Logging & Verbosity¶

FastFlowTransform exposes uniform logging controls across all CLI commands plus a dedicated SQL debug channel for tracing rendered SQL, dependency loading, and auxiliary queries.

CLI Flags¶

-q / --quiet → only errors (ERROR)
(default) → concise warnings (WARNING)
-v / --verbose → progress/info (INFO)
-vv → full debug (DEBUG) including SQL debug output

-vv automatically flips on the SQL debug channel (same effect as FFT_SQL_DEBUG=1).

SQL Debug Channel¶

Enable it to inspect Python-model inputs, dependency columns, and helper SQL emitted by data-quality checks:

# full debug (recommended)
fft run . -vv

# equivalent using the env var (legacy behaviour retained)
FFT_SQL_DEBUG=1 fft run .

Usage Patterns¶

fft run . -q     # quiet (errors only)
fft run .        # default (concise)
fft run . -v     # verbose progress (model names, executor info)
fft run . -vv    # full debug + SQL channel

Parallel Logging UX¶

Each node emits start/end lines with duration, truncated name, and engine abbreviation (DUCK/PG/BQ/…).
Output remains line-stable via a thread-safe log queue; per-level summaries trail each run.
Failures still surface the familiar “error block” per node for quick diagnosis.

Notes

SQL debug output routes through the fastflowtransform.sql logger; use -vv or FFT_SQL_DEBUG=1 to reveal it.
Existing projects do not need changes: the environment variable keeps working even without -vv.