-- ===================================================================================================================
-- Collector: PerformanceCounterCollector ("performance-counters")
-- ===================================================================================================================
-- Hvad:        Udvalgte performance counters: memory grants, page life expectancy, forbindelser, blokerede processer,
--              batch requests og kompileringer.
-- Fil:         src/SQLInsight.Collectors/Performance/PerformanceCounterCollector.cs
-- Interval:    5 min som standard (SQLInsight:CollectorIntervals:performance-counters)
-- Versioner:   Alle (SQL Server 2000 og nyere)
--
-- 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).
--
-- Bruges af:   SQLI-MEM-001, SQLI-ANOM-001
-- Read-only:   Ja: kun SELECT samt SET-sessionsindstillinger. Intet ændrer data, indstillinger eller objekter.
-- Kørsel:     Kør i SSMS som agentens login. Hver variant er sin egen batch (GO); en variant for en anden SQL Server-version
--             end din kan fejle - det er forventet. Agenten kører altid med sessionsindstillingerne i _collectors/InstanceProbe.sql.
-- ===================================================================================================================

-- 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