3 ms·

http://memcached.org/ http://memcached.org/ used to be. I haven't done system architecture in about 2 years but when we were looking at in memory databases, it

by joeblau 12y ago

http://memcached.org/ http://memcached.org/ used to be. I haven't done system architecture in about 2 years but when we were looking at in memory databases, it came down to Redis or Memcache. Depending on what you need your database for, there are some that perform better than others. You can check this site for comparisons: http://kkovacs.eu/cassandra-vs-mongodb-vs-couchdb-vs-redis http://kkovacs.eu/cassandra-vs-mongodb-vs-couchdb-vs-redis

astrodust 12y ago
Memcached is just a stupid key-value store, and by stupid I mean it just stores and retrieves values. It's extremely primitive compared to Redis. It's not even close to the same thing as Redis except superficially. The key/value part of Redis is just the beginning. The values themselves can be of several different types that allow for a lot more flexibility in how you store and query data.
BurningFrog 12y ago
Redis is normally not in memory. Everything is written to disk and survives a power failure. Memcached is just a cache. Don't store anything there you can't lose.
- tim333 12y ago
  Not sure that's quite right. From the docs: >In order to achieve its outstanding performance, Redis works with an in-memory dataset. Depending on your use case, you can persist it either by dumping the dataset to disk every once in a while, or by appending each command to a log.
  - BurningFrog 12y ago
    Well, it's written to disk either way. You're right that if you do the "once in a while" setup, you can lose some data in a power failure. At a previous job people started using Redis thinking it was a fast in-memory data store. It turned out we had accumulated tens of thousands of records. I haven't measured, but I doubt it's much faster than Postgres. It does have other nice features. I like using the expiring records for caching.

3 ms·

http://memcached.org/ http://memcached.org/ used to be. I haven't done system architecture in about 2 years but when we were looking at in memory databases, it

by joeblau 12y ago

astrodust 12y ago
Memcached is just a stupid key-value store, and by stupid I mean it just stores and retrieves values. It's extremely primitive compared to Redis. It's not even close to the same thing as Redis except superficially. The key/value part of Redis is just the beginning. The values themselves can be of several different types that allow for a lot more flexibility in how you store and query data.
BurningFrog 12y ago
Redis is normally not in memory. Everything is written to disk and survives a power failure. Memcached is just a cache. Don't store anything there you can't lose.
- tim333 12y ago
  Not sure that's quite right. From the docs: >In order to achieve its outstanding performance, Redis works with an in-memory dataset. Depending on your use case, you can persist it either by dumping the dataset to disk every once in a while, or by appending each command to a log.
  - BurningFrog 12y ago
    Well, it's written to disk either way. You're right that if you do the "once in a while" setup, you can lose some data in a power failure. At a previous job people started using Redis thinking it was a fast in-memory data store. It turned out we had accumulated tens of thousands of records. I haven't measured, but I doubt it's much faster than Postgres. It does have other nice features. I like using the expiring records for caching.