(1) DisposeAsync disposed _gate unconditionally. SemaphoreSlim.Dispose does not
complete pending async waiters, and the in-flight call's Release() then threw
ObjectDisposedException from inside the semaphore (swallowed by the finally), so
a caller parked in WaitAsync was never released and its call never returned. The
gate is now left alive - the pattern SqlPollReader documents - so the waiter is
admitted and meets the session's own guarded ThrowIf(_disposed, this).
(2) LastUsedUtc advanced only on completion, so a slow catalog call (the AdminUI
allows 20 s) was invisible to the TTL reaper for its whole duration and a session
at the edge of its TTL could be disposed mid-call. It is now stamped on entry
too.
PreferredTimestampColumn nominated the first column mapping to DriverDataType
.DateTime, and that set includes date-only types (SQL Server / PostgreSQL
'date'). A table whose first date/time column is a 'date' committed
rowSelector.topByTimestamp = <date>, making the wide-row read ORDER BY <date>
DESC LIMIT 1 - which ties for every row written that day, so 'the newest row'
became storage order among the ties.
Time-bearing candidates now outrank date-only ones; a date-only column is still
stated when it is all the table has, so such a table stays bindable. Oracle's
DATE carries a time of day and is exempt - pinned by a control dialect that
differs from the SQLite one only in the Provider it reports.
`RawBrowseCommitMapper.BuildSqlTagConfig` emitted a WideRow blob carrying only
table + columnName. A wide-row tag must also say WHICH row it reads, so both
`SqlEquipmentTagParser` (the runtime authority) and `SqlTagConfigModel.Validate`
(the authoring gate) refused it — a browse-committed Sql tag was never readable,
first silently as BadNodeIdUnknown and, since #551 put the gate on the import,
loudly at commit.
`SqlBrowseSession` now states a fourth address field: the table's preferred
date/time-typed column, computed from the columns its attributes call ALREADY
read (no extra catalog round-trip). Candidacy is decided by
`ISqlDialect.MapColumnType` reporting `DriverDataType.DateTime` — never by column
name, which would order a wide-row read by a string column that merely looks like
a timestamp. Multiple candidates tie-break on FIRST IN CATALOG ORDER (every
dialect's column SQL orders by ordinal position), so the pick is stable across
calls and servers; it is a visible, editable default the typed editor round-trips.
No candidate (a table with no date/time column) is an operator-actionable refusal,
not an invented selector: the only remaining selector is a whereColumn/whereValue
pair whose value is data, not schema, so `DescribeUncommittableLeaf` refuses that
leaf by name, names the table, and points at the tag editor.
The session and the mapper now agree via `SqlBrowseAddressFields` constants rather
than two independently spelled string literals — a disagreement there is silent,
and is exactly the shape this defect had.
`RawTagConfigGateTests`' Sql leg flips from "records the gap" to "browse-commit
output passes the gate", with the no-candidate case pinned as its own test.
ISqlDialect gains ParameterMarker (the token in the SQL text), ParameterBindName
(the DbParameter.ParameterName) and ConfigureCommand (per-command provider setup,
where Oracle will set BindByName). SQL Server and the test SQLite dialect answer
"@"+name for both spellings and no-op the hook, so SQL Server behaviour is
byte-identical — every existing expected-SQL assertion passes untouched.
SqlGroupPlanner drops its hardcoded @k/@w consts and mints base names (k0..kN, w)
that the dialect spells; SqlQueryPlan carries the emitted markers AND the matching
bind names, so SqlPollReader keeps copying the plan's pairing rather than
re-deriving a provider convention (the two diverge on ODP.NET: ":k0" in the text,
bare "k0" on the parameter). SqlCatalogLoader and SqlBrowseSession bind
schema/table through the dialect, so their bind names cannot drift from the
markers in the dialect-owned catalog SQL. Every parameter-carrying command site
calls ConfigureCommand before its first parameter.
Controlled by a new test-only ColonMarkerDialect (":name" markers, bare bind
names) that really executes against the SQLite fixture. Each leg was falsified
against the pre-change behaviour: the planner emitted "@k0", the reader bound
":k0", and a hardcoded "@schema" in the loader failed catalog load outright.
Walks schemas -> tables/views -> columns via ISqlDialect's catalog SQL, with
@schema/@table bound as parameters at every level. Column leaves carry the
dialect-mapped DriverDataType in the attribute side-panel (ViewOnly, read-only
v1).
The NodeId encoding deliberately departs from the design sketch's literal
`schema.table|column`: SQL Server permits `.` and `|` inside a quoted
identifier, so that form mis-parses (main.a.b|c reads equally as schema
`main`+table `a.b` and schema `main.a`+table `b`) and silently binds an
operator's tag to the wrong column. SqlBrowseNodeId encodes
`<kind>:<part>[|<part>...]` with `\`/`|` escaped and the kind prefix carrying
the arity; it is public because the picker body decodes it back.
The session owns the connection it is handed and closes it on dispose -- the
registry-held session is the only lifetime hook, so a non-owning session would
leak one pooled connection per reaped picker. Per-call work stays bounded by
the AdminUI's existing 20s linked CTS (BrowserSessionService.PerCallTimeout);
no second deadline is invented here.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty