Comments on: MySQL: the Pros and Cons of MyISAM Tables

By: Craig Buckler

Craig Buckler — Mon, 30 Mar 2009 16:43:10 +0000

@Tintin
The main disadvantage of InnoDB is full-text search (MyISAM offers some useful search-engine-like facilities). However, you can get around that by writing your own search routines.

If all else fails, create a MyISAM table that is purely used for full-text searches and update it only when necessary.

By: Tintin

Tintin — Mon, 30 Mar 2009 02:37:28 +0000

does anyone knows any table that shows the advantages and disavantage of MyISAM and InnoDB? Thanks.

By: Kailash Badu

Kailash Badu — Sat, 28 Mar 2009 06:37:15 +0000

My guess is that only the table structure was copied given that INNODB only saves table structure inside the data directory. Since one could actually see the tables in the second server, it gives the false impression that the database was copied successfully. However, not only the tables are empty (since data was not copied), the tables are broken, unusable in most cases as you cannot really query them.

By: Craig Buckler

Craig Buckler — Fri, 27 Mar 2009 19:01:43 +0000

@Kailash Badu
The whole MySQL data folder was copied and an identical version of MySQL was used. It worked, although I dumped the structure and data and reinstalled properly after that.

I wouldn’t really recommend that process, and it was only done following a PC failure.

By: Kailash Badu

Kailash Badu — Thu, 26 Mar 2009 18:35:31 +0000

@craig

InnoDB tables only create .frm files in the data directory which holds information on table structure. MyISAM, on the other hand, also saves data file (.myd) and index file(.myi) in the data directory. So I am surprised that you successfully copied InnoDB to another machine.

What files did you copy?

By: Craig Buckler

Craig Buckler — Thu, 26 Mar 2009 18:25:10 +0000

I recently copied InnoDB files from one Windows PC to another too. They were placed in a matching folder, but it did work.

I think there’s also a minor issue that MyISAM tables can only exist in a single file so there may be OS file size limits. But that’s really not a significant problem unless you’ve got a huge DB on FAT or FAT32.

By: Kailash Badu

Kailash Badu — Thu, 26 Mar 2009 18:15:58 +0000

Nice write-up Craig,

One important feature that distinguish MyISAM from InnoDB is that MyISAM tables are generally binary portable. If you need to move a table from one MySQL server to the other, just copy the files from first server to the second server and you are ready to go. In some instances it’s a lot handier than using say mysqldump.

@bob and nowhere did he say MySQL is faster than Oracle. Moreover, Comparing MySQL with Oracle is besides the point because the two things aren’t on the same wavelength.

By: Craig Buckler

Craig Buckler — Thu, 26 Mar 2009 18:00:27 +0000

If you’re building a banking transaction application, should you be using MySQL in the first place?

There is no reason why you can’t (as long as you choose InnoDB). Perhaps more will adopt open source databases given the current state of the banking sector!

By: Johan Martin

Johan Martin — Thu, 26 Mar 2009 16:03:28 +0000

If you’re building a banking transaction application, should you be using MySQL in the first place?

By: Craig Buckler

Craig Buckler — Thu, 26 Mar 2009 09:25:57 +0000

As mentioned, bulk inserts/updates is not a strong point of MyISAM tables. Selects are another matter – MySQL generally beats most DBs by a significant margin (although every manufacturer will tell you that theirs is the fastest – any DB can be tweaked to work better on one than another). Remember that selects are more frequent in the majority of applications.

In fact, some large-scale data warehouses have used Oracle or another DB in the backend, but used replicated MySQL servers on the frontend to serve data. That gives you the best of both worlds.