Type
import type { Type } from "https://googleapis.deno.dev/v1/bigtableadmin:v2.ts";
Type
represents the type of data that is written to, read from, or stored
in Bigtable. It is heavily based on the GoogleSQL standard to help maintain
familiarity and consistency across products and features. For compatibility
with Bigtable's existing untyped APIs, each Type
includes an Encoding
which describes how to convert to/from the underlying data. This might
involve composing a series of steps into an "encoding chain," for example to
convert from INT64 -> STRING -> raw bytes. In most cases, a "link" in the
encoding chain will be based an on existing GoogleSQL conversion function
like CAST
. Each link in the encoding chain also defines the following
properties: * Natural sort: Does the encoded value sort consistently with the
original typed value? Note that Bigtable will always sort data based on the
raw encoded value, not the decoded type. - Example: STRING values sort in
the same order as their UTF-8 encodings. - Counterexample: Encoding INT64 to
a fixed-width STRING does not preserve sort order when dealing with
negative numbers. INT64(1) > INT64(-1), but STRING("-00001") >
STRING("00001). - The overall encoding chain sorts naturally if every link
does. * Self-delimiting: If we concatenate two encoded values, can we always
tell where the first one ends and the second one begins? - Example: If we
encode INT64s to fixed-width STRINGs, the first value will always contain
exactly N digits, possibly preceded by a sign. - Counterexample: If we
concatenate two UTF-8 encoded STRINGs, we have no way to tell where the first
one ends. - The overall encoding chain is self-delimiting if any link is. *
Compatibility: Which other systems have matching encoding schemes? For
example, does this encoding have a GoogleSQL equivalent? HBase? Java?
§Properties
Aggregate
Bytes
Int64