-- ===================================================================================================================
-- SQLI-PLAN-004: Sorteringer og hash joins spilder til tempdb
-- ===================================================================================================================
-- Regel-id:    SQLI-PLAN-004
-- Titel:       Sorteringer og hash joins spilder til tempdb
-- Alvor:       Medium
-- Versioner:   SQL Server 2016 SP2 / 2017 CU3 og nyere (total_spills i sys.dm_exec_query_stats). Ældre: "tjek
--              manuelt".
--
-- Hvad tjekkes, og hvorfor:
--   Om sorteringer og hash joins i en tung forespørgsel spilder til tempdb.
--
-- Vurdering (sker i C# ud fra de indsamlede data, ikke i SQL'en, medmindre andet er nævnt):
--   Fund hvis total_spills / execution_count >= 1.024 sider (ca. 8 MB) pr. udførelse. Højst 10 fund.
--
-- Grænseværdier (konfigurationsnøgle i agentens appsettings.json og standardværdi):
--   1.024 sider pr. udførelse (SpillRule.MinSpillPagesPerExecution, 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+
--
-- Data kommer fra (collector, fil : medlemmer, interval):
--   PlanAnalysisCollector
--     Fil: src/SQLInsight.Collectors/Performance/PlanAnalysisCollector.cs
--     Medlemmer: PlanAnalysisCollector.BuildSql(memoryColumns: true, queryHash: true),
--     PlanAnalysisCollector.BuildSql(memoryColumns: false, queryHash: true),
--     PlanAnalysisCollector.BuildSql(memoryColumns: false, queryHash: false)
--     Interval: 30 min som standard (SQLInsight:CollectorIntervals:plan-analysis)
--     Delt script: SQL Scripts/_collectors/PlanAnalysisCollector.sql
-- Regelkode:   src/SQLInsight.Rules/Performance/PlanRules.cs : SpillRule
--
-- Read-only:   Ja: kun SELECT samt 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

-- -------------------------------------------------------------------------------------------------------------------
-- PlanAnalysisCollector: De 50 sætninger med mest CPU det seneste døgn og deres cachede planer (som tekst), som
-- analyseres i C# (ShowplanAnalyzer).
-- -------------------------------------------------------------------------------------------------------------------

-- Variant: SQL Server 2016 SP2 / 2017 CU3 og nyere (med spill- og memory grant-kolonner)
-- Kilde: PlanAnalysisCollector.BuildSql(2016 SP2+)
-- Kode:  src/SQLInsight.Collectors/Performance/PlanAnalysisCollector.cs : PlanAnalysisCollector.BuildSql(memoryColumns: true, queryHash: true)
WITH top_statements AS (
    SELECT TOP (50) qs.*
    FROM sys.dm_exec_query_stats qs
    WHERE qs.last_execution_time >= DATEADD(hour, -24, GETDATE())
    ORDER BY qs.total_worker_time DESC
)
SELECT CONVERT(varchar(20), qs.query_hash, 1),
       DB_NAME(CONVERT(int, pa.value)),
       LEFT(SUBSTRING(t.text, qs.statement_start_offset / 2 + 1,
            (CASE WHEN qs.statement_end_offset = -1 THEN DATALENGTH(t.text) ELSE qs.statement_end_offset END - qs.statement_start_offset) / 2 + 1), 4000),
       qs.execution_count, qs.total_worker_time, qs.total_elapsed_time, qs.total_logical_reads,
       qs.total_spills, qs.total_grant_kb, qs.total_used_grant_kb,
       qs.last_execution_time,
       tp.query_plan
FROM top_statements qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) t
OUTER APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) tp
OUTER APPLY (SELECT value FROM sys.dm_exec_plan_attributes(qs.plan_handle) WHERE attribute = N'dbid') pa
ORDER BY qs.total_worker_time DESC;
GO

-- Variant: SQL Server 2008 – 2016 SP1 og 2017 før CU3
-- Kilde: PlanAnalysisCollector.BuildSql(2008)
-- Kode:  src/SQLInsight.Collectors/Performance/PlanAnalysisCollector.cs : PlanAnalysisCollector.BuildSql(memoryColumns: false, queryHash: true)
WITH top_statements AS (
    SELECT TOP (50) qs.*
    FROM sys.dm_exec_query_stats qs
    WHERE qs.last_execution_time >= DATEADD(hour, -24, GETDATE())
    ORDER BY qs.total_worker_time DESC
)
SELECT CONVERT(varchar(20), qs.query_hash, 1),
       DB_NAME(CONVERT(int, pa.value)),
       LEFT(SUBSTRING(t.text, qs.statement_start_offset / 2 + 1,
            (CASE WHEN qs.statement_end_offset = -1 THEN DATALENGTH(t.text) ELSE qs.statement_end_offset END - qs.statement_start_offset) / 2 + 1), 4000),
       qs.execution_count, qs.total_worker_time, qs.total_elapsed_time, qs.total_logical_reads,
       CAST(NULL AS bigint), CAST(NULL AS bigint), CAST(NULL AS bigint),
       qs.last_execution_time,
       tp.query_plan
FROM top_statements qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) t
OUTER APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) tp
OUTER APPLY (SELECT value FROM sys.dm_exec_plan_attributes(qs.plan_handle) WHERE attribute = N'dbid') pa
ORDER BY qs.total_worker_time DESC;
GO

-- Variant: SQL Server 2005 SP2 og nyere 2005-builds
-- Kilde: PlanAnalysisCollector.BuildSql(2005)
-- Kode:  src/SQLInsight.Collectors/Performance/PlanAnalysisCollector.cs : PlanAnalysisCollector.BuildSql(memoryColumns: false, queryHash: false)
WITH top_statements AS (
    SELECT TOP (50) qs.*
    FROM sys.dm_exec_query_stats qs
    WHERE qs.last_execution_time >= DATEADD(hour, -24, GETDATE())
    ORDER BY qs.total_worker_time DESC
)
SELECT sys.fn_varbintohexstr(qs.sql_handle) + ':' + CAST(qs.statement_start_offset AS varchar(12)) + ':' + CAST(qs.statement_end_offset AS varchar(12)),
       DB_NAME(CONVERT(int, pa.value)),
       LEFT(SUBSTRING(t.text, qs.statement_start_offset / 2 + 1,
            (CASE WHEN qs.statement_end_offset = -1 THEN DATALENGTH(t.text) ELSE qs.statement_end_offset END - qs.statement_start_offset) / 2 + 1), 4000),
       qs.execution_count, qs.total_worker_time, qs.total_elapsed_time, qs.total_logical_reads,
       CAST(NULL AS bigint), CAST(NULL AS bigint), CAST(NULL AS bigint),
       qs.last_execution_time,
       tp.query_plan
FROM top_statements qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) t
OUTER APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) tp
OUTER APPLY (SELECT value FROM sys.dm_exec_plan_attributes(qs.plan_handle) WHERE attribute = N'dbid') pa
ORDER BY qs.total_worker_time DESC;
GO