Module schema 

SessionDb schema DDL.

Every minor version can break schema. Old DBs that don’t match SCHEMA_VERSION fail to load with a clear “re-collect” message. There is no migration path — the raw native files under .dbg/sessions/<label>/raw/ are the durable artifact and dbg profile-* can always regenerate an index from them.

Constants

CORE_DDL

Shared meta tables — always created regardless of track or target class.

CPU_DDL

CPU-unified profile tables — sampling + EAV counters. Used by native-cpu, managed-dotnet, jvm, python, js/node target classes.

CROSSTRACK_DDL

Cross-track shared tables — joinable from either debug or profile tracks via symbol_id. Populated by on-demand collectors.

DEBUG_DDL

Debug track tables — created for every session regardless of kind. A profile session simply never writes to them.

GPU_DDL

GPU domain tables (CUDA launches, ncu metrics, memcpy transfers, framework ops). From gdbg’s current schema, with session_id added.

MANAGED_DDL

Managed-runtime tables (.NET, JVM).

NODE_DDL

Node/JS-specific tables (event-loop lag).

PYTHON_DDL

Python-specific tables (GIL contention).

SCHEMA_VERSION

Bump this on every schema-breaking change. No migrations.

Functions

apply

Apply the shared meta + debug + cross-track DDL plus the per-class domain tables. Safe to call on a fresh or existing DB; uses CREATE TABLE IF NOT EXISTS everywhere. Schema-version enforcement happens in SessionDb::open, not here.