`tables/<name>.yaml`

One file for each table. The name of the file is the name of the table. See tables for the modes, the types and the encodings.

A table file.

key	type	default	description
`columns`	map of `ColumnSpec`	required	The columns, in order.
`event_time`	string		A temporal column that orders rows in time; drives retention and time pruning.
`mode`	`TableMode`	`append`
`name`	string	required	The table's name. Must match the file name (`tables/<name>.yaml`).
`primary_key`	list of string		The key of an `upsert` table.
`renamed_from`	string		The table's previous name, to make a rename keep its data.
`retention`	`Duration`		How long rows are kept, measured on `event_time`.

`ColumnSpec`

One column.

key	type	default	description
`encoding`	`Encoding`		Overrides the default encoding for the column's type.
`filled`	`Filled`		Filled in by the server on every write, never sent: `credential` (a string column: the name of the credential that wrote the row) or `received` (a timestamp column: when the server received it).
`nullable`	boolean		Whether the column may hold NULL. Columns are required by default.
`renamed_from`	string		The column's previous name, to make a rename keep its data. Removed again once the rename is applied.
`type`	`ColumnType`	required

How rows arrive in a table (plan D6).

value	description
`append`	Rows are only ever added. The cheapest mode, and the default: facts.
`upsert`	Rows are keyed by `primary_key`; a row with an existing key replaces the old one. Dimensions.

A duration with a unit: ms, s, m, h or d (e.g. 200ms, 730d).

Type: string.

How a column is stored.

value	description
`dict`	Dictionary-encoded: every distinct value gets a small integer code. Cheap to filter and group by. The default for string, bool and date.
`plain`	Stored as values. The default for numbers and timestamps, and the right choice for high-cardinality ids nobody filters by.

What the server fills a column with (plan §9.2).

value	description
`credential`	The name of the ingest credential the row was written with.
`received`	When the server received the row.

A column type: bool, int32, int64, float64, decimal(p,s), string, date, timestamp or timestamptz.

Type: string.