Data and slices

A Studio run needs a slice: one venue, one or more symbols, a kind, a range. Two surfaces produce one. The picker in the toolbar (crates/vike-studio/src/picker.rs's SlicePicker) is the authority on what is runnable; the Data tool (crates/vike-studio/src/data_browser.rs's DataBrowserPane) browses everything the store holds, and a click there feeds the picker.

What the picker lists

SlicePicker::refresh enumerates the store through HistStore::list_series — the trait, so a remote RPC store lists exactly like the local one — and the three filters it applies live once in crates/vike-studio-core/src/run.rs. Two families are pickable, in this order:

• Bars — every kind=bar (venue, symbol, interval) (bar_series), picked as a SliceKind::Bars slice and replayed through the strategy engine; shown as binance · BTCUSDT · 1m.
• Ticks — every (venue, symbol) with a recorded series in REPLAYABLE_TICK_KINDS, which is quote, trade and book (tick_series), picked as a SliceKind::Ticks slice and replayed through tick replay. One row per pair: the replay scans all three lanes for a symbol and merges them, so a symbol recorded as quotes and trades must not appear twice. Shown as polymarket · TKN · ticks.

The picker's header records that before the tick family existed, tick series were listed nowhere and the Studio had no tick path at all.

A third family is disclosed without being pickable: instruments the store holds only as kind=depth (depth_only_series). They render greyed under the pickable rows and as a ⚠ depth-only chip in the toolbar, with DEPTH_NOT_REPLAYABLE on hover — placed on the surface because the person who needs it is staring at a picker that does not list an instrument they know they recorded:

Recorded, but not replayable. kind=depth is the CONFLATING L2 lane — periodic full snapshots with every intermediate book state discarded — and a backtest over teleporting depth reports fills it could never have got, so the tick replay reads the lossless quote/trade/book lanes only. Record one of those for this instrument to make it runnable.

tick_series's doc gives the two independent reasons the arm is refused even though it would compile: the replay has no depth lane to read, and folding depth into the book lane would hand a strategy conflated snapshots under the name of a lossless book. The depth and book layouts in the store kinds are the store's own statement of that difference.

Range and extra symbols

The picker loads the whole series range — TsRange::all(); the header names a date-range sub-picker as a follow-up. A tick pick can carry extra symbols: the + symbols (a, b) box beside the combo folds a comma-separated list into one tick slice, deduplicated, so a cross-instrument tick strategy gets all its series in a single run. The box is inert for a bar row, deliberately: multi-symbol bar runs need aligned bar counts, which a free-text box cannot promise, and load_slice_bars rejects a misaligned set with a readable error rather than letting the engine's own assert panic a worker thread.

A failed scan is not an empty store

The picker's header carries the hazard in its own words: an enumeration that failed and a store that is genuinely empty are different facts, and this picker renders them differently. It used to unwrap_or_default() both lists, so a store that could not be read drew the same empty combo — and the same "no data in store" text — as one holding nothing, and the operator read "backfill some history" off a surface whose real problem was that the datahub had gone away.

So the combo has four states, not two: series scan failed (plus a ⚠ scan failed chip whose hover carries SERIES_SCAN_ADVICE — fix the store, and for a remote datahub, is the server up? — then ⟳ Refresh), no data in store when nothing at all is recorded, nothing replayable when the store holds only depth, and select data…. The empty results panel asks the same question in the same order.

Refresh is a one-shot walk, on open and on ⟳ Refresh, never per frame. One thing it cannot do: the store root is resolved once at startup, so changing the environment variable and clicking Refresh does nothing — the Data pane's comment says so where the old hint used to suggest it.

The Data tool

The Data tab renders the same venue → symbol → series catalog the Data Manager's Stored tab renders — vike_data_manager::stored_catalog_ui, the de-duplicated extraction — so what you see here is the catalog: Symbol | Kind | Coverage | Rows | Size | Updated, one rollup header per venue, sortable columns. DataBrowserPane::refresh walks the full inventory, every kind and not just bars, through HistStore::inventory, a manifest-only read with no data scan that the remote store serves over RPC. The grid's natural width is about 690 px against a 340 px panel, so it scrolls horizontally rather than squeezing its fixed cells into a broken clip.

Click a bar-series row and the shell selects it as the run slice through SlicePicker::select_by_key. A tick-series row, which carries no interval, yields nothing here — there is no DataSlice for it through this route yet; pick ticks from the combo. An inventory scan that fails renders "Inventory scan failed" with the reason, never the "no data yet" hint; an empty store says to backfill history — the Data Manager's Backfill, or vike-backfill — then Refresh.