![]() The "JSONB" name is inspired by PostgreSQL, but the on-disk format for SQLite's JSONB is not the same as PostgreSQL's. JSON has been optimized to death it seems like you could get the 2x gain and avoid a new format with normal optimization, or perhaps compile-time options for SIMD JSON techniques The advantage of JSONB over ordinary text RFC 8259 JSON is that JSONB is both slightly smaller (by between 5% and 10% in most cases) and can be processed in less than half the number of CPU cycles. ![]() ![]() To be honest the wins (in this draft) don't seem that compelling I thought the MessagePack data model corresponded pretty much exactly to JSON ? It feels like it would be better to use a known binary encoding. Hm I googled and found this draft of the encoding. I think the only difference at this point is that Python doesn't move integer-like keys to the front, because unlike JavaScript, Python properly distinguishes between different key types. Python made a similar change in version 3.6 (officially since 3.7), both with regards to insertion order and later values overwriting earlier ones while preserving order. (Note that '1' was moved to front, and 'a' comes before 'b' even though the associated value comes from the final entry in the JSON code.) (Of course, symbols cannot be represented in JSON.)Īnd duplicate properties in JSON are guaranteed to be treated the same way they are in object literals: a duplicate overwrites the previous value but doesn't change the order of the key. > It's the JS part of JSON that imposes non-duplicate keys with undefined order constraint.Īctually since ES2015 the iteration order of object properties is fully defined: first integer keys, then string keys in insertion order, finally symbols in insertion order. Yes, JS and Python behaviour are not the same for all cases, however, non-integer keys do maintain order across Python and JavaScript. Order is only lost if the underlying containers are unordered." Since 3.7 dict maintains insertion order. Similarly, Python json module guarantees that "encoders and decoders preserve input and output order by default. Within each component of the prototype chain, all non-negative integer keys (those that can be array indices) will be traversed first in ascending order by value, then other string keys in ascending chronological order of property creation. > The traversal order, as of modern ECMAScript specification, is well-defined and consistent across implementations. > Properties are visited using the same algorithm as Object.keys(), which has a well-defined order and is stable across implementations In addition, some internally used or deprecated types are available, but are not listed here.Yes, but it's not impossible to achieve it in practice.įor example, JavaScript JSON.stringify and JSON.parse have well-defined behaviour: Most of the alternative names listed in the “ Aliases” column are the names used internally by PostgreSQL for historical reasons. Table 8.1 shows all the built-in general-purpose data types. Users can add new types to PostgreSQL using the CREATE TYPE command. PostgreSQL has a rich set of native data types available to users. Constructing Ranges and Multiranges 8.17.7. Built-in Range and Multirange Types 8.17.2. Composite Type Input and Output Syntax 8.17.
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