Is there a faster way to load mysqldumps?

Question

mysqldump is reasonably fast, but dumps of a medium-sized database (20-30 megs) take several minutes to load using mysql my_database < my_dump_file.sql

Are there some mysql settings I can tune to speed up the load? Is there a better way to load saved data?

I've experimented using the mysqlimport utility with CSV-based dumps. These load slightly--but not appreciably--faster. I'm tempted to just copy raw database files around, but that seems like a bad idea.

Answer 1

Make sure you are using the --opt option to mysqldump when dumping. This will use bulk insert syntax, delay key updates, etc...

---

If you are ONLY using MyISAM tables, you can safely copy them by stopping the server, copying them to a stopped server, and starting that.

If you don't want to stop the origin server, you can follow this:

1. Get a read lock on all tables
2. Flush all tables
3. Copy the files
4. Unlock the tables

But I'm pretty sure your copy-to server needs to be stopped when you put them in place.

Answer 2

There is an method for using LVM snapshots for backup and restore that might be an interesting option for you.

Instead of doing a mysqldump, consider using LVM to take snapshots of your MySQL data directories. Using LVM snapshots allow you to have nearly real time backup capability, support for all storage engines, and incredibly fast recovery. To quote from the link below,

"Recovery time is as fast as putting data back and standard MySQL crash recovery, and it can be reduced even further."

http://www.mysqlperformanceblog.com/2006/08/21/using-lvm-for-mysql-backup-and-replication-setup/

Answer 3

Are you sure the data is sane, and there aren't any filesystem or system performance issues? Several minutes for a 20-30 meg database is a long time. I'm on a MacBook with 2GB of RAM, a 320GB HD and the standard 2.1GHz processor. I grabbed one of my databases for a quick benchmark:

gavinlaking$ du -sm 2009-07-12.glis
74  2009-07-12.glis
gavinlaking$ mysql -pxxx -e "drop database glis"
gavinlaking$ mysql -pxxx -e "create database glis"
gavinlaking$ time mysql -pxxx glis < 2009-07-12.glis 

real    0m17.009s
user    0m2.021s
sys 0m0.301s

17 seconds for a 74 megabyte file. That seems pretty snappy to me. Even if it was 4 times bigger (making it just shy of 300 megabytes), it finishes in just under 70 seconds.

Answer 4

maatkit - parallel dump

and

maatkit - parallel restore

Very fast.