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.
- A DateTime.MinValue start or end on DeleteRawModified is refused
BadInvalidArgument before the backend.
- Tests: anonymous without the HistoryUpdate role denied (with it allowed),
UpdateTagAttributes enabling historization sets HistoryWrite, a throwing
updater is BadInternalError, the MinValue bounds case; corrected the
test helper's comment on how the SDK base seeds unadmitted slots.
- GatewayHistorianValueWriter remarks describe the recorder's real status
capture (and that it does not persist on the gateway).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- OtOpcUaNodeManager overrides HistoryUpdateData / HistoryDeleteRawModified / HistoryDeleteAtTime,
block-bridging to the optional IHistorianDataUpdater under the shared HistoryRead batch limiter +
deadline. Insert/Replace/Update map to HistoryUpdateMode; Remove, IsDeleteModified, events and
structure data are BadHistoryOperationUnsupported. Per-item codes stitched back in request order
(MinValue SourceTimestamp => BadInvalidTimestamp, untypeable value => BadTypeMismatch); success
clears the base's pre-seeded Unsupported error.
- HistoryWrite AccessLevel bit OR-ed in for historized nodes when an updater is wired (raw + UNS);
it is dispatch-load-bearing in the SDK base. OtOpcUaSdkServer.SetHistorianDataUpdater; the hosted
service assigns it from an optional HistorianUpdaterHolder before SetSink, clears it on stop.
- AuthorizeHistoryUpdate: ACL on => scoped OpcUaOperation.HistoryUpdate decision (replaces the role
check); ACL off => #563 key re-check + new OpcUaDataPlaneRoles.HistoryUpdate role, conferred by
ApiKeyInterimRoleMapper only from a Cluster-scoped HistoryUpdate grant (WriteOperate does not).
- AdminUI ACL editor offers NodePermissions.HistoryUpdate.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Joseph Doherty