What is Persistence 5 for?
==========================

This page describes reasons for certain design decisions.

General structure
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* A key-value database.
* Keys and values are python objects.
* While the DB is offline (after a correct shutdown), all its KVPs are stored as lines in one editable file.
* DB should be able to survive powercut at any point (D in ACID).

AP/LP get
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The central idea for this database is the zero-latency (as far as python goes) reads. Therefore, the DB has all its data stored as a :code:`dict`.

CAP/CLP set
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The database allows both availability-(zero)latency and consistency (note: it's not ACID consistency, it's CAP consistency and ACID durability) variants for its writes.
All zero-latency writes are also consistent with respect to (zero-latency) reads.

Consistent get
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Later versions of the database will include remote connections, and thus also consistent reads.
These will probably be implemented as requests (same as writes).
Some connection variants may not even include availability reads/writes.