Where each part of TamarackDB lives in the Go code.

PackageRole
cmd/tamarackdb-serverThe server binary: configuration, startup, signals, ordered shutdown, the hourly PRAGMA optimize
cmd/tamarackdb-initCreates an empty database file
cmd/tamarackdb-backupThe backup tool (see Backup)
cmd/tamarackdb-demoFills a data directory with made-up data
internal/apiThe HTTP API: routing, decoding, validation, errors, logging, /metrics, /debug
internal/queueThe FIFO (see The write FIFO)
internal/txnThe write manager: a turn in the FIFO for each write, bulk delete, reset, and PRAGMA optimize, and the write counters
internal/storeSQLite: the transaction of a write, reads, the store ID, the Sequence Position counter, the query-to-SQL translation
internal/dcbEvents, tags, queries, Append Conditions, and their validation
internal/projectionThe projection wire shape and its validation, independent of internal/dcb
internal/configLoading and checking the configuration of the server and of the backup
internal/ndjsonWriting NDJSON lines
internal/buildinfoThe version string, set at build time

The shared matcher cases live in testdata/query-cases.json (see Query grammar).