A proto3 message definition with numbered fields.
Who uses it
gRPC services and anything using Protocol Buffers.
Writing Protobuf Schema
Field numbers are assigned in column order starting at one. Types are inferred from the values.
What is Protobuf Schema?
What it can hold
Protocol Buffers is a data interchange format. Protocol Buffers cannot be read without its .proto definition, because the wire format alone does not name the fields. A machine can read the table back out of it without guessing, which is what makes it safe to convert into and out of.
It keeps
- Types. A number stays a number and a boolean stays a boolean, so whatever reads the file next does not have to guess from how a value looks.
- Nested values. A cell can hold a list or an object rather than only a single value.
- A line break inside a cell, which survives rather than ending the row.
- Its own record boundaries. A reader can take one row at a time without loading the file, and a copy that was cut off part way through still yields everything before the cut.
It cannot express
- Any formatting. Bold, colour, column widths and merged cells have nowhere to go.
- A header row. Column names are repeated on every record instead, which is why a file in this format is larger than the table it holds.
What it looks like
syntax = "proto3";
message staff {
int64 id = 1;
string name = 2;
string role = 3;
string started = 4;
double hours = 5;
}Questions
How do I open Protobuf Schema files?
Protobuf Schema is written by Tablizer rather than read by it. Open the file in whichever tool the format belongs to.
Is Protobuf Schema a good format for sharing data?
It depends who is receiving it. gRPC services and anything using Protocol Buffers. If the recipient is outside that group, a plain CSV travels further than anything else.