I will write and optimize sql queries for database performance
SQL and Power BI Expert
About this Gig
Is a slow database delaying your application or driving up cloud bills? Need expert SQL scripts?
As a Database Analyst and SQL Developer with 10+ years of corporate experience, I specialize in writing highly efficient database scripts and resolving critical performance bottlenecks. Whether you need a brand-new query designed from scratch or a complex legacy system optimized for live production, I deliver fast, clean, and production-grade code.
Databases Supported:
SQL Server (T-SQL) | PostgreSQL | MySQL | Oracle (PL/SQL) | MariaDB | SQLite | MS Access
️ Core Technical Services:
Performance Tuning: Query refactoring, indexing strategies, and execution plan analysis.
Script Engineering: Complex INNER/LEFT Joins, Subqueries, CTEs, and Window Functions.
Database Automation: Creating optimized Stored Procedures, Functions, Views, and Triggers.
Architecture Support: Normalization, schema debugging, and query performance optimization.
Please click the "Contact Me" button to share your database schema and project goals before placing an order!
Regards,
Nisar
Other Databases Services I Offer
FAQ
Will you help me understand the SQL queries that you have written?
Yes, absolutely! I provide fully documented SQL code with clear, inline comments explaining what each section of the script does. If you need a deeper explanation, I am happy to break down the logic of the joins, CTEs, or optimization steps via a detailed text summary or an interactive loom video so
What information or files do you need to start working on my SQL queries?
Please share a brief description of the data you want to retrieve, your specific database platform (e.g., SQL Server, PostgreSQL, MySQL), and your table schemas (table names, column names, and data types). Providing a small sample of mock data or an example of your expected output is highly helpful.
Do I need to share live production database access or login credentials with you?
No, your database security is a top priority. You do not need to share live credentials. You can provide the table structures (DDL scripts) and sample mock data via CSV or Excel files. If live database access is absolutely necessary, we can securely work through a staging environment or via screen-s
How do you optimize slow-running SQL queries?
Optimization involves carefully analyzing the database execution plan to look for costly operations like full table scans or nested loops. I then refactor inefficient subqueries into optimized Joins or Common Table Expressions (CTEs), implement smart indexing strategies, and tune the script to reduc
Can you build database objects like Stored Procedures, Triggers, and Functions?
Yes, absolutely! I write production-grade database scripts to handle automation and complex logic. This includes writing secure Stored Procedures, performance-tuned database Triggers, custom User-Defined Functions (UDFs), and Materialized Views across all major SQL environments.
Can you write highly complex queries that involve multiple tables?
Yes. With over a decade of data engineering experience, I routinely write complex scripts involving multiple table joins, deeply nested logic, window functions (like ROW_NUMBER and RANK), and aggregate grouping matrices. I ensure all my code is clean, highly optimized, and thoroughly documented.
8 reviews for this Gig
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Rating Breakdown
- Seller communication level
- Quality of delivery
- Value of delivery
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G goose12412

United States
Great knowledge of SQL and database query/design.
$50
Price
1 day
Duration
Helpful?J jmartip

Spain
Ongoing collaborationGreat attention to detail and very proactive. He went beyond expectations. I highly recommend it!
$50
Price
1 day
Duration
Helpful?V vib_28

United Kingdom
Ongoing collaborationtop work by the seller
$200-$400
Price
9 days
Duration
Helpful?V vib_28

United Kingdom
Ongoing collaborationVery good
$50-$100
Price
1 day
Duration
Helpful?M matthewwozniuk

Netherlands
very talented coder, he went above and beyond and even delivered early! super helpful thank you :)
$100-$200
Price
Helpful?
8 reviews for this Gig
| (8) | ||
| (0) | ||
| (0) | ||
| (0) | ||
| (0) |
Rating Breakdown
- Seller communication level
- Quality of delivery
- Value of delivery
Sort By
G goose12412

United States
Great knowledge of SQL and database query/design.
$50
Price
1 day
Duration
Helpful?J jmartip

Spain
Ongoing collaborationGreat attention to detail and very proactive. He went beyond expectations. I highly recommend it!
$50
Price
1 day
Duration
Helpful?V vib_28

United Kingdom
Ongoing collaborationtop work by the seller
$200-$400
Price
9 days
Duration
Helpful?V vib_28

United Kingdom
Ongoing collaborationVery good
$50-$100
Price
1 day
Duration
Helpful?M matthewwozniuk

Netherlands
very talented coder, he went above and beyond and even delivered early! super helpful thank you :)
$100-$200
Price
Helpful?
