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PlanAnalyzerTests.cs
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1026 lines (848 loc) · 41.1 KB
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using PlanViewer.Core.Models;
using PlanViewer.Core.Services;
namespace PlanViewer.Core.Tests;
public class PlanAnalyzerTests
{
// ---------------------------------------------------------------
// Rule 1: Filter Operator
// ---------------------------------------------------------------
[Fact]
public void Rule01_FilterOperator_DetectedInJoinOrClausePlan()
{
var plan = PlanTestHelper.LoadAndAnalyze("join_or_clause_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Filter Operator");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("discarding rows late"));
}
// ---------------------------------------------------------------
// Rule 2: Eager Index Spool
// ---------------------------------------------------------------
[Fact]
public void Rule02_EagerIndexSpool_DetectedInLazySpoolPlan()
{
// The lazy_spool_plan also contains an Eager Index Spool (Node 4)
var plan = PlanTestHelper.LoadAndAnalyze("lazy_spool_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Eager Index Spool");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("temporary index in TempDB"));
}
[Fact]
public void Rule02_EagerIndexSpool_NotFiredForEagerTableSpool()
{
// Plan with Eager Table Spool (PhysicalOp="Table Spool", LogicalOp="Eager Spool")
// should NOT trigger the Eager Index Spool warning
var plan = PlanTestHelper.LoadAndAnalyze("eager_table_spool_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Eager Index Spool");
Assert.Empty(warnings);
}
// ---------------------------------------------------------------
// Rule 3: Serial Plan
// ---------------------------------------------------------------
[Fact]
public void Rule03_SerialPlan_MaxDOPSetToOne()
{
var plan = PlanTestHelper.LoadAndAnalyze("many_to_many_merge_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Serial Plan");
Assert.Single(warnings);
Assert.Contains("MAXDOP is set to 1", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 4: UDF Execution Timing (actual plan with UDF runtime stats)
// ---------------------------------------------------------------
[Fact]
public void Rule04_UdfExecutionTiming_DetectsUdfCpuTime()
{
var plan = PlanTestHelper.LoadAndAnalyze("udf_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "UDF Execution");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("Scalar UDF cost"));
}
// ---------------------------------------------------------------
// Rule 5: Row Estimate Mismatch
// ---------------------------------------------------------------
[Fact]
public void Rule05_RowEstimateMismatch_FalsePositivesSuppressed()
{
// This plan has estimate mismatches on Sort and Hash nodes that did not spill —
// these are false positives that should be suppressed by harm assessment.
var plan = PlanTestHelper.LoadAndAnalyze("join_or_clause_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Row Estimate Mismatch");
// All mismatches in this plan are benign (Sort/Hash with no spill, root nodes)
Assert.Empty(warnings);
}
// ---------------------------------------------------------------
// Rule 6: Scalar UDF Reference
// ---------------------------------------------------------------
[Fact]
public void Rule06_ScalarUdfReference_SuppressedWhenSerialPlanCoversIt()
{
// The udf_plan has NonParallelPlanReason = TSQLUserDefinedFunctionsNotParallelizable,
// so the Serial Plan warning already explains why the plan is serial and Rule 6
// would be redundant (per Joe's b6 feedback on #215).
var plan = PlanTestHelper.LoadAndAnalyze("udf_plan.sqlplan");
var udfWarnings = PlanTestHelper.WarningsOfType(plan, "Scalar UDF");
var serialWarnings = PlanTestHelper.WarningsOfType(plan, "Serial Plan");
Assert.Empty(udfWarnings);
Assert.NotEmpty(serialWarnings);
Assert.Contains(serialWarnings, w => w.Message.Contains("UDF"));
}
// ---------------------------------------------------------------
// Rule 7: Spill Severity Promotion
// ---------------------------------------------------------------
[Fact]
public void Rule07_SpillSeverity_PromotedToCriticalForLargeSpills()
{
var plan = PlanTestHelper.LoadAndAnalyze("spill_plan.sqlplan");
var allWarnings = PlanTestHelper.AllWarnings(plan);
var spillWarnings = allWarnings.Where(w => w.SpillDetails != null).ToList();
Assert.NotEmpty(spillWarnings);
// Spill accounts for >50% of statement time → Critical
Assert.Contains(spillWarnings, w => w.Severity == PlanWarningSeverity.Critical);
Assert.Contains(spillWarnings, w => w.Message.Contains("Operator time:"));
}
[Fact]
public void Rule07_ExchangeSpill_SeverityBasedOnWriteCount()
{
var plan = PlanTestHelper.LoadAndAnalyze("exchange_spill_plan.sqlplan");
var allWarnings = PlanTestHelper.AllWarnings(plan);
var exchangeSpills = allWarnings.Where(w =>
w.SpillDetails != null && w.SpillDetails.SpillType == "Exchange").ToList();
Assert.NotEmpty(exchangeSpills);
// 5M writes → Critical (threshold is 1M)
Assert.Contains(exchangeSpills, w => w.Severity == PlanWarningSeverity.Critical);
// Should contain actionable message about memory buffers
Assert.Contains(exchangeSpills, w => w.Message.Contains("memory buffers"));
// Actual plan → should surface operator time
Assert.Contains(exchangeSpills, w => w.Message.Contains("Operator time:"));
}
// ---------------------------------------------------------------
// Rule 8: Parallel Thread Skew
// ---------------------------------------------------------------
[Fact]
public void Rule08_ParallelSkew_NotFiredOnLowRowOperators()
{
// This plan has well-distributed parallelism (~670K rows per thread)
// and low-row operators (1 row in Gather Streams). Skew should NOT
// fire on the low-row operators — that's noise, not real skew.
var plan = PlanTestHelper.LoadAndAnalyze("non_sargable_function_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Parallel Skew");
Assert.Empty(warnings);
}
[Fact]
public void Rule08_ParallelSkew_DetectedOnHighRowScan()
{
// Eager index spool plan: Clustered Index Scan of Badges has
// 8M rows all on thread 3 — real skew worth warning about.
var plan = PlanTestHelper.LoadAndAnalyze("eager_index_spool_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Parallel Skew");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("8,042,005"));
}
// ---------------------------------------------------------------
// Rule 9a: Excessive Memory Grant
// ---------------------------------------------------------------
[Fact]
public void Rule09a_ExcessiveMemoryGrant_SmallGrantSuppressed()
{
// lazy_spool_plan has a 1 MB grant — well under the 1 GB threshold.
// The XML MemoryGrantWarning should be suppressed (not worth surfacing).
var plan = PlanTestHelper.LoadAndAnalyze("lazy_spool_plan.sqlplan");
var allWarnings = PlanTestHelper.AllWarnings(plan);
Assert.DoesNotContain(allWarnings, w =>
w.WarningType == "Memory Grant");
}
// ---------------------------------------------------------------
// Rule 9b: Memory Grant Wait
// ---------------------------------------------------------------
[Fact]
public void Rule09b_MemoryGrantWait_DetectsGrantWaitTime()
{
var plan = PlanTestHelper.LoadAndAnalyze("memory_grant_wait_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Memory Grant Wait");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("waited"));
}
// ---------------------------------------------------------------
// Rule 10: Key Lookup with Predicate
// ---------------------------------------------------------------
[Fact]
public void Rule10_KeyLookupWithPredicate_DetectsResidualPredicate()
{
var plan = PlanTestHelper.LoadAndAnalyze("key_lookup_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Key Lookup");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("INCLUDE column"));
}
// ---------------------------------------------------------------
// Rule 11: Scan With Predicate
// ---------------------------------------------------------------
[Fact]
public void Rule11_ScanWithPredicate_DetectedInJoinOrClausePlan()
{
var plan = PlanTestHelper.LoadAndAnalyze("join_or_clause_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Scan With Predicate");
Assert.NotEmpty(warnings);
}
[Fact]
public void Rule11_ScanWithPredicate_ExcludesColumnstore()
{
// Columnstore scans should NOT trigger this rule.
// When a columnstore plan is available, add a real test.
// For now, verify the helper excludes "Columnstore" in the name.
var node = new PlanNode
{
PhysicalOp = "Columnstore Index Scan",
LogicalOp = "Columnstore Index Scan",
Predicate = "some predicate"
};
// The rule checks IsRowstoreScan internally — we verify via
// the analyzer not adding a warning to a synthetic plan.
// This is a structural sanity check.
Assert.Contains("Columnstore", node.PhysicalOp);
}
// ---------------------------------------------------------------
// Rule 12: Non-SARGable Predicate — CONVERT_IMPLICIT
// ---------------------------------------------------------------
[Fact]
public void Rule12a_NonSargable_ConvertImplicit()
{
var plan = PlanTestHelper.LoadAndAnalyze("convert_implicit_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Non-SARGable Predicate");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("CONVERT_IMPLICIT"));
}
// ---------------------------------------------------------------
// Rule 12: Non-SARGable Predicate — Function Call
// ---------------------------------------------------------------
[Fact]
public void Rule12b_NonSargable_FunctionCall_Datepart()
{
var plan = PlanTestHelper.LoadAndAnalyze("non_sargable_function_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Non-SARGable Predicate");
Assert.Single(warnings);
Assert.Contains("DATEPART", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 12: Non-SARGable Predicate — ISNULL/COALESCE
// ---------------------------------------------------------------
[Fact]
public void Rule12c_NonSargable_Isnull()
{
var plan = PlanTestHelper.LoadAndAnalyze("isnull_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Non-SARGable Predicate");
Assert.Single(warnings);
Assert.Contains("ISNULL/COALESCE", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 12: Non-SARGable Predicate — Leading Wildcard LIKE
// ---------------------------------------------------------------
[Fact]
public void Rule12d_NonSargable_LeadingWildcardLike()
{
var plan = PlanTestHelper.LoadAndAnalyze("leading_wildcard_like_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Non-SARGable Predicate");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("Leading wildcard LIKE"));
}
// ---------------------------------------------------------------
// Rule 12: Non-SARGable Predicate — CASE in Predicate
// ---------------------------------------------------------------
[Fact]
public void Rule12e_NonSargable_CaseInPredicate()
{
var plan = PlanTestHelper.LoadAndAnalyze("case_predicate_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Non-SARGable Predicate");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("CASE expression"));
}
// ---------------------------------------------------------------
// Rule 13: Data Type Mismatch (GetRangeWithMismatchedTypes)
// ---------------------------------------------------------------
[Fact]
public void Rule13_DataTypeMismatch_DetectedInMismatchedPlan()
{
var plan = PlanTestHelper.LoadAndAnalyze("mismatched_data_type_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Data Type Mismatch");
Assert.Single(warnings);
Assert.Contains("Mismatched data types", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 14: Lazy Spool Ineffective
// ---------------------------------------------------------------
[Fact]
public void Rule14_LazySpoolIneffective_SkipsLazyIndexSpools()
{
// Lazy Index Spools cache by correlated parameter value (like a hash table)
// so rebind/rewind counts are unreliable — Rule 14 should not fire.
// See https://www.sql.kiwi/2025/02/lazy-index-spool/
var plan = PlanTestHelper.LoadAndAnalyze("lazy_spool_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Lazy Spool Ineffective");
Assert.Empty(warnings);
}
// ---------------------------------------------------------------
// Rule 15: Join OR Clause
// ---------------------------------------------------------------
[Fact]
public void Rule15_JoinOrClause_DetectsConcatenationWithConstantScans()
{
var plan = PlanTestHelper.LoadAndAnalyze("join_or_clause_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Join OR Clause");
Assert.Single(warnings);
Assert.Contains("OR in a join predicate", warnings[0].Message);
Assert.Contains("UNION ALL", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 16: Nested Loops High Executions
// ---------------------------------------------------------------
[Fact]
public void Rule16_NestedLoopsHighExecutions_DetectedInJoinOrClausePlan()
{
var plan = PlanTestHelper.LoadAndAnalyze("join_or_clause_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Nested Loops High Executions");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Severity == PlanWarningSeverity.Critical);
}
// ---------------------------------------------------------------
// Rule 17: Many-to-Many Merge Join
// ---------------------------------------------------------------
[Fact]
public void Rule17_ManyToManyMergeJoin_DetectsWorktable()
{
var plan = PlanTestHelper.LoadAndAnalyze("many_to_many_merge_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Many-to-Many Merge Join");
Assert.Single(warnings);
Assert.Contains("worktable", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 18: Compile Memory Exceeded
// ---------------------------------------------------------------
[Fact]
public void Rule18_CompileMemoryExceeded_DetectsEarlyAbort()
{
var plan = PlanTestHelper.LoadAndAnalyze("compile_memory_exceeded_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Compile Memory Exceeded");
Assert.Single(warnings);
Assert.Equal(PlanWarningSeverity.Critical, warnings[0].Severity);
}
// ---------------------------------------------------------------
// Rule 19: High Compile CPU
// ---------------------------------------------------------------
[Fact]
public void Rule19_HighCompileCpu_DetectsExpensiveCompilation()
{
var plan = PlanTestHelper.LoadAndAnalyze("convert_implicit_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "High Compile CPU");
Assert.Single(warnings);
Assert.Contains("CPU just to compile", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 20: Local Variables
// ---------------------------------------------------------------
[Fact]
public void Rule20_LocalVariables_DetectsUnsnifffedParameters()
{
var plan = PlanTestHelper.LoadAndAnalyze("local_variable_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Local Variables");
Assert.Single(warnings);
Assert.Contains("@date", warnings[0].Message);
Assert.Contains("density estimates", warnings[0].Message);
}
// Rule 21 (CTE Multiple References) removed per Joe's #215 feedback — actual
// plans show time directly, no need to guess from statement-text patterns.
// ---------------------------------------------------------------
// Rule 22: Table Variable
// ---------------------------------------------------------------
[Fact]
public void Rule22_TableVariable_DetectsAtSignInObjectName()
{
var plan = PlanTestHelper.LoadAndAnalyze("table_variable_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Table Variable");
// Node-level + statement-level warnings
Assert.True(warnings.Count >= 2);
Assert.Contains(warnings, w => w.Message.Contains("lack column-level statistics"));
// Statement-level stats warning
var stmtWarnings = PlanTestHelper.FirstStatement(plan).PlanWarnings
.Where(w => w.WarningType == "Table Variable").ToList();
Assert.Contains(stmtWarnings, w => w.Message.Contains("lack column-level statistics"));
}
// ---------------------------------------------------------------
// Rule 23: Table-Valued Function
// ---------------------------------------------------------------
[Fact]
public void Rule23_TableValuedFunction_DetectsTvfOperator()
{
var plan = PlanTestHelper.LoadAndAnalyze("tvf_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Table-Valued Function");
Assert.Single(warnings);
Assert.Contains("GetTopPosts", warnings[0].Message);
}
// ---------------------------------------------------------------
// Rule 24: Top Above Scan
// ---------------------------------------------------------------
[Fact]
public void Rule24_TopAboveScan_OnlyFiresOnInnerSideOfNestedLoops()
{
// Plan: SELECT TOP 1 ... WHERE NOT EXISTS (SELECT ... FROM Votes)
// Node 0: Top (standalone SELECT TOP) — should NOT fire
// Node 1: Nested Loops (Left Anti Semi Join)
// Node 2: Clustered Index Scan (outer)
// Node 4: Top (inner side) — SHOULD fire
// Node 5: Clustered Index Scan (inner scan with predicate)
var plan = PlanTestHelper.LoadAndAnalyze("top_above_scan_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Top Above Scan");
Assert.Single(warnings);
Assert.Contains("Clustered Index Scan", warnings[0].Message);
Assert.Contains("inner side of Nested Loops", warnings[0].Message);
Assert.Contains("residual predicate", warnings[0].Message);
}
// ---------------------------------------------------------------
// Large Memory Grant (sort/hash guidance)
// ---------------------------------------------------------------
[Fact]
public void LargeMemoryGrant_DoesNotWarnBelowOneGB()
{
// join_or_clause_plan has a ~451 MB grant — should not trigger at 1 GB threshold
var plan = PlanTestHelper.LoadAndAnalyze("join_or_clause_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Large Memory Grant");
Assert.Empty(warnings);
}
// ---------------------------------------------------------------
// Rule 26: Row Goal (Informational)
// ---------------------------------------------------------------
[Fact]
public void Rule26_RowGoal_DetectedWhenEstimateReduced()
{
var plan = PlanTestHelper.LoadAndAnalyze("row_goal_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Row Goal");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Severity == PlanWarningSeverity.Info);
Assert.Contains(warnings, w => w.Message.Contains("2,500,000"));
}
// ---------------------------------------------------------------
// Rule 10: RID Lookup (heap table)
// ---------------------------------------------------------------
[Fact]
public void Rule10_RidLookup_DetectedOnHeapTable()
{
var plan = PlanTestHelper.LoadAndAnalyze("rid_lookup_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "RID Lookup");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("heap"));
}
// ---------------------------------------------------------------
// Rule 27: OPTIMIZE FOR UNKNOWN
// ---------------------------------------------------------------
[Fact]
public void Rule27_OptimizeForUnknown_DetectedInStatementText()
{
var plan = PlanTestHelper.LoadAndAnalyze("optimize_for_unknown_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Optimize For Unknown");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("density estimates"));
}
// ---------------------------------------------------------------
// Rule 29: Implicit Conversion — Seek Plan upgrade
// ---------------------------------------------------------------
[Fact]
public void Rule29_ImplicitConvertSeekPlan_UpgradedToCritical()
{
var plan = PlanTestHelper.LoadAndAnalyze("implicit_convert_seek_plan.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Implicit Conversion");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Severity == PlanWarningSeverity.Critical);
Assert.Contains(warnings, w => w.Message.Contains("prevented an index seek"));
}
// Rules 25 and 31 were removed — CPU:Elapsed ratio is shown in the runtime
// summary instead, and wait stats speak for themselves.
// ---------------------------------------------------------------
// Rule 28: NOT IN with Nullable Column (Row Count Spool)
// ---------------------------------------------------------------
[Fact]
public void Rule28_RowCountSpool_DetectsNotInWithNullableColumn()
{
// row-count-spool-slow: Row Count Spool with ~24M estimated rewinds,
// NOT IN pattern with nullable UserId column
var plan = PlanTestHelper.LoadAndAnalyze("row-count-spool-slow.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "NOT IN with Nullable Column");
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Message.Contains("NOT IN"));
Assert.Contains(warnings, w => w.Message.Contains("NOT EXISTS"));
}
// ---------------------------------------------------------------
// Rule 30: Missing Index Quality (Wide Index / Low Impact)
// ---------------------------------------------------------------
[Fact]
public void Rule30_MissingIndexQuality_DetectsWideOrLowImpact()
{
// slow-multi-seek has missing index suggestions — verify quality analysis runs
var plan = PlanTestHelper.LoadAndAnalyze("slow-multi-seek.sqlplan");
var stmt = PlanTestHelper.FirstStatement(plan);
// If there are missing indexes, the quality rules should evaluate them
if (stmt.MissingIndexes.Count > 0)
{
var allWarnings = PlanTestHelper.AllWarnings(plan);
var indexWarnings = allWarnings.Where(w =>
w.WarningType == "Low Impact Index" ||
w.WarningType == "Wide Index Suggestion" ||
w.WarningType == "Duplicate Index Suggestions").ToList();
// At minimum, the rule ran without errors
Assert.True(true);
}
}
// ---------------------------------------------------------------
// Seek Predicate Parsing
// ---------------------------------------------------------------
[Fact]
public void SeekPredicateParsing_FormatsColumnEqualsValue()
{
// slow-multi-seek: Index Seek with SeekPredicateNew containing
// SeekKeys with Prefix ranges (PostTypeId = value patterns)
var plan = PlanTestHelper.LoadAndAnalyze("slow-multi-seek.sqlplan");
var stmt = PlanTestHelper.FirstStatement(plan);
Assert.NotNull(stmt.RootNode);
// Find the Index Seek node
var seekNode = FindNodeByOp(stmt.RootNode, "Index Seek");
Assert.NotNull(seekNode);
Assert.NotNull(seekNode!.SeekPredicates);
// Should have Column = Value format, not bare scalar values
Assert.Contains("=", seekNode.SeekPredicates);
}
// ---------------------------------------------------------------
// Parameter Sniffing Detection (compiled vs runtime value mismatch)
// ---------------------------------------------------------------
[Fact]
public void ParameterParsing_DetectsCompiledVsRuntimeMismatch()
{
// param-sniffing-posttypeid2: compiled for @VoteTypeId=(4), executed with (2)
var plan = PlanTestHelper.LoadAndAnalyze("param-sniffing-posttypeid2.sqlplan");
var stmt = PlanTestHelper.FirstStatement(plan);
var param = stmt.Parameters.FirstOrDefault(p => p.Name == "@VoteTypeId");
Assert.NotNull(param);
Assert.NotEqual(param!.CompiledValue, param.RuntimeValue);
}
// ---------------------------------------------------------------
// PSPO / Dispatcher Detection
// ---------------------------------------------------------------
[Fact]
public void PspoParsing_DetectsDispatcherElement()
{
// pspo-example: Parameter Sensitive Plan Optimization with Dispatcher
var plan = PlanTestHelper.LoadAndAnalyze("pspo-example.sqlplan");
var stmt = PlanTestHelper.FirstStatement(plan);
Assert.NotNull(stmt.Dispatcher);
Assert.NotEmpty(stmt.Dispatcher!.ParameterSensitivePredicates);
}
// ---------------------------------------------------------------
// Spill Detection on Actual Plan
// ---------------------------------------------------------------
[Fact]
public void SpillDetection_MultipleSpillsInParallelPlan()
{
// excellent-parallel-spill: 3 SpillToTempDb warnings in a DOP 4 plan
var plan = PlanTestHelper.LoadAndAnalyze("excellent-parallel-spill.sqlplan");
var allWarnings = PlanTestHelper.AllWarnings(plan);
var spillWarnings = allWarnings.Where(w => w.SpillDetails != null).ToList();
Assert.NotEmpty(spillWarnings);
}
// ---------------------------------------------------------------
// Parallel Skew Detection — Effective Parallelism
// ---------------------------------------------------------------
[Fact]
public void ParallelSkew_DetectedInSkewedPlan()
{
// parallel-skew: DOP 4 with thread distribution skew on scan
var plan = PlanTestHelper.LoadAndAnalyze("parallel-skew.sqlplan");
var warnings = PlanTestHelper.WarningsOfType(plan, "Parallel Skew");
// Whether skew fires depends on the distribution in this plan.
// The important thing is the plan parses and analyzes without error.
// If skew is detected, it should have a meaningful message.
foreach (var w in warnings)
{
Assert.Contains("rows", w.Message);
}
}
// ---------------------------------------------------------------
// Helper
// ---------------------------------------------------------------
private static PlanNode? FindNodeByOp(PlanNode root, string physicalOp)
{
if (root.PhysicalOp == physicalOp) return root;
foreach (var child in root.Children)
{
var found = FindNodeByOp(child, physicalOp);
if (found != null) return found;
}
return null;
}
// ---------------------------------------------------------------
// NoJoinPredicate: verify it flows through to TextFormatter output
// ---------------------------------------------------------------
[Fact]
public void NoJoinPredicate_AppearsInTextFormatterOutput()
{
var plan = PlanTestHelper.LoadAndAnalyze("missing-join-predicate.sqlplan");
var analysis = PlanViewer.Core.Output.ResultMapper.Map(plan, "file");
var text = PlanViewer.Core.Output.TextFormatter.Format(analysis);
Assert.Contains("[Warning]", text);
Assert.Contains("No Join Predicate", text);
Assert.Contains("often misleading", text);
}
// ---------------------------------------------------------------
// Issue #178: Warning improvement verification (test1.sqlplan)
// ---------------------------------------------------------------
[Fact]
public void Issue178_5_SerialPlanSuppressedOnTrivialStatement()
{
// Statement 1 is a trivial variable assignment (cost ~0.000001) — no Serial Plan warning
// Uses private test plan from .internal (not committed to git)
var plan = PlanTestHelper.LoadFromInternal("test1.sqlplan");
if (plan == null) return; // Skip if plan not available
var stmt1 = plan.Batches.SelectMany(b => b.Statements).First();
Assert.True(stmt1.StatementSubTreeCost < 0.01, "Statement 1 should be trivial cost");
Assert.DoesNotContain(stmt1.PlanWarnings, w => w.WarningType == "Serial Plan");
}
[Fact]
public void Issue178_9_JoinOrNotTriggeredByMergeInterval()
{
// Statement 8 has a Merge Interval inside a NOT IN anti-semi join — not a genuine OR expansion
var plan = PlanTestHelper.LoadFromInternal("test1.sqlplan");
if (plan == null) return;
var stmt8 = plan.Batches.SelectMany(b => b.Statements).ElementAt(7);
var allNodeWarnings = PlanTestHelper.AllNodeWarnings(stmt8);
Assert.DoesNotContain(allNodeWarnings, w => w.WarningType == "Join OR Clause");
}
[Fact]
public void Issue178_12_RowGoal1to1Suppressed()
{
// Row Goal "1 to 1 (1x reduction)" should not fire — requires >= 2x reduction
var plan = PlanTestHelper.LoadFromInternal("test1.sqlplan");
if (plan == null) return;
var allWarnings = PlanTestHelper.AllWarnings(plan);
Assert.DoesNotContain(allWarnings, w =>
w.WarningType == "Row Goal" && w.Message.Contains("1x reduction"));
}
[Fact]
public void Issue178_6_LocalVariableSuppressedOnTrivialStatement()
{
// Statement 1 is a trivial variable assignment (cost ~0.000001) — no Local Variables warning
var plan = PlanTestHelper.LoadFromInternal("test1.sqlplan");
if (plan == null) return;
var stmt1 = plan.Batches.SelectMany(b => b.Statements).First();
Assert.True(stmt1.StatementSubTreeCost < 0.01);
Assert.DoesNotContain(stmt1.PlanWarnings, w => w.WarningType == "Local Variables");
}
[Fact]
public void Issue178_7_FilterSuppressedOnTrivialChildIO()
{
// Statement 5 has a Filter with 19 reads and 0-1ms child — should be suppressed
var plan = PlanTestHelper.LoadFromInternal("test1.sqlplan");
if (plan == null) return;
var stmt5 = plan.Batches.SelectMany(b => b.Statements).ElementAt(4);
var filterWarnings = PlanTestHelper.AllNodeWarnings(stmt5)
.Where(w => w.WarningType == "Filter Operator").ToList();
Assert.Empty(filterWarnings);
}
// ---------------------------------------------------------------
// Wait stats cross-cutting integration
// ---------------------------------------------------------------
private static List<WaitStatInfo> IoWaits(long ms = 2000) => new()
{
new WaitStatInfo { WaitType = "PAGEIOLATCH_SH", WaitTimeMs = ms, WaitCount = 50 },
new WaitStatInfo { WaitType = "ASYNC_NETWORK_IO", WaitTimeMs = 100, WaitCount = 10 }
};
private static List<WaitStatInfo> CpuWaits(long ms = 4000) => new()
{
new WaitStatInfo { WaitType = "SOS_SCHEDULER_YIELD", WaitTimeMs = ms, WaitCount = 5000 },
new WaitStatInfo { WaitType = "ASYNC_NETWORK_IO", WaitTimeMs = 100, WaitCount = 10 }
};
private static ParsedPlan BuildSyntheticPlan(PlanStatement stmt)
{
var plan = new ParsedPlan();
plan.Batches.Add(new PlanBatch { Statements = { stmt } });
return plan;
}
[Fact]
public void WaitStats_Rule11_ScanWithIoWaitsElevatedToCritical()
{
// Scan at 60% cost + I/O waits → elevated to Critical (normally needs 90%)
var scan = new PlanNode
{
NodeId = 0, PhysicalOp = "Clustered Index Scan", LogicalOp = "Clustered Index Scan",
Predicate = "[col1] = @p1",
EstimatedTotalSubtreeCost = 6.0
};
var stmt = new PlanStatement
{
RootNode = scan,
StatementSubTreeCost = 10.0,
WaitStats = IoWaits()
};
var plan = BuildSyntheticPlan(stmt);
PlanAnalyzer.Analyze(plan);
var warnings = PlanTestHelper.AllNodeWarnings(stmt)
.Where(w => w.WarningType == "Scan With Predicate").ToList();
Assert.NotEmpty(warnings);
Assert.Contains(warnings, w => w.Severity == PlanWarningSeverity.Critical);
}
[Fact]
public void WaitStats_Rule11_ScanWithoutIoWaitsStaysWarning()
{
// Same scan at 60% cost but no I/O waits → stays Warning
var scan = new PlanNode
{
NodeId = 0, PhysicalOp = "Clustered Index Scan", LogicalOp = "Clustered Index Scan",
Predicate = "[col1] = @p1",
EstimatedTotalSubtreeCost = 6.0
};
var stmt = new PlanStatement
{
RootNode = scan,
StatementSubTreeCost = 10.0
};
var plan = BuildSyntheticPlan(stmt);
PlanAnalyzer.Analyze(plan);
var warnings = PlanTestHelper.AllNodeWarnings(stmt)
.Where(w => w.WarningType == "Scan With Predicate").ToList();
Assert.NotEmpty(warnings);
Assert.All(warnings, w => Assert.Equal(PlanWarningSeverity.Warning, w.Severity));
}
[Fact]
public void WaitStats_Rule11_CpuWaitsDoNotElevateSeverity()
{
// CPU waits (SOS_SCHEDULER_YIELD) are not I/O — should NOT elevate at 60% cost
var scan = new PlanNode
{
NodeId = 0, PhysicalOp = "Clustered Index Scan", LogicalOp = "Clustered Index Scan",
Predicate = "[col1] = @p1",
EstimatedTotalSubtreeCost = 6.0
};
var stmt = new PlanStatement
{
RootNode = scan,
StatementSubTreeCost = 10.0,
WaitStats = CpuWaits()
};
var plan = BuildSyntheticPlan(stmt);
PlanAnalyzer.Analyze(plan);
var warnings = PlanTestHelper.AllNodeWarnings(stmt)
.Where(w => w.WarningType == "Scan With Predicate").ToList();
Assert.NotEmpty(warnings);
Assert.All(warnings, w => Assert.Equal(PlanWarningSeverity.Warning, w.Severity));
}
#region Rule 38 — Standard Edition DOP Limitation
private static PlanStatement BuildBatchModeDop2Statement()
{
var batchNode = new PlanNode
{
NodeId = 1,
PhysicalOp = "Hash Match",
LogicalOp = "Inner Join",
ExecutionMode = "Batch"
};
var root = new PlanNode
{
NodeId = 0,
PhysicalOp = "Columnstore Index Scan",
LogicalOp = "Columnstore Index Scan",
ExecutionMode = "Batch",
Children = { batchNode }
};
return new PlanStatement
{
RootNode = root,
DegreeOfParallelism = 2,
StatementSubTreeCost = 10.0
};
}
[Fact]
public void Rule38_StandardEdition_Dop2_BatchMode_MaxDopAbove2_EmitsWarning()
{
var stmt = BuildBatchModeDop2Statement();
var plan = BuildSyntheticPlan(stmt);
var metadata = new ServerMetadata
{
Edition = "Standard Edition (64-bit)",
MaxDop = 8
};
PlanAnalyzer.Analyze(plan, serverMetadata: metadata);
var warnings = stmt.PlanWarnings
.Where(w => w.WarningType == "Standard Edition DOP Limitation").ToList();
Assert.Single(warnings);
Assert.Equal(PlanWarningSeverity.Warning, warnings[0].Severity);
Assert.Contains("MAXDOP is set to 8", warnings[0].Message);
}
[Fact]
public void Rule38_StandardEdition_Dop2_BatchMode_MaxDop2_NoWarning()
{
// MAXDOP=2 means the limitation isn't biting — DOP matches MAXDOP
var stmt = BuildBatchModeDop2Statement();
var plan = BuildSyntheticPlan(stmt);
var metadata = new ServerMetadata
{
Edition = "Standard Edition (64-bit)",
MaxDop = 2
};
PlanAnalyzer.Analyze(plan, serverMetadata: metadata);
var warnings = stmt.PlanWarnings
.Where(w => w.WarningType == "Standard Edition DOP Limitation").ToList();
Assert.Empty(warnings);
}
[Fact]
public void Rule38_NoServerMetadata_Dop2_BatchMode_EmitsInfo()
{
var stmt = BuildBatchModeDop2Statement();
var plan = BuildSyntheticPlan(stmt);
PlanAnalyzer.Analyze(plan);
var warnings = stmt.PlanWarnings
.Where(w => w.WarningType == "Standard Edition DOP Limitation").ToList();
Assert.Single(warnings);
Assert.Equal(PlanWarningSeverity.Info, warnings[0].Severity);
}
[Fact]
public void Rule38_ServerMetadataWithNullEdition_Dop2_BatchMode_EmitsInfo()
{
// Edge case: serverMetadata present but Edition is null (collection failure)
var stmt = BuildBatchModeDop2Statement();
var plan = BuildSyntheticPlan(stmt);
var metadata = new ServerMetadata
{
Edition = null,
MaxDop = 8
};
PlanAnalyzer.Analyze(plan, serverMetadata: metadata);
var warnings = stmt.PlanWarnings
.Where(w => w.WarningType == "Standard Edition DOP Limitation").ToList();
Assert.Single(warnings);
Assert.Equal(PlanWarningSeverity.Info, warnings[0].Severity);
}
[Fact]
public void Rule38_StandardEdition_Dop2_BatchMode_MaxDop2QueryHint_NoWarning()
{
// User explicitly set OPTION (MAXDOP 2) — DOP cap is intentional, not the SE limit
var stmt = BuildBatchModeDop2Statement();
stmt.StatementText = "SELECT * FROM dbo.Fact OPTION (MAXDOP 2)";
var plan = BuildSyntheticPlan(stmt);
var metadata = new ServerMetadata
{