Performance Studio

A cross-platform SQL Server execution plan analyzer with built-in MCP server for AI-assisted analysis. Parses .sqlplan XML, identifies performance problems, suggests missing indexes, and provides actionable warnings — from the command line or a desktop GUI.

Built for developers and DBAs who want fast, automated plan analysis without clicking through SSMS.

Screenshots

Query Editor

Write queries with syntax highlighting and SQL keyword completion, connect to any SQL Server, and capture plans with one click.

Actual Execution Plan with Plan Insights

Graphical plan tree with SSMS-style operator icons, cost percentages, row counts, and warning badges. The Plan Insights panel shows runtime summary, missing indexes, parameters, and wait stats at a glance.

Multi-Statement Navigation

Navigate stored procedures and batches with multiple statements. Click any statement in the grid to jump to its plan. Plan Insights shows parameters with compiled vs runtime values.

Operator Tooltip and Properties

Hover over any operator for a detailed tooltip with costs, rows, I/O, timing, parallelism, and warnings. Click to open the full properties panel with per-thread timing, predicates, and more.

Advice for Humans

One-click text report with server context, warnings, wait stats, and expensive operators — ready to read or share.

Plan Comparison

Side-by-side comparison of two plans showing cost, runtime, I/O, memory, and wait stat differences.

Query Store Integration

Fetch top queries by CPU, duration, logical reads, physical reads, writes, memory, or executions from Query Store and load their plans directly into the analyzer.

Minimap and colored links by accuracy ratio divergence

The minimap provides a high-level overview of the entire plan, allowing you to quickly navigate to areas of interest. Colored links between operators indicate accuracy ratio divergence, helping you identify where estimates are most off from actuals.

MCP Integration

Ask Claude Code to analyze loaded plans, identify warnings, suggest indexes, and compare plans — all through the built-in MCP server.

What It Does

Feed it a query plan and it tells you what's wrong:

• Large memory grants — flags queries hoarding memory they don't use
• Row estimate mismatches — finds operators where estimates are 10x+ off from actuals
• Missing indexes — extracts SQL Server's index suggestions with ready-to-run CREATE statements
• Hash, sort, and exchange spills — identifies operators spilling to TempDB with severity based on volume
• Parallel skew — detects threads doing all the work while others sit idle
• Scan predicates — warns when scans filter rows with residual predicates
• Key and RID lookups — flags lookups back to the base table, distinguishes heaps from clustered indexes
• Late filters — finds Filter operators discarding rows deep in the plan
• Nested loop concerns — flags high-execution nested loops that might be better as hash joins
• Parameter sniffing — compares compiled vs runtime parameter values
• Scalar UDFs — warns about T-SQL and CLR scalar functions in execution paths
• Implicit conversions — detects type mismatches, upgrades severity when a seek plan is prevented
• Anti-patterns — OPTIMIZE FOR UNKNOWN, NOT IN with nullable columns, leading wildcards, function-wrapped predicates, and more

Each warning includes severity (Info, Warning, or Critical), the operator node ID, and enough context to act on immediately.

Prerequisites

• .NET 8 SDK (required to build and run)
• SQL Server instance (optional — only needed for live plan capture; file analysis works without one)
• Docker (optional — macOS/Linux users can run SQL Server locally via Docker)

Download

Pre-built binaries are available on the Releases page:

Platform	Download
Windows (x64)	PerformanceStudio-win-x64.zip
macOS (Apple Silicon)	PerformanceStudio-osx-arm64.zip
macOS (Intel)	PerformanceStudio-osx-x64.zip
Linux (x64)	PerformanceStudio-linux-x64.zip

These are self-contained — no .NET SDK required. Extract the zip and run.

macOS note: macOS may block the app because it isn't signed with an Apple Developer certificate. If you see a warning that the app "can't be opened," run this after extracting:

xattr -cr PerformanceStudio.app

Then open the app normally.

Build from Source

Clone and build:

git clone https://github.com/erikdarlingdata/PerformanceStudio.git
cd PerformanceStudio
dotnet build

To verify the build:

dotnet test tests/PlanViewer.Core.Tests    # 37 tests should pass
dotnet run --project src/PlanViewer.Cli -- analyze --help

Quick Start

Analyze an existing .sqlplan file

If you already have a .sqlplan file (saved from SSMS, Azure Data Studio, or another tool):

# JSON output (default) — full operator tree, suitable for automation
planview analyze my_query.sqlplan

# Human-readable text output
planview analyze my_query.sqlplan --output text

# Text output, warnings and missing indexes only (skip operator tree)
planview analyze my_query.sqlplan --output text --warnings-only

Capture and analyze plans from a live server

Connect to a SQL Server instance, run queries, and capture their execution plans automatically.

Quickest way — pass credentials directly:

# Capture an actual execution plan (the query WILL run)
planview analyze --server sql2022 --database AdventureWorks \
    --login sa --password YourPassword \
    --query "SELECT * FROM Sales.SalesOrderHeader WHERE OrderDate > '2024-01-01'" \
    --trust-cert --output-dir ./results/

# Capture an estimated plan (safe for production — query is NOT executed)
planview analyze --server sql2022 --database AdventureWorks \
    --login sa --password YourPassword \
    --query "SELECT * FROM Sales.SalesOrderHeader" \
    --estimated --trust-cert --output-dir ./results/

Using a .env file — drop a .env in your working directory to avoid repeating connection details:

# .env
PLANVIEW_SERVER=sql2022
PLANVIEW_DATABASE=AdventureWorks
PLANVIEW_LOGIN=sa
PLANVIEW_PASSWORD=YourPassword
PLANVIEW_TRUST_CERT=true

Then just run:

planview analyze --query "SELECT * FROM Sales.SalesOrderHeader"
planview analyze ./queries/ --output-dir ./results/

CLI arguments override .env values when both are provided.

Using the credential store — for longer-term use, store credentials in your OS keychain:

# Store credentials (once per server)
planview credential add sql2022 --user sa
# You'll be prompted for the password — it's stored in your OS credential store

# Now connect without --login/--password
planview analyze --server sql2022 --database AdventureWorks \
    --query "SELECT * FROM Sales.SalesOrderHeader" \
    --trust-cert --output-dir ./results/

Batch processing a folder of .sql files:

planview analyze ./queries/ --server sql2022 --database StackOverflow2013 \
    --login sa --password YourPassword \
    --trust-cert --output-dir ./results/

Batch mode produces three files per query:

• query_name.sqlplan — the raw execution plan XML (openable in SSMS or the Performance Studio GUI)
• query_name.analysis.json — structured analysis with warnings, missing indexes, and operator tree
• query_name.analysis.txt — human-readable text report

Manage credentials

planview credential add my-server --user sa        # prompts for password
planview credential add my-server --user sa -p pwd  # non-interactive
planview credential list                            # show stored credentials
planview credential remove my-server                # delete credential

Credentials are stored in the OS credential store — Windows Credential Manager on Windows, Apple Keychain on macOS. Nothing is written to disk in plaintext.

Example Output

These examples were generated against StackOverflow2013 on SQL Server 2022. Source queries are in examples/queries/, plans and analysis in examples/output/.

Text output (--output text)

Plan: 04_comment_heavy_posts.sqlplan
SQL Server: 1.564 (build 16.0.4222.2)
Statements: 1

--- Statement 1: SELECT ---
  Query: SELECT p.Id, p.Title, p.Score, COUNT(c.Id) AS CommentCount
         FROM dbo.Posts AS p JOIN dbo.Comments AS c ON c.PostId = p.Id
         WHERE p.PostTypeId = 1 GROUP BY p.Id, p.Title, p.Score
         HAVING COUNT(c.Id) > 20 ORDER BY CommentCount DESC
  Estimated cost: 4069.8700
  DOP: 8
  Runtime: 4551ms elapsed, 15049ms CPU
  Memory grant: 8,022,664 KB granted, 2,514,944 KB used

  Warnings:
    [Critical] Large Memory Grant: Query granted 7835 MB of memory.

  Operator warnings:
    [Critical] Parallelism (Node 0): Estimated 1 rows, actual 2,889 (2889x underestimated).
    [Critical] Sort (Node 1): Estimated 1 rows, actual 2,889 (2889x underestimated).
    [Warning] Sort (Node 1): Thread 1 processed 100% of rows. Work is heavily skewed.
    [Warning] Filter (Node 2): Filter discards rows late in the plan.

  Missing indexes:
    StackOverflow2013.dbo.Posts (impact: 74%)
      CREATE NONCLUSTERED INDEX [IX_Posts_PostTypeId]
      ON dbo.Posts (PostTypeId) INCLUDE (Score, Title)
    StackOverflow2013.dbo.Comments (impact: 19%)
      CREATE NONCLUSTERED INDEX [IX_Comments_PostId]
      ON dbo.Comments (PostId)

=== Summary ===
  Warnings: 8 (4 critical)
  Missing indexes: 2
  Actual stats: yes
  Warning types: Filter Operator, Large Memory Grant, Parallel Skew,
                 Row Estimate Mismatch, Scan With Predicate

JSON output (default)

The default JSON output includes the full operator tree, making it suitable for CI pipelines, LLM consumption, or further processing. See examples/output/ for complete examples.

Batch processing

$ planview analyze ./examples/queries/ --server sql2022 \
    --database StackOverflow2013 --trust-cert --output-dir ./results/

Capturing actual plans from sql2022/StackOverflow2013

[1/5] 01_top_users_by_posts ... OK (1.8s)
[2/5] 02_recent_questions ... OK (0.8s)
[3/5] 03_unanswered_high_score ... OK (0.7s)
[4/5] 04_comment_heavy_posts ... OK (4.7s)
[5/5] 05_user_vote_summary ... OK (4.3s)

Processed 5 files: 5 succeeded, 0 failed
Output: ./results/

Desktop GUI

The Avalonia-based GUI renders execution plans visually with the same operator icons as SSMS. Open .sqlplan files via File > Open or drag-and-drop.

Features:

• Graphical plan tree with cost percentages and row counts
• Warning badge on root node showing total warning count
• Plan Insights panel — three-column view with runtime summary, missing indexes, and wait stats visualization
• Zoom and pan (mouse wheel + middle-click drag)
• Minimap for quick navigation of large plans
• Color-coded links between operators based on accuracy ratio divergence (estimates vs actuals)
• Click any operator to see full properties (30 sections)
• Statement grid with sortable columns (cost, rows, DOP, warnings)
• Tooltips on hover with key operator metrics
• Advice for Humans — one-click text analysis report you can read or share
• Advice for Robots — one-click JSON export designed for LLMs and automation
• Plan Comparison — compare two plans side-by-side (cost, runtime, I/O, memory, wait stats)
• Copy Repro Script — extracts parameters, SET options, and query text into a runnable sp_executesql script
• Get Actual Plan — connect to a server and re-execute the query to capture runtime stats
• Query Store Analysis — connect to a server and analyze top queries by CPU, duration, or reads
• Query History — view a history of executed queries with their plans along the timeline and metrics from query store
• MCP Server — built-in Model Context Protocol server for AI-assisted plan analysis (opt-in)
• Dark theme

dotnet run --project src/PlanViewer.App

SSMS Extension

A VSIX extension that adds "Open in Performance Studio" to the execution plan right-click context menu in SSMS 18-22.

How it works

1. Right-click on any execution plan in SSMS
2. Click "Open in Performance Studio"
3. The extension extracts the plan XML via reflection and saves it to a temp file
4. Performance Studio opens with the plan loaded

Installation

1. Download PlanViewer.Ssms.vsix and InstallSsmsExtension.exe from the v0.7.0 release (SSMS extension is not yet included in automated builds)
2. Place them in the same folder
3. Double-click InstallSsmsExtension.exe and approve the UAC prompt
4. The installer auto-detects SSMS 21 and/or SSMS 22 and installs into both
5. Restart SSMS to activate the extension

First run

On first use, if Performance Studio isn't found automatically, the extension will prompt you to locate PlanViewer.App.exe. The path is saved to the registry (HKCU\SOFTWARE\DarlingData\SQLPerformanceStudio\InstallPath) so you only need to do this once.

The extension searches for the app in this order:

1. Registry key (set automatically after first browse)
2. System PATH
3. Common install locations (%LOCALAPPDATA%\Programs\SQLPerformanceStudio\, Program Files, etc.)

MCP Server (LLM Integration)

The desktop GUI includes an embedded Model Context Protocol server that exposes loaded execution plans and Query Store data to LLM clients like Claude Code and Cursor.

Setup

1. Enable the MCP server in ~/.planview/settings.json:

{
  "mcp_enabled": true,
  "mcp_port": 5152
}

2. Register with Claude Code:

claude mcp add --transport http --scope user performance-studio http://localhost:5152/

3. Open a new Claude Code session and ask questions like:
   • "What plans are loaded in the application?"
   • "Analyze the execution plan and tell me what's wrong"
   • "Are there any missing index suggestions?"
   • "Compare these two plans — which is better?"
   • "Fetch the top 10 queries by CPU from Query Store"

Available Tools

13 tools for plan analysis and Query Store data:

Category	Tools
Discovery	list_plans, get_connections
Plan Analysis	analyze_plan, get_plan_summary, get_plan_warnings, get_missing_indexes, get_plan_parameters, get_expensive_operators, get_plan_xml, compare_plans, get_repro_script
Query Store	check_query_store, get_query_store_top

Plan analysis tools work on plans loaded in the app (via file open, paste, query execution, or Query Store fetch). Query Store tools use a built-in read-only DMV query — no arbitrary SQL can be executed.

The MCP server binds to localhost only and does not accept remote connections. Disabled by default.

Project Structure

PerformanceStudio/
├── src/
│   ├── PlanViewer.Core/       # Analysis engine (parser, 30 rules, layout)
│   ├── PlanViewer.App/        # Avalonia desktop GUI
│   ├── PlanViewer.Cli/        # CLI tool (planview command)
│   ├── PlanViewer.Ssms/       # SSMS extension (.vsix, .NET Framework 4.7.2)
│   └── PlanViewer.Ssms.Installer/ # SSMS extension installer (auto-detects SSMS 21/22)
├── tests/
│   └── PlanViewer.Core.Tests/ # 37 xUnit tests with real .sqlplan fixtures
├── examples/
│   ├── plans/                 # Sample .sqlplan files for testing
│   ├── queries/               # Sample .sql files
│   └── output/                # Generated .sqlplan, .analysis.json, .txt
└── PlanViewer.sln

CLI Reference

planview analyze

Usage: planview analyze [<file>] [options]

Arguments:
  <file>    .sqlplan file, .sql file, or directory of .sql files

Options:
  --stdin                    Read plan XML from stdin
  -o, --output <format>      json (default) or text
  --compact                  Compact JSON (no indentation)
  --warnings-only            Skip operator tree, only output warnings and indexes
  -s, --server <name>        SQL Server name (matches credential store key)
  -d, --database <name>      Database context for execution
  -q, --query <sql>          Inline SQL text to execute
  --output-dir <path>        Directory for output files
  --estimated                Estimated plan only (query is NOT executed)
  --auth <type>              windows, sql, or entra (default: auto-detect)
  --trust-cert               Trust server certificate
  --timeout <seconds>        Query timeout (default: 60)
  --login <name>             SQL Server login (bypasses credential store)
  --password <password>      SQL Server password (bypasses credential store)

planview credential

planview credential add <server> --user <user> [-p <password>]
planview credential list
planview credential remove <server>

Authentication

There are three ways to authenticate, in order of precedence:

1. --login / --password — passed directly on the command line (or via .env file). Simplest for dev/test.
2. Credential store — stored in Windows Credential Manager or Apple Keychain via planview credential add. Best for repeated use.
3. Windows Authentication — used automatically when no SQL credentials are found. Requires a valid Kerberos ticket.

Override the auto-detection with --auth windows, --auth sql, or --auth entra.

macOS note: Windows Authentication does not work on macOS (no Kerberos ticket by default). Use --login/--password, the credential store, or --auth entra instead.

Platform Support

Platform	GUI	CLI	Credential Store
Windows	Yes	Yes	Windows Credential Manager
macOS	Yes	Yes	Apple Keychain
Linux	Yes	Yes	Not yet (file analysis works)

macOS: SQL Server via Docker

macOS users need a SQL Server instance to use the live capture features. The easiest path is Docker:

docker run -e "ACCEPT_EULA=Y" -e "MSSQL_SA_PASSWORD=YourPassword123" \
    -p 1433:1433 --name sql_server \
    -d mcr.microsoft.com/mssql/server:2022-latest

# Store the credential
planview credential add localhost --user sa -p YourPassword123

# Test connectivity
planview analyze --server localhost --database master --trust-cert \
    --query "SELECT @@VERSION" -o text

Always use --trust-cert with local Docker instances.

Analysis Rules

The analyzer runs 30 rules against each plan, covering:

Category	Rules
Memory	Large grants, grant vs used ratio, spills to TempDB (including exchange spills)
Estimates	Row estimate mismatches (10x+), zero-row actuals, row goals
Indexes	Missing index suggestions, key lookups, RID lookups, scan with residual predicates
Parallelism	Serial plan reasons, thread skew, ineffective parallelism, DOP reporting
Joins	Nested loop high executions, many-to-many merge join worktables
Filters	Late filter operators with impact quantification, function-wrapped predicates
Functions	Scalar UDF detection (T-SQL and CLR), UDF timing
Parameters	Compiled vs runtime values, sniffing issue detection
Patterns	Leading wildcards, implicit conversions (with seek plan severity upgrade), OPTIMIZE FOR UNKNOWN, NOT IN with nullable columns, OR expansion, CASE in predicates
Compilation	High compile CPU, compile memory exceeded, early abort
Objects	Table variables, table-valued functions, CTE multiple references, eager index spools, lazy spools, row count spools
Operators	Operator self-time calculation with per-thread awareness for parallel plans

Rules can be disabled or have their severity overridden via a .planview.json config file. See the --config option.

Sponsors

Free code signing on Windows provided by SignPath.io, certificate by SignPath Foundation

License

MIT — see LICENSE.

Execution plan operator icons are from Microsoft's vscode-mssql extension (MIT). See THIRD_PARTY_NOTICES.md for details.