Continues #1878 by @Joel-Claw, at their request. Both commits are
theirs, authorship unchanged; I only rebased them onto master and
resolved the conflict with #1909.
## The conflict, and how it is resolved
Exactly the two places I named in the review on #1878: `OpenDB` and
`Close()`. Both PRs rewrite them, and #1909 went first because it is the
correctness fix.
**`OpenDB`** — kept #1909's pinned-connection `detectSchema` and added
this PR's `prepareStatements()` after it:
```go
derr := d.detectSchema(ctx, sc)
_ = sc.Close()
if derr != nil { conn.Close(); return nil, fmt.Errorf("schema detection failed: %w", derr) }
// Statements are prepared after schema detection so they can never be
// compiled against a schema mode that turned out to be wrong (#1901).
if err := d.prepareStatements(); err != nil { ... }
```
The ordering matters and is not arbitrary: preparing before detection
would compile statements against a schema mode that #1909 exists to stop
trusting.
**`Close()`** — kept this PR's statement closing and **did not** restore
the WAL checkpoint. #1909 removed it deliberately: the handle is
`mode=ro`, so `PRAGMA wal_checkpoint(TRUNCATE)` can only ever fail with
"disk I/O error (778)" and was emitting a misleading storage-fault line
on every shutdown. That reasoning survives; the statement closing is
added in front of it.
## Verification
- Both commits cherry-picked onto `e5595ad9`
- `cmd/server` builds
- **Full `cmd/server` suite: ok, 0 failures** (not just the targeted DB
tests — after master briefly went red today from a two-PR interaction, a
full local run seemed worth the two minutes)
## Review points still open, none blocking
From my review on #1878, unchanged by the rebase:
1. Every SQL string now exists twice, once prepared and once as the
`stmtQueryRow` fallback literal, with nothing keeping them in sync. The
fallback is genuinely needed — twelve test helpers build `&DB{conn:
...}` directly and never call `prepareStatements` — but a constructor
for those helpers would remove the duplication.
2. `stmtCountObsLastHour` and `stmtCountObsLastDay` are byte-identical
SQL.
3. `OpenDB` now refuses to start rather than degrading when a Prepare
fails. Contained today, since none of the 13 prepared queries touch a
schema-conditional column, but the failure mode changed.
@Joel-Claw — your work, your credit. Ping me if you would rather take it
back.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
https://claude.ai/code/session_01Wzwr3eXseyNM7Xj598djjE
---------
Co-authored-by: Joel Claw <358739783+Joel-Claw@users.noreply.github.com>
