Vane Data / Reference

File inspection

Inspection functions read resolved FILE metadata without decoding content.

Signature

example.py

vane.file_path(value) -> Expression
vane.file_size(value) -> Expression
vane.file_exists(value) -> Expression
vane.file_stat(value) -> Expression
vane.file_mime_type(value, detect="metadata") -> Expression
vane.guess_mime_type(value) -> Expression

SQL: file_path(file), file_size(file), file_exists(file), file_stat(file), file_mime_type(file [, detect]), and guess_mime_type(bytes). Expression methods: expr.file_path(), expr.file_size(), expr.file_exists(), expr.file_stat(), expr.file_mime_type(...).

Parameters

Name	Type	Description	Default
value	FILE-family value or Expression	Object to inspect	Required
detect	"metadata", "content", or "auto"	MIME detection source	"metadata"
value (guess_mime_type)	BLOB value or Expression	Raw bytes to sniff	Required

file_mime_type with metadata (the default) uses the declared content_type and falls back to the URL suffix without opening the object. auto prefers declared and resolved metadata before sniffing content, while content sniffs content directly. guess_mime_type sniffs bytes directly.

Returns and errors

file_path returns VARCHAR, or NULL for a NULL input. file_size returns UBIGINT, or NULL for a NULL input. file_exists returns true when the object is present, false when it is missing, and NULL for a recoverable access error. file_mime_type and guess_mime_type return a MIME type string (VARCHAR), or NULL when the type cannot be identified. file_stat returns STRUCT(url VARCHAR, object_size UBIGINT, last_modified TIMESTAMP, version VARCHAR, etag VARCHAR, content_type VARCHAR) (vane.FileStat in Python) with NULL for unknown fields. Other access failures raise.

Example