People used to get filthy rich (hi there Larry) building databases (which has all sorts of data access & management goodies) until 21st century came along and in the name of "progress" a hashtable with an HTTP interface was called a "database". Of course as nod to the said filthy rich guys from the 20th century we called them "noSQL" "databases" so as to let them continue to charge money from all those silly people in the 20th century that built their information systems on (the now "defunct" :) "databases".
> All the in-memory stuff is nothing but a cache, distributed or not.
That's flat out wrong.
A cache is a limited store that maintains a sub-set of the data that has been placed in it. Typically the eviction policy is temporal.
A database or datastore on the other hand requires explicit removal of data that has been placed in it.
p.s. Which is why we can meaningfully talk about "cache misses" in context of a perfectly functional cache, but "missing" data in a database is generally discussed in context of a buggy datastore or database.
p.s.s. Most certainly we can have pure in-memory datastores/databases, as semantics of a database are orthogonal to its datastore component. And you don't have to take some random hn user's word for it. Go ahead and ask Michael Stonebraker. :)
No. OPs have datastores confused with databases.
People used to get filthy rich (hi there Larry) building databases (which has all sorts of data access & management goodies) until 21st century came along and in the name of "progress" a hashtable with an HTTP interface was called a "database". Of course as nod to the said filthy rich guys from the 20th century we called them "noSQL" "databases" so as to let them continue to charge money from all those silly people in the 20th century that built their information systems on (the now "defunct" :) "databases".
> OPs have datastores confused with databases.
The other way around. All the in-memory stuff is nothing but a cache, distributed or not.
Datastore is a layer, a set of routines and interfaces, which maintains persistent storage, such as Informix C-ISAM.
I am old-school Informix DBA, so we knew that Larry has been a cheater.
> All the in-memory stuff is nothing but a cache, distributed or not.
That's flat out wrong.
A cache is a limited store that maintains a sub-set of the data that has been placed in it. Typically the eviction policy is temporal.
A database or datastore on the other hand requires explicit removal of data that has been placed in it.
p.s. Which is why we can meaningfully talk about "cache misses" in context of a perfectly functional cache, but "missing" data in a database is generally discussed in context of a buggy datastore or database.
p.s.s. Most certainly we can have pure in-memory datastores/databases, as semantics of a database are orthogonal to its datastore component. And you don't have to take some random hn user's word for it. Go ahead and ask Michael Stonebraker. :)
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