What's the fastest way to export/import a mysql database using innodb tables?
I have a production database which I periodically need to download to my development machine to debug customer issues. The way we currently do this is to download our regular database backups, which are generated using "mysql -B dbname" and then gzipped. We then import them using "gunzip -c backup.gz | mysql -u root".
From what I can tell from reading "mysqldump --help", mysqldump runs wtih --opt by default, which looks like it turns on a bunch of the things that I can think of that would make imports faster, such as turning off indexes and importing tables as one massive import statement.
Are there better ways to do this, or further optimizations we should be doing?
Note: I mostly want to optimize the time it takes to load the database onto my development machine (a relatively recent macbook pro, with lots of ram). Backup time and network transfer time currently aren't big issues.
Update:
To answer some questions posed in the answers:
The production database schema changes up to a couple times a week. We're running rails, so it's relatively easy to run the migrate scripts on stale production data.
We need to put production data into a development environment potentially on a daily or hourly basis. This entirely depends on what a developer is working on. We often have specific customer issues that are the result of some data spread across a number of tables in the db, which needs to be debugged in a development environment.
I honestly don't know how long mysqldump takes. Less than 2 hours, since we currently run it every 2 hours. However, that's not what we're trying to optimize, we want to optimize the import onto the developer workstation.
We don't need the full production database, but it's not totally trivial to separate what we do and don't need (there are a lot of tables with foreign key relationships). This is probably where we'll have to go eventually, but we'd like to avoid it for a bit longer if we can.
It depends on how you define "fastest".
As Joel says, developer time is expensive. Mysqldump works and handles a lot of cases you'd otherwise have to handle yourself or spend time evaluating other products to see if they handle them.
The pertinent questions are:
How often does your production database schema change?
Note: I'm referring to adding, removing or renaming tables, columns, views and the like ie things that will break actual code.
How often do you need to put production data into a development environment?
In my experience, not very often at all. I've generally found that once a month is more than sufficient.
How long does mysqldump take?
If it's less than 8 hours it can be done overnight as a cron job. Problem solved.
Do you need all the data?
Another way to optimize this is to simply get a relevant subset of data. Of course this requires a custom script to be written to get a subset of entities and all relevant related entities but will yield the quickest end result. The script will also need to be maintained through schema changes so this is a time-consuming approach that should be used as an absolute last resort. Production samples should be large enough to include a sufficiently broad sample of data and identify any potential performance problems.
Conclusion
Basically, just use mysqldump until you absolutely can't. Spending time on another solution is time not spent developing.
Consider using replication. That would allow you to update your copy in real time, and MySQL replication allows for catching up even if you have to shut down the slave. You could also use a parallell MySQL instance on your normal server that replicates the data to a MyISAM table, which supports online backup. MySQL allows for this as long as the tables have the same definition.
Another option that might be worth looking into is XtraBackup from renowned MySQL performance specialists Percona. It's an online backup solution for InnoDB. Haven't looked at it myself, though, so I won't vouch for it's stability or that it's even a workable solution for your problem.
来源：https://stackoverflow.com/questions/790055/whats-the-fastest-way-to-import-a-large-mysql-database-backup