-- ===================================================================================================================
-- SQLI-MEM-001: Forespørgsler venter på hukommelse
-- ===================================================================================================================
-- Regel-id:    SQLI-MEM-001
-- Titel:       Forespørgsler venter på hukommelse
-- Alvor:       High
-- Versioner:   Alle (SQL Server 2000 via master.dbo.sysperfinfo).
--
-- Hvad tjekkes, og hvorfor:
--   Om forespørgsler står i kø for at få tildelt hukommelse (RESOURCE_SEMAPHORE), før de kan starte.
--
-- Vurdering (sker i C# ud fra de indsamlede data, ikke i SQL'en, medmindre andet er nævnt):
--   Fund hvis tælleren 'Memory Grants Pending' (øjebliksværdi) > 0, eller RESOURCE_SEMAPHORE har ventet mindst 10.000
--   ms i intervallet mellem to ventetidsmålinger.
--
-- Grænseværdier (konfigurationsnøgle i agentens appsettings.json og standardværdi):
--   Pending > 0 eller >= 10.000 ms RESOURCE_SEMAPHORE (fast i koden).
--
-- Rettigheder til agentens login (se db/permissions/grant-least-privilege.sql; [agent] = agentens login):
--   GRANT VIEW SERVER STATE TO [agent];                -- SQL Server 2005-2019
--   GRANT VIEW SERVER PERFORMANCE STATE TO [agent];    -- SQL Server 2022+ (erstatter VIEW SERVER STATE)
--   GRANT VIEW SERVER SECURITY STATE TO [agent];       -- SQL Server 2022+
--   SQL Server 2000 har ikke VIEW SERVER STATE; se docs/legacy-versions.md (fx kræver DBCC SQLPERF(WAITSTATS) forhøjede rettigheder).
--
-- Data kommer fra (collector, fil : medlemmer, interval):
--   PerformanceCounterCollector
--     Fil: src/SQLInsight.Collectors/Performance/PerformanceCounterCollector.cs
--     Medlemmer: Db.StartTimeSql(version), PerformanceCounterCollector.BuildSql(dmv: true),
--     PerformanceCounterCollector.BuildSql(dmv: false)
--     Interval: 5 min som standard (SQLInsight:CollectorIntervals:performance-counters)
--     Delt script: SQL Scripts/_collectors/PerformanceCounterCollector.sql
--   WaitStatsCollector
--     Fil: src/SQLInsight.Collectors/Performance/WaitStatsCollector.cs
--     Medlemmer: Db.StartTimeSql(version), WaitStatsCollector.Sql2005, WaitStatsCollector.Sql2000
--     Interval: 5 min som standard (SQLInsight:CollectorIntervals:wait-stats)
--     Delt script: SQL Scripts/_collectors/WaitStatsCollector.sql
-- Regelkode:   src/SQLInsight.Rules/Performance/ResourceRules.cs : MemoryGrantsPendingRule.Evaluate
--
-- Read-only:   Ja: kun SELECT samt DBCC SQLPERF(WAITSTATS) (læser ventetider, SQL Server 2000),
--              SET-sessionsindstillinger. Intet ændrer data, indstillinger eller objekter.
-- Kørsel:      Kør i SSMS som agentens login (eller et login med samme rettigheder). Hver variant er sin egen batch
--              (GO); en variant for en anden SQL Server-version end din kan fejle - det er forventet.
--              Per-database-forespørgsler er vist for databasen msdb, som findes overalt: ret navnet til den
--              database, du vil se.
-- ===================================================================================================================

-- -------------------------------------------------------------------------------------------------------------------
-- Forbindelsen: Sessionsindstillinger, agenten sætter på hver forbindelse
-- -------------------------------------------------------------------------------------------------------------------

-- Variant: Alle versioner: sættes på hver forbindelse, agenten åbner
-- Kilde: SqlConnectionFactory.SessionSettings
-- Kode:  src/SQLInsight.Connectivity/SqlConnectionFactory.cs : SqlConnectionFactory.SessionSettings
SET LOCK_TIMEOUT 5000; SET DEADLOCK_PRIORITY LOW; SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
GO

-- -------------------------------------------------------------------------------------------------------------------
-- PerformanceCounterCollector: Udvalgte performance counters: memory grants, page life expectancy, forbindelser,
-- blokerede processer, batch requests og kompileringer.
-- -------------------------------------------------------------------------------------------------------------------

-- Variant: SQL Server 2008 og nyere: starttidspunkt
-- Kilde: PerformanceCounterCollector.StartTimeSql(2008+)
-- Kode:  src/SQLInsight.Collectors/Db.cs : Db.StartTimeSql(version)
SELECT (SELECT sqlserver_start_time FROM sys.dm_os_sys_info)
GO

-- Variant: SQL Server 2005: starttidspunkt
-- Kilde: PerformanceCounterCollector.StartTimeSql(2005)
-- Kode:  src/SQLInsight.Collectors/Db.cs : Db.StartTimeSql(version)
SELECT (SELECT create_date FROM sys.databases WHERE database_id = 2)
GO

-- Variant: SQL Server 2000 (legacy ODBC-sti): starttidspunkt
-- Kilde: PerformanceCounterCollector.StartTimeSql(2000)
-- Kode:  src/SQLInsight.Collectors/Db.cs : Db.StartTimeSql(version)
SELECT (SELECT login_time FROM master.dbo.sysprocesses WHERE spid = 1)
GO

-- Variant: SQL Server 2005 og nyere
-- Kilde: PerformanceCounterCollector.BuildSql(dmv)
-- Kode:  src/SQLInsight.Collectors/Performance/PerformanceCounterCollector.cs : PerformanceCounterCollector.BuildSql(dmv: true)
SELECT RTRIM(object_name), RTRIM(counter_name), CAST(cntr_value AS bigint)
FROM sys.dm_os_performance_counters
WHERE (object_name LIKE N'%Memory Manager%' AND counter_name IN (N'Memory Grants Pending', N'Memory Grants Outstanding'))
   OR (object_name LIKE N'%Buffer Manager%' AND counter_name = N'Page life expectancy')
   OR (object_name LIKE N'%General Statistics%' AND counter_name IN (N'User Connections', N'Processes blocked'))
   OR (object_name LIKE N'%SQL Statistics%' AND counter_name IN (N'Batch Requests/sec', N'SQL Compilations/sec', N'SQL Re-Compilations/sec'))
GO

-- Variant: SQL Server 2000 (legacy ODBC-sti)
-- Kilde: PerformanceCounterCollector.BuildSql(sysperfinfo)
-- Kode:  src/SQLInsight.Collectors/Performance/PerformanceCounterCollector.cs : PerformanceCounterCollector.BuildSql(dmv: false)
SELECT RTRIM(object_name), RTRIM(counter_name), CAST(cntr_value AS bigint)
FROM master.dbo.sysperfinfo
WHERE (object_name LIKE N'%Memory Manager%' AND counter_name IN (N'Memory Grants Pending', N'Memory Grants Outstanding'))
   OR (object_name LIKE N'%Buffer Manager%' AND counter_name = N'Page life expectancy')
   OR (object_name LIKE N'%General Statistics%' AND counter_name IN (N'User Connections', N'Processes blocked'))
   OR (object_name LIKE N'%SQL Statistics%' AND counter_name IN (N'Batch Requests/sec', N'SQL Compilations/sec', N'SQL Re-Compilations/sec'))
GO

-- -------------------------------------------------------------------------------------------------------------------
-- WaitStatsCollector: Kumulative ventetider. Reglerne bruger forskellen mellem to målinger; en genstart (nyt
-- starttidspunkt) nulstiller.
-- -------------------------------------------------------------------------------------------------------------------

-- Variant: SQL Server 2008 og nyere: starttidspunkt (nulstilling af kumulative tal)
-- Kilde: WaitStatsCollector.StartTimeSql(2008+)
-- Kode:  src/SQLInsight.Collectors/Db.cs : Db.StartTimeSql(version)
SELECT (SELECT sqlserver_start_time FROM sys.dm_os_sys_info)
GO

-- Variant: SQL Server 2005: starttidspunkt
-- Kilde: WaitStatsCollector.StartTimeSql(2005)
-- Kode:  src/SQLInsight.Collectors/Db.cs : Db.StartTimeSql(version)
SELECT (SELECT create_date FROM sys.databases WHERE database_id = 2)
GO

-- Variant: SQL Server 2000 (legacy ODBC-sti): starttidspunkt
-- Kilde: WaitStatsCollector.StartTimeSql(2000)
-- Kode:  src/SQLInsight.Collectors/Db.cs : Db.StartTimeSql(version)
SELECT (SELECT login_time FROM master.dbo.sysprocesses WHERE spid = 1)
GO

-- Variant: SQL Server 2005 og nyere
-- Kilde: WaitStatsCollector.Sql2005
-- Kode:  src/SQLInsight.Collectors/Performance/WaitStatsCollector.cs : WaitStatsCollector.Sql2005
SELECT wait_type, waiting_tasks_count, wait_time_ms, signal_wait_time_ms
FROM sys.dm_os_wait_stats
WHERE wait_time_ms > 0
GO

-- Variant: SQL Server 2000 (legacy ODBC-sti)
-- Kilde: WaitStatsCollector.Sql2000
-- Kode:  src/SQLInsight.Collectors/Performance/WaitStatsCollector.cs : WaitStatsCollector.Sql2000
DBCC SQLPERF(WAITSTATS) WITH NO_INFOMSGS
GO