database

func Open ¶

func Open(dbPath string, traceSQL bool) (*ent.Client, *sql.DB, error)

Open creates an ent client connected to the SQLite database at dbPath. The database is configured with WAL journal mode, foreign key enforcement, a 5-second busy timeout, and bulk-write-tuned pragmas. It returns both the ent client and the underlying *sql.DB for raw SQL operations (e.g., sync_status table).

DSN pragma rationale:

• synchronous(NORMAL): safe under LiteFS-replicated WAL — LiteFS provides durability via streaming replication so per-commit local fsync is redundant overhead. Halves the per-commit syscall cost on the bulk- upsert tx; the Fly primary's local WAL is replayed on replicas regardless of the local fsync mode.
• cache_size(-8000): 8 MB page cache PER CONNECTION (negative value = KiB; SQLite's default is ~2 MB). The page cache multiplies by the pool: with MaxOpenConns=10 the worst case is 10 x cache_size, and MaxIdleConns=5 retains up to 5 x cache_size for ConnMaxLifetime after a read burst. The earlier -32000 (32 MB) was sized for the primary's single-connection bulk-upsert burst but capped at 320 MB pooled — more than an entire 256 MB replica VM serving the read-heavy full-dump traffic that actually fills caches. 8 MB bounds the pool at 80 MB worst-case while still quadrupling the default for the upsert tx's page reuse.
• temp_store(MEMORY): keeps sorter and temp tables in RAM. modernc.org/ sqlite's default is FILE which on Fly hits the rootfs overlay (NOT tmpfs — verified via /proc/mounts).

When traceSQL is true the underlying *sql.DB is opened through XSAM/otelsql, so every query — ent's and the raw sync_status statements that share this handle — emits an OpenTelemetry span beneath the active request/sync span. Controlled by PDBPLUS_OTEL_SQL (default on; set false to disable). Span volume is bounded by the trace sampler: scheduled sync cycles are not traced, so the high-volume sync path produces no DB spans — see internal/otel sampler. The low-signal sql.rows and sql.conn.reset_session span types are suppressed (see WithSpanOptions below): they roughly halve the span count per request trace and remove the orphan single-span traces that pool-lifecycle and boot-time schema-migration DB operations otherwise emit with no request root.