AI Query Optimizer
Optimize slow SQL queries for faster database performance
NVIDIA: Nemotron 3 Super
Balanced Nemotron for demanding everyday work
NEW
FREE
Your prompt will appear here…
Your beautifully formatted article will appear here once you generate.
No history yet
Your generations will appear here. Sign in to save them permanently.
Why does a query that ran in forty milliseconds last quarter now take nine seconds? Nothing in the SQL changed. The table grew, an index stopped covering the filter, and a join that was cheap on ten thousand rows became expensive on two million. Slow queries are almost never a mystery once you look, but looking takes knowledge that is easy to be rusty on.
Short answer: AI Query Optimizer reads a slow SQL statement and returns a rewritten version for your database engine, along with the indexes and structural changes that would make it faster.
What is AI Query Optimizer?
It is a free tool for the moment a query is correct but too slow. You paste the statement, name your engine, and it comes back with a rewrite and a reasoned explanation of what was costing time. Filters that could not use an index, a subquery that ran once per row, a DISTINCT hiding a duplicate join: those are the patterns it is looking for.
It works on the SQL you give it. There is no connection to your database, no execution plan being read, no statistics being sampled. That sounds like a limitation and it is, but it also means you can paste a query from a log file on a laptop with no access to anything and still get useful direction.
Rewrites, not just advice
You get the improved statement itself, ready to run, rather than a list of general principles.
Engine aware
What is fast on PostgreSQL is not always fast on MySQL, so the dialect setting changes the advice.
Index suggestions
Switching Output Type to Index Plan turns the same query into the indexes that would support it.
Reasoning you can check
The Explained format gives you the argument behind each change, which is what makes it reviewable.
Attempts kept side by side
Session history holds every version you generated, so comparing two rewrites costs nothing.
Why Use AI Query Optimizer?
Because query tuning is a knowledge problem more than an effort problem. Once someone points out that your date filter is wrapped in a function and therefore cannot use the index, the fix takes thirty seconds. Finding that out on your own can take an hour of reading plans you look at twice a year.
The other reason is triage. When four queries are slow and you have an afternoon, you need to know which one has a cheap fix. AI Query Optimizer gives you a fast read on each, and the ones that come back with "this needs a schema change" can be separated from the ones that need a comma moved.
What works well
- Spots the well known anti patterns quickly and explains why they cost time.
- Returns a runnable rewrite rather than generic tuning advice.
- Doubles as a teaching tool, since the reasoning is written out.
- Free and open, so checking six queries is as easy as checking one.
What to watch for
- It cannot see your execution plan, your statistics or your row counts.
- A rewrite can change results if the original had subtle duplicate handling.
- Suggested indexes cost write time, so accepting all of them is a mistake.
- Real proof still comes from timing the query on your own data.
Who Should Use It?
- Application developers who own their SQL but do not tune databases full time.
- Analysts whose dashboards have quietly become the slowest thing in the company.
- Small teams with no database administrator to escalate to.
- Engineers preparing for a review where they need to justify a rewrite in words.
- Anyone learning why one join order beats another and wanting worked examples.
How Does AI Query Optimizer Work?
The page follows the same shape as the other tools here. A prompt box takes your statement, a model selector chooses the engine that reasons about it, an accordion holds the database specific settings, and the result appears in a card underneath with its own copy button and a live word count.
What you feed it matters more than which options you tick. A bare SELECT gives the tool nothing but syntax to work with. The same SELECT with the CREATE TABLE statements, the existing indexes and a note that the orders table holds a few million rows gives it enough context to reason about selectivity, and the answer changes accordingly.
Tip Paste the EXPLAIN output alongside the query. Even without a live connection, the plan text tells the tool which step is expensive, and the advice narrows immediately.
Step-by-Step Guide
- Open AI Query Optimizer. Nothing to install and no account to create.
- Paste the slow query into the prompt box, then add your table definitions, current indexes and a rough row count for the big tables.
- Pick a model. The selector lists MSB AI, OpenAI ChatGPT, DeepSeek, xAI Grok AI and more, and a second opinion from a different engine is often worth the extra ten seconds.
- In advanced options, set Database to your engine and leave Output Type on Query for a rewrite.
- Set Complexity to Optimized. This is the one tool where that setting is the whole point.
- Turn Add Comments on so each change carries its justification into your pull request.
- Generate, read the rewrite, then run both versions on a copy of your data and time them.
The export row under the result offers DOC, TXT and HTML, plus copy, listen, reuse and open in full view. Reuse is genuinely handy here: send the rewrite back into the prompt box and ask for a second pass with the indexes included.
Before you accept any rewrite, work down this short list.
- ✅ Row counts match between the original query and the rewrite.
- ✅ Both versions timed on the same data, not on your laptop against a seed file.
- ✅ Every suggested index checked against the write load on that table.
- ✅ Any changed join type understood, since INNER and LEFT are not interchangeable.
- ✅ Ordering still guaranteed if the application depends on it.
- ✅ The reasoning read, not just the SQL copied.
Caution A rewrite that removes a DISTINCT or changes a LEFT JOIN to an INNER JOIN can change your result set, not just its speed. Compare row counts between the old and new query before you ship anything.
Best Use Cases
| Symptom | What to paste | Settings worth using |
|---|---|---|
| Report that used to be instant | Query, table sizes, existing indexes | Complexity Optimized, Format Code + Comments |
| Query fine locally, slow in production | Query plus the production row counts | Include Indexes on, Detail Level high |
| Nightly job overrunning its window | The whole statement including the update or delete | Add Comments on, Complexity Advanced |
| You suspect a missing index | Query and current index list | Output Type Index Plan |
Application code often shares the blame. If the query is slow because it runs once per row in a loop, the fix belongs in the code rather than the SQL, and AI Code Optimizer is the better place to take that problem.
Advanced Options Guide
Ten controls sit in the accordion. Three of them change the answer materially for optimisation work, and the rest shape presentation.
| Option | What it controls | When to change it | Suggested starting point |
|---|---|---|---|
| Database | Dialect across Auto, MySQL, PostgreSQL, SQLite, SQL Server, Oracle, MongoDB and MariaDB. | Always. Optimisation advice is engine specific by nature. | Your production engine, never Auto. |
| Output Type | Query, Schema, Migration, ER Diagram, Stored Procedure, Index Plan or Data Model. | Query for a rewrite, Index Plan when you want the supporting indexes instead. | Query, then rerun as Index Plan. |
| Complexity | Simple, Standard, Advanced or Optimized. | This is the tuning dial. Optimized pushes toward index friendly rewrites. | Optimized. |
| Format | SQL, Code + Comments, Explained or Table. | Explained when you need to defend the change to a reviewer. | Code + Comments. |
| Add Comments | Inline reasoning above each altered clause. | Any rewrite going into review. | On. |
| Include Indexes | Adds the CREATE INDEX statements that support the rewrite. | Whenever the bottleneck looks like a missing index. | On. |
| Add Constraints | Key and null rules on any tables the answer defines. | Rarely relevant when optimising an existing query. | Off. |
| Include Sample Data | Example rows to test the rewrite against. | When you want something to run immediately on a scratch database. | Off. |
| Detail Level | Slider from 1 to 100 for how much explanation surrounds the SQL. | High when you are learning, low when you just want the statement. | High, since the reasoning is the value here. |
| Custom Instructions | Free text up to 1000 characters for context the dropdowns cannot carry. | Row counts, hardware limits, indexes you cannot add. | Something concrete such as "orders has 4 million rows, cannot add indexes to it". |
Comparison Table
| Method | What it sees | Effort | Best for |
|---|---|---|---|
| Reading the execution plan yourself | Real statistics and real costs | High, and rusty knowledge slows it | The final proof before you ship |
| Adding indexes and hoping | Nothing | Low, with a write penalty later | Almost nothing |
| Asking a colleague | Their experience of your system | Their time, not yours | Queries tied to business rules |
| AI Query Optimizer | The SQL and whatever context you paste | Low, seconds per query | First pass triage and learning why |
Pro tip Run the rewrite and the original in the same session and compare both the timing and the row count. A faster query that returns a different number of rows has not been optimised, it has been broken.
AIToolsay is built around the idea that you should land on a page that already understands the job. Here that means a prompt box expecting SQL, an options panel with a dialect setting and a complexity dial that actually matters, and a model selector so a second engine can take a look at the same statement. There is no account to create and nothing to pay, so you can put every slow query from this week through it in one sitting. Session history keeps each rewrite listed under the result while you work, which makes comparing two approaches straightforward. The same structure runs across the rest of the tools on AIToolsay, so the schema, index and code steps around this one are each a single page away.
Frequently Asked Questions
Does AI Query Optimizer connect to my database?
No. It reads only what you paste, which means nothing leaves your control beyond the text of the query and any context you choose to include.
Is it free to use?
Yes. There is no account, no meter and no limit on how many queries you check.
How much context should I include?
Table definitions, current indexes and rough row counts change the answer more than any option. If you have EXPLAIN output, paste that too.
Will the rewrite definitely be faster?
Not automatically. It will remove known anti patterns, which is usually enough, but real speed depends on your data distribution. Time both versions before you ship.
Can it suggest indexes instead of a rewrite?
Yes. Keep the same query and set Output Type to Index Plan, and you get the supporting indexes rather than a new statement.
What if I cannot change the schema?
Say so in Custom Instructions. Telling it that you cannot add indexes or alter a table pushes the answer toward rewrites that work within those limits.
Does it handle stored procedures and views?
Yes, and it helps to paste the definitions of any views involved. A query over a view is often slow because of what the view does, not because of the outer statement.
Pick the slowest query you know about, paste it with its table definitions, and read the explanation before the rewrite. Understanding why it was slow is worth more than the new statement. If you want to compare notes on tuning, the Telegram community is active, and the newsletter or push notifications will flag new database tools as they land.
Let AI Speak.
Sabir
Founder of AIToolsay and a passionate AI enthusiast dedicated to building practical, user-friendly AI tools that simplify everyday tasks.
Can't find the tool you need?
Tell us what you need and we will build it. New tools ship every week.
Request a Tool