I'm not an applications programmer (and don't want to be one), so take what I say with a grain of salt, but I was first introduced to Redis several years ago during an analytical project working with a consultancy, and I asked what it was and why they wanted to bring it in.
"Its a memory-resident key-value store!"...
"So its...a hash table?"
"Its a memory resident key-value store!"...
"And don't modern languages already come with those and why aren't we just using those internal and mature solutions rather than bringing in an arbitrary new external dependency?"
The answer is, yes, exactly!. Only, it's a hash table that can be shared across all of the different processes on the server. So if you have e.g. two different web requests that want to update some value, then that's how you do that. The other main alternative is a regular database, but that's much heavier and isn't really built in terms of "data structures".
(Redis isn't just a hash table - it's a list, a set, a queue, etc, in other words, all the standard library of a programming language, only in a way that can be shared across all the processes.)
Its a well optimized mature memory resident key-value store that can be used by arbitrary processes and threads which has an api accessible to arbitrary programming languages.
I'm not an applications programmer (and don't want to be one), so take what I say with a grain of salt, but I was first introduced to Redis several years ago during an analytical project working with a consultancy, and I asked what it was and why they wanted to bring it in.
"Its a memory-resident key-value store!"...
"So its...a hash table?"
"Its a memory resident key-value store!"...
"And don't modern languages already come with those and why aren't we just using those internal and mature solutions rather than bringing in an arbitrary new external dependency?"
blank look
"Its a memory-resident key-value store!"