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Diffstat (limited to 'wiki/mysql/choose-something-else.md')
| -rw-r--r-- | wiki/mysql/choose-something-else.md | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/wiki/mysql/choose-something-else.md b/wiki/mysql/choose-something-else.md index a951e57..3d043e3 100644 --- a/wiki/mysql/choose-something-else.md +++ b/wiki/mysql/choose-something-else.md @@ -62,16 +62,26 @@ familiar with other SQL implementations). ### Preserving Data ... against unexpected changes: like most disk-backed storage systems, MySQL -is as reliable as the disks and filesystems its data lives on. - -... against loss: hoo boy. MySQL's default approach to -[backups](http://dev.mysql.com/doc/refman/5.5/en/backup-methods.html) is to -either dump data to SQL periodically (slow and an inefficient use of space, -with little support for incremental backups) or to use binary logs (plus a -base filesystem backup) for ongoing backups. (Binary logs are also the basis -of MySQL's first-party replication system.) If neither of these are -sufficient, you're left with purchasing [a backup tool from -Oracle](http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_mysql_enterprise_backup). +is as reliable as the disks and filesystems its data lives on. However, the +implicit conversion rules that bite when storing data also bite when asking +MySQL to modify data - my favourite example being a fat-fingered `UPDATE` +query where a mistyped `=` (as `-`, off by a single key) caused 90% of the +rows in the table to be affected, instead of one row, because of implicit +string-to-integer conversions. + +... against loss: hoo boy. MySQL, out of the box, gives you two approachesœ to +[backups](http://dev.mysql.com/doc/refman/5.5/en/backup-methods.html): + +* Dump to SQL with `mysqldump`: slow, relatively large backups, and + non-incremental, or +* Archive binary logs: fragile, complex, over-configurable, and configured + badly by default. (Binary logging is also the basis of MySQL's replication + system.) + +If neither of these are sufficient, you're left with purchasing [a backup tool +from +Oracle](http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_mysql_enterprise_backup) +or from one of the third-party MySQL vendors. Like many of MySQL's features, the binary logging feature is [too](http://dev.mysql.com/doc/refman/5.5/en/binary-log.html) |