default, and that when you enable that it becomes incredibly slow. That's a pretty big deal, and IMO running database benchmarks on an unsafe configuration like this is extremely dishonest.

That's a bit heavy-handed; additional benchmarks will be published against a variety of configurations and other databases. Companies use MemSQL because it uses memory as the primary locus of data. If you have a fast data problem, you couldn't use a disk-based system. At high speeds, you'd want to deploy any database in an active-active mode.

How is it heavy handed? As I understand the article, MemSQL by default will often say that a transaction has been committed even though it only exists in memory, not on disk. Comparing that scenario with a MySQL setup which only says a transaction has been committed once it's on non-volatile storage is just wrong.

Re: MySQL is bazillion times faster than MemSQL

#16

Post by [deleted] »

ericfrenkiel wrote: post #13
mikeash wrote: post #10

Earlier quoted context omitted.

I thought his main criticism was that MemSQL isn't durable by default, and that when you enable that it becomes incredibly slow. That's a pretty big deal, and IMO running database benchmarks on an unsafe configuration like this is extremely dishonest.

That's a bit heavy-handed; additional benchmarks will be published against a variety of configurations and other databases. Companies use MemSQL because it uses memory as the primary locus of data. If you have a fast data problem, you couldn't use a disk-based system. At high speeds, you'd want to deploy any database in an active-active mode.

[deleted]

Re: MySQL is bazillion times faster than MemSQL

#17

Post by jstclair »

endersshadow wrote: post #7
fusiongyro wrote: post #2

Whenever one sees a claim about new database technology outperforming standbys like MySQL and Postgres by factors of 10x or more, it's a good idea to suspect the out-of-the-box configuration isn't really durable. What kills write performance in databases is the time it takes to write to disk, not the software overhead.

For what it's worth SQL Server doesn't meet his definition of "durable." It writes a transaction log and then writes those transactions to disk on a checkpoint [1]. Typically, that checkpoint automagically happens, but you can also force it to clear the buffer with a "checkpoint" command. InnoDB also does this, too [2]. I don't know if MemSQL actually has checkpointing or what, but it's just worth noting. [1]: http:/…

This is a little misleading; an internal checkpoint happens upon transaction commit[1]. The comment makes it sound as if one or more transactions can commit before a checkpoint writes them to disk.

[1]: http://msdn.microsoft.com/en-us/library/ms186259(v=sql.105)....

Re: MySQL is bazillion times faster than MemSQL

#18

Post by caladri »

ericfrenkiel wrote: post #5

When someone writes on their intro "... and now in return I want to waste your time a bit." it's a sign that someone isn't being serious. Domas' main criticism is that our video, http://vimeo.com/44087431 , uses a MySQL with standard defaults. Since tuning a database is by definition a custom process, we wanted to demonstrate what performance you'd get "out of the box." The video speaks for itself. MemSQL can push 80…

How do you feel about the reported performance of "SELECT * FROM table ORDER BY id DESC LIMIT 5;"? Is this something that needs to be improved there, or are you happy with that being one of the built-in anchors?

Additionally, I'm not sure that the implementation of the hard reliable case sounds very mature or even well thought-out. Having a syncer running at 20hz and waiting for it even in the synchronous path seems a bad idea. That's kind of like adding an anchor to your anchor so your speedboat can crawl while it crawls. Or was that a misrepresentation?

And who cares if the tone is serious? The criticisms seem to be valid, and ones that anyone releasing software making bold claims should expect. Statements about performance need to be qualified. Out-of-the-box behavior is not a reasonable point of comparison if (1) that's not what people do in the real world (2) the tests you use are ones that one piece of software is tuned for and the other is tuned against. Some kind of sorted index by field is necessary for some very common and desirable queries. Some of the performance gains come at an unacknowledged cost. The durability just isn't there (and for trivial reasons that could be fixed by making a few more parameters tunable, it sounds like), but is implicitly lauded by claiming to be ACID.

I don't know if you need to go looking for praise in that article. It really seems like there are some criticisms it would be beneficial to take seriously, even if you object to the author's tone or lack of praise. Even-handedness is not a marker of honesty, and honest criticism is worth the headaches it causes and the growth it spurs if you're willing to take it seriously.

Re: MySQL is bazillion times faster than MemSQL

#19

Post by cbsmith »

ericfrenkiel wrote: post #5

When someone writes on their intro "... and now in return I want to waste your time a bit." it's a sign that someone isn't being serious. Domas' main criticism is that our video, http://vimeo.com/44087431 , uses a MySQL with standard defaults. Since tuning a database is by definition a custom process, we wanted to demonstrate what performance you'd get "out of the box." The video speaks for itself. MemSQL can push 80…

On this basis though, why develop a new database system when instead you could just develop a new default configuration for MySQL?

Re: MySQL is bazillion times faster than MemSQL

#20

Post by [deleted] »

ericfrenkiel wrote: post #5

When someone writes on their intro "... and now in return I want to waste your time a bit." it's a sign that someone isn't being serious. Domas' main criticism is that our video, http://vimeo.com/44087431 , uses a MySQL with standard defaults. Since tuning a database is by definition a custom process, we wanted to demonstrate what performance you'd get "out of the box." The video speaks for itself. MemSQL can push 80…

[deleted]
Post reply on HN