-- arch-review 2026-08-19 P5-2 (register row-35 class): the SiteCalls list page's
-- sort key gets its own index.
--
-- SiteCallAuditRepository.QueryAsync orders (CreatedAtUtc DESC, TrackedOperationId
-- DESC), and its keyset predicate is exactly that pair. None of the existing
-- SiteCalls indexes lead unconditionally on CreatedAtUtc:
--   - IX_SiteCalls_Source_Created requires an equality on SourceSite first.
--   - IX_SiteCalls_NonTerminal / IX_SiteCalls_Terminal are each filtered to one
--     side of TerminalAtUtc.
-- So an unfiltered (or lightly filtered) page fell back to a full clustered-index
-- scan + sort. IX_SiteCalls_Created_TrackedOperationId (CreatedAtUtc DESC,
-- TrackedOperationId DESC) makes a forward scan of the index deliver rows in the
-- requested order directly, so a keyset page reads a Top-N off the index instead
-- of sorting the whole table on every page request.
--
-- SiteCalls is small enough today that a plain (offline) index build is fine. On
-- an Enterprise edition instance where the table has grown large and the Central
-- UI must stay responsive, add WITH (ONLINE = ON) to the CREATE INDEX below.
--
-- Run with QUOTED_IDENTIFIER ON. Several tables in this database carry filtered
-- indexes and persisted computed columns, and SQL Server refuses DDL/DML against
-- them with error 1934 when the session has QUOTED_IDENTIFIER OFF -- which is
-- exactly what `sqlcmd` gives you by default (pass -I, or keep this header). The
-- SETs sit in their own batch so they are in force when the statements after the
-- GO parse.
SET QUOTED_IDENTIFIER ON;
SET ANSI_NULLS ON;
GO

BEGIN TRANSACTION;
IF NOT EXISTS (
    SELECT * FROM [__EFMigrationsHistory]
    WHERE [MigrationId] = N'20260819183326_AddSiteCallsListSortIndex'
)
BEGIN
    EXEC(N'CREATE INDEX [IX_SiteCalls_Created_TrackedOperationId]
        ON [SiteCalls] ([CreatedAtUtc] DESC, [TrackedOperationId] DESC)');
END;

IF NOT EXISTS (
    SELECT * FROM [__EFMigrationsHistory]
    WHERE [MigrationId] = N'20260819183326_AddSiteCallsListSortIndex'
)
BEGIN
    INSERT INTO [__EFMigrationsHistory] ([MigrationId], [ProductVersion])
    VALUES (N'20260819183326_AddSiteCallsListSortIndex', N'10.0.7');
END;

COMMIT;
GO