5 ms·

Care to explain? I believe for Redis, "appendfsync everysec" is the default. The poster's point was that MySQL and Postgres both ship with something like "app

Care to explain? I believe for Redis, "appendfsync everysec" is the default. The poster's point was that MySQL and Postgres both ship with something like "appendfsync always", and you have to opt-in to the the less safe mode if you want to get more performance. Redis ships with the less safe mode pre-selected, and so has higher performance out-of-the-box.

corford 15y ago
You're right. The Postgres equivalent to "appendfsync always" is "synchronous_commit = on". Which AFAIK is the default. However, one of the nice things about redis is that even if you run "appendfsync everysec" you never run the risk of corruption. You're only risk is losing a maximum of 2 seconds worth of data. If you missed it, there's a wonderful blog post by antirez covering all of this (and a lot more) here: http://antirez.com/post/redis-persistence-demystified.html http://antirez.com/post/redis-persistence-demystified.html
- justinsb 15y ago
  All modern relational databases use this approach (it's called ARIES), so all offer the same guarantees as Redis.
  - moe 15y ago
    And to praise redis some more; it also comes with the sanest (async) replication support of any database. By far. It's literally a one-liner in the config file. No bootstrap needed, maintenance free, absolutely no strings attached. 10 seconds and you're done. Which means you'll actually use it from day 1 and never worry about it. Compare that to any other database.
deleted 15y ago
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antirez 15y ago
What I mean is simply that the default configuration file does not matter, but the point is, what are the guarantees and tradeoffs that a database system can provide? and Redis is no different than other non-in-memory DBs about this. To put Redis apart because in the default configuration file we just enable RDB persistence seems odd, it's like if with a one line commit tomorrow I "change Redis" because I alter the default configuration to AOF + fsync always. Obviously the system remains exactly the same, so systems should be compared by capabilities and not by default config files.

corford 15y ago

You're right. The Postgres equivalent to "appendfsync always" is "synchronous_commit = on". Which AFAIK is the default. However, one of the nice things about redis is that even if you run "appendfsync everysec" you never run the risk of corruption. You're only risk is losing a maximum of 2 seconds worth of data. If you missed it, there's a wonderful blog post by antirez covering all of this (and a lot more) here: http://antirez.com/post/redis-persistence-demystified.html http://antirez.com/post/redis-persistence-demystified.html

justinsb 15y ago
All modern relational databases use this approach (it's called ARIES), so all offer the same guarantees as Redis.
- moe 15y ago
  And to praise redis some more; it also comes with the sanest (async) replication support of any database. By far. It's literally a one-liner in the config file. No bootstrap needed, maintenance free, absolutely no strings attached. 10 seconds and you're done. Which means you'll actually use it from day 1 and never worry about it. Compare that to any other database.

deleted 15y ago

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antirez 15y ago

What I mean is simply that the default configuration file does not matter, but the point is, what are the guarantees and tradeoffs that a database system can provide? and Redis is no different than other non-in-memory DBs about this. To put Redis apart because in the default configuration file we just enable RDB persistence seems odd, it's like if with a one line commit tomorrow I "change Redis" because I alter the default configuration to AOF + fsync always. Obviously the system remains exactly the same, so systems should be compared by capabilities and not by default config files.