The node manager composes the start/end bounds from each backend's existing raw
reads (one authority, HistoryBounds): at-or-before = a capped reverse read
(native, or ReverseRawReader's walk-back on a forward-only backend — never
AVEVA's synthetic boundary row), at-or-after = a capped forward read. Bounds
count toward NumValuesPerNode, the start bound leads the first page, the end
bound ends the last (carried in the continuation point). Missing bound =
Bad_BoundNotFound (null, at the bound time; one-sided reads ±1 s from the
previous value, Table 1 footnotes a/b). A modified read with ReturnBounds is
Bad_InvalidArgument (Part 11 6.5.3.3).
The .NET SDK's ReadRawModifiedDetails defaults ReturnBounds to TRUE; the
existing tests built details without setting it and now set it false.
Oracle: every row of Part 11 Table 1 over three backend shapes, plus paging
concatenation, ties, Bad bounds, microsecond truncation; conformance pins the
lookup primitives on SqlServer + QuestDB.
The window-bounded pick joins (4a3b1256) let the optimizer choose, under
understated statistics, a nested-loops RANGE seek over the window with the pick
time as a residual, once per bucket (O(buckets x window rows)); the cached plan
was then reused for wide reads: gate 9 1d@1min 20 s, here 47 s / 3.6M reads.
Each pick join now carries WITH (FORCESEEK (PK_Sample (TagId, SourceTimeUtc))):
an exact-key seek on both columns per bucket under any statistics, and no
hash/merge join over the tag's history can exist (forcing one is error 8622), so
the window bound is dropped from the join. Output identical (EXCEPT both ways,
fwd/rev, incl. a mixed Double/Int64/Boolean/String/DateTime/outage tag).
Measured (6M-row tag + 86k mixed-kinds tag; ms / logical reads), understated
stats: 1d@1min 47,223/3.6M -> 253/25.6k; mixed 1d@1min 20,164/1.66M -> 137/24k;
accurate stats: 1d@1min 121 -> 160 ms, 1d@1h 79 -> 117 ms. Rejected: OUTER
APPLY TOP(1) FORCESEEK (identical), OPTION (RECOMPILE) (still 20 s under the bad
stats, and a compile per read).
StartEndJoinBackTests rewritten: understated statistics + compile-small/reuse-wide
(18,645 reads; the merged query read 1,645,845 / 23 s and failed it), accurate
statistics with 300k history rows either side (22,616), forced HASH/MERGE
refused (8622 — also failed against the merged query).
Docs: perf table + explanation; SDK-parity N2 (*ActualTime Calculated bit) and
N3 (Good String => BadAggregateInvalidInputs, SDK skips it).
- SqlServer StartEnd join-back: every pick join also carries the window predicate
(forward >= @start AND < @end, reverse > @start AND <= @end). Keyed on the pick
time alone a hash/merge/adaptive join read the tag's whole history (review:
43,657 vs 361 logical reads), and parameter sniffing reused that plan for every
tag. Forced OPTION (HASH JOIN), 1d@1h on 6M rows: 152,524 -> 6,756 reads.
- Usable picks (x/y) re-check the exact u predicate in the join, so a concurrent
HistoryUpdate Replace that turned the picked sample Bad/Empty reads as absent
(BadNoData), never a Bad row's value under Delta.
- StartEndJoinBackTests (integration): 300k history rows either side of a 1 h
window, forced HASH and MERGE joins, results identical to the unhinted plan and
Start/End correct, session logical reads < 1,000 (183 bounded; 8,055 with the
bound removed — the test fails then).
- TagIndexTests: the refused-ADD-INDEX test asserts the Warning naming the ALTER.
- Historian.md: re-measured table incl. long-history windows (output identical by
EXCEPT both ways in all 7 cases) and the forced-join read counts.
- HistoryUpdate Primary gate now reads IHistoryUpdateRoleView (PrimaryGatePolicy.ShouldServeHistoryUpdate):
the data-plane verdict but CLOSED until this node's first redundancy snapshot, so both pair nodes cannot
accept in the pre-join boot window. Single nodes open on their own singleton's first snapshot; admin-only
nodes register no view => no gate. DriverHostActor publishes it at every Primary-verdict publish point.
- SqlServer v1: the updater throws NotSupportedException on every arm; the node manager maps it to a
node-level BadHistoryOperationUnsupported (was per-item under a Good node for UpdateData/DeleteAtTime).
HistoryWrite bit still advertised on v1 (not knowable at materialise time) — documented.
- The update plan is evaluated before the Primary gate: an unservable request (Remove, IsDeleteModified,
not historized, no updater) is BadHistoryOperationUnsupported off-Primary, not BadInvalidState.
- Local-kind SourceTimestamp converted to UTC before the future-skew compare and sent as UTC.
- Hosted-service wiring extracted to BuildHistoryUpdatePosture and tested (gate source, skew, clock).
- Docs: Historian.md (boot window, ordering, node-level v1, HistoryWrite bit), CLAUDE.md.
Co-Authored-By: Claude <noreply@anthropic.com>
- BucketPlan: reverse processed reads anchored at the later time for every
aggregate: window (end, start], partial interval earliest, results stamped
with the later edge, latest first (SDK CreateSlice/GetTimestamp/backward
GetValues). SqlServer adds @bucketAdjustTicks + flips the window predicate;
QuestDB binds BucketBaseUnixTicks. IndexOf is the C# statement of the math.
- Partial bit on the interval the tag's data starts inside (SDK m_startOfData),
every aggregate but Average; per-sample reads fetch the earliest sample.
- Node manager: non-default client AggregateConfiguration =>
BadAggregateConfigurationRejected per node (ServerAggregateConfiguration,
pinned to the SDK AggregateManager defaults).
- GatewayTagProvisioner sends IntegralDivisor = 1.
- SDK parity oracle (Opc.Ua.Server calculators) in unit + both backends'
conformance suites, forward and reverse; remaining divergences documented.
- docs/Historian.md + CLAUDE.md release note (client-visible).
- IHistorianDataSource.ReadEventsAsync(..., bool reverse, ...) overload: reverse = Part 11 window (lo, hi]
newest-first by (time, id) DESC. Default forwards forward reads and throws NotSupportedException for
reverse (Null); Gateway refuses explicitly (ascending-only stream). Server answers
BadHistoryOperationUnsupported instead of silently returning the earliest N ascending.
- SqlServer / QuestDB serve reverse natively (ORDER BY time DESC, id DESC + TOP/LIMIT).
- Node manager: reverse event reads page with continuation points; direction stored in the cursor
(HistoryContinuationState.Reverse) so a resume continues in the cursor's direction; reverse tie clusters
over-fetched forward and sliced from the newest end (SliceTieCluster(reverse:)); end-only reads with a
cap page backward from EndTime (mirrors raw).
- Resumed event pages over-fetch by the boundary skip, so every non-final page is a full cap page.
- Tests: node-manager reverse paging (ties, clusters, coarse resolution, overfetch bound, resume
direction both ways, end-only, unsupported backend); shared EventReadConformance on SqlServer +
QuestDB; over-the-wire reverse paging; offline Gateway pin of the UTC DateTime.MaxValue bound through
the published client's proto conversion (in-process gRPC capture) and FILETIME.
- docs/Historian.md event paging section.
- HistoryUpdate items with SourceTimestamp > now + ServerHistorian:HistoryUpdateMaxFutureSkew
(default 1 day, <=0 disables) => BadOutOfRange in the node manager (every backend, never sent);
clock injected via OtOpcUaNodeManager.Clock (host TimeProvider).
- HistoryUpdate is Primary-only: off-Primary => BadInvalidState per node, after authorization,
same IDriverPrimaryRoleSource verdict as the native-ack gate; HistoryRead ungated.
- SqlServer: base schema requirement back to v1; SupportsModifiedTrail (v>=2). On v1 with
AutoCreateSchema=false: writes/reads/events/retention work, modified reads + HistoryUpdate =>
BadHistoryOperationUnsupported with nothing sent, retention skips SampleModified, one Warning per boot.
- QuestDB integration test pinning wall-clock TTL (far-future row evicts only partitions older
than the TTL by the wall clock), with a positive control.
- Docs: Historian.md, Configuration.md, security.md, CLAUDE.md (incl. QuestDB retry duplicates,
#674.4 anonymous-readable trail with ACL off, #674.5 not implemented).
Co-Authored-By: Claude <noreply@anthropic.com>
Every HistoryUpdate a SQL backend applies now leaves a modification trail
(prior value, principal, Part 11 update type, modification time), and
HistoryReadRaw with IsReadModified=true serves it as HistoryModifiedData.
- Core: HistoryUpdateContext threaded into all three IHistorianDataUpdater
methods; IHistorianDataSource.ReadModifiedAsync (default NotSupported =>
BadHistoryOperationUnsupported on Gateway/Null); HistoryModified* contracts.
- SqlServer: schema v2 (002_sample_modified.sql, RequiredVersion=2, docs copy);
trail written by OUTPUT ... INTO on the same MERGE/DELETE statement, so a
failed update leaves no audit row; retention purges SampleModified per tag on
the source-time cutoff; ReadModifiedAsync keyed on (SourceTimeUtc, ModifiedId).
- QuestDB: append-only {prefix}sample_modified (TTL like samples), trail row
written BEFORE the change (orphan-on-crash, never an untracked change);
existence reads now carry the prior value; ReadModifiedAsync.
- Node manager: modified reads dispatch + page via the #669 continuation store
(HistoryContinuationState gains HistoryCursorKind + LastModifiedId), gated by
the existing HistoryRead decision; session principal / key id passed to the
updater. IsDeleteModified stays unsupported.
- Client.CLI: historyread --modified.
- Tests: node-manager dispatch/paging/cursor binding/principal threading,
over-the-wire HistoryModifiedData, shared ModifiedValueConformance on both
backends, SqlServer atomicity (forced trail failure => no change) + v1->v2
upgrade + retention trail purge.
- Docs: Historian.md (Modified-value history section, schema v2 upgrade note),
security.md, Client.CLI.md, CLAUDE.md.
M1: the time-weighted family (incl. Total, formerly a pushed-down SUM) streams
raw window rows into the C# evaluator. New shared knob
ServerHistorian:MaxTimeWeightedRawRows (default 1,000,000; <=0 unbounded with a
Validate warning) flows through HistorianBackendRegistry into both providers.
The window query is capped at cap+1 (SQL Server TOP (@maxRows), QuestDB LIMIT $4);
one row past the cap throws the new Core.Abstractions
HistoryReadLimitExceededException, which the node manager maps to
BadTooManyOperations for that node. Not counted as a backend health failure;
bound rows are not counted; per-sample aggregates are not capped.
M2: reverse Interpolative is anchored at the later time (Part 13): points at
End - i*interval, emitted latest first. 10:00->09:00 @1h yields 10:00.
L1: Partial bit (0x4, = Opc.Ua.AggregateBits.Partial) on non-Bad results of a
truncated last interval (time-weighted family; per-sample family is a follow-up).
L2/L3: aligned with the SDK AggregateCalculator.GetTimeBasedStatusCode
(decompiled from Opc.Ua.Server 1.5.378.106): TreatUncertainAsBad=false counts
Uncertain time (Uncertain samples, held-into-outage, extrapolation) as Good
time; data but no non-Bad time => generic Bad (0x80000000); BadNoData only
when there is no data at all. Consequence: a live tag's latest interval reads
Good (documented).
L5: release note no longer claims Total matches the Gateway Integral exactly
(AVEVA's divisor is unverified); it notes Total is now evaluated in C# and
subject to the cap.
Tests: unit (reverse Interpolative x3, Partial, Bad vs BadNoData incl. an
open-ended outage, cap helpers, SDK bit oracles); conformance (reverse
Interpolative, raw-row cap at/over/0, bounds not counted, health unaffected);
node manager BadTooManyOperations; options default + warning. Each new
behaviour falsified by mutation (aggregator x9, data-source cap checks on
both backends against the real DBs, node-manager catch).
Moves the database-independent logic of the SQL Server historian backend into a new
shared library for the upcoming QuestDB backend (#666): status codes and bits, value/column
mapping, StoredSample + quality clamp, the AtTime and aggregate evaluators, BucketPlan,
LiveWritePreparer and HistoryUpdatePlanner (both with a resolutionTicks parameter, default 1),
tag-name rules, the bootstrap failure cache, health counters, alarm event ids, the event
continuation and severity clamp. The SQL Server backend now calls it; its T-SQL, TVP
builders, connection, bootstrapper and catalog stay.
Tests: StatusCodeOracleTests, ValueWriterPrepareTests, the column half of SampleRowMapperTests
and ProcessedReadTests.Every_enum_member_is_either_served_or_refused move to the new
Sql.Common.Tests under the same names. SqlServer integration tests get mechanical renames
only. Test-name set across the three projects is identical to the baseline (160 tests).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- Historian.md: Empty samples always Bad (writer/updater/read clamp),
long-name refusal, 5 s bootstrap failure cache, AtTime after now, info-bit
masking, HistoryUpdate does NOT type-check (M-1 decision), DeleteRaw
needs both bounds, reverse Raw paging, the historian/historization metric
prefixes, and provisioning numeric-only lines qualified as Gateway.
- CLAUDE.md numeric-only lines qualified as Gateway backend.
- Stale 'sole historian' lines in DriverLifecycle, ServiceHosting and the
retired Wonderware stub; Client.CLI exit-code contract.
- ServerHistorianOptions: Endpoint/Backend XML docs untangled, Validate()
indented; Program.cs comments are backend-neutral; T10 week-test day count.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- I-1: an Empty sample is always Bad. The writer stores a non-Bad NaN/Inf as
Empty+BadOutOfRange and any other non-Bad Empty as BadNoData; the updater
refuses a non-Bad Empty with BadInvalidArgument; reads clamp a legacy
non-Bad Empty row to BadNoData (Raw and AtTime).
- Tag/source names over 400 chars are refused, never truncated: writer
per-tag failure, updater BadInvalidArgument, reads not-found, events none.
- HistorianInfoBits masks the historian bits before setting one.
- AtTime past now, stepped from the last sample => UncertainDataSubNormal.
- Bootstrapper: logger, 5 s negative cache, ClearPool + Warning when
sp_releaseapplock fails.
- Provider builds its shared state lazily (an invalid Schema no longer
throws at Resolve); Kinds is a FrozenSet; Gateway reuses the recorder's
DefaultSupportedKinds.
- Cleanup: SqlHistorianDataTypes in its own file (updater dup removed),
dead Invalidate and unused status consts deleted, named severity masks,
alarm writer brace.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Important 1: bucket offsets are now 100 ns ticks as bigint
(DATEDIFF_BIG(microsecond)*10 plus the sub-microsecond tick digits), so a
1601→9999 window no longer overflows (SQL 535) and nothing scales the interval
to nanoseconds in C#. Interval wider than the window clamps to one bucket and
the ceiling division cannot overflow. Exactness to the tick is unchanged.
Important 2 (spec §4 ruling d6afb394): a Bad previous neighbour means the time
is inside an outage — null value with that neighbour's Bad code, never
Uncertain. Usable previous + Bad next still holds the previous value Uncertain.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
SqlServerHistorianDataSource implements IHistorianDataSource over the T8 schema:
raw forward/reverse/point with the 0 = unbounded sentinel; AtTime in one statement
(TimeRow TVP + two OUTER APPLYs) with linear/stepped/no-prior rules and no
interpolation across a Bad neighbour or Empty outage marker; events with a
maxEvents+1 truncation probe and a non-null continuation point; processed
aggregates pushed down to T-SQL (SqlAggregateQueries) with nanosecond-exact
bucket edges, Calculated bits on every result, Uncertain on any non-Good input,
BadAggregateInvalidInputs for numeric aggregates over String/DateTime, a
100 000-bucket cap and HistoryAggregateNotSupportedException for the rest.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Joseph Doherty