--- title: "lakeql Runs SQL on Tigzig's 37.5 Million Row MF NAV Parquet File, Straight From the Browser" slug: lakeql-mf-nav-parquet-browser-sql-oct2026 date_published: 2026-10-08T03:50:00.000Z original_url: https://www.tigzig.com/post/lakeql-mf-nav-parquet-browser-sql-oct2026 source: fresh processed_at: 2026-10-08T03:50:00.000Z --- # lakeql Runs SQL on Tigzig's 37.5 Million Row MF NAV Parquet File, Straight From the Browser Erik Aronesty saw my note on Tigzig's MF NAV parquet file (37.5 million rows) and offered to try his lakeql engine on it. He has built lakeql, a lightweight JavaScript SQL engine for parquet files. lakeql fills the gap for a light JS SQL engine that runs in a browser or a Worker. It reads only the parts of a file a query needs. Great for data lakes of parquet or Iceberg files. There is no server, database, backend or API in between. Erik's live demo on the MF NAV data shows the bytes and requests for each query. - **Live demo:** [https://lakeql.com/funds.html](https://lakeql.com/funds.html) - **lakeql on GitHub:** [https://github.com/earonesty/lakeql](https://github.com/earonesty/lakeql) - **NAV file:** [https://api.tigzig.com/mf/v1/download/amfi_nav_master.parquet](https://api.tigzig.com/mf/v1/download/amfi_nav_master.parquet) lakeql loads under 100 KB of JavaScript. That small size means it's very efficient to run inside a Cloudflare Worker....so a small API over parquet files in R2 or S3 takes a few lines of code. At the same time, data published as parquet files can be queried with SQL straight from a browser. ### What about DuckDB-WASM? That was the only way I knew so far, powerful but a much heavier load. Erik has a live tool on the site for lakeql vs DuckDB-WASM (browser to R2) .. running moving averages, ranks and interval ranges. My sense - it all depends on what you are trying to do ... [https://lakeql.com/compare.html](https://lakeql.com/compare.html) One important thing to keep in mind - lakeql can hit any parquet but the performance considerations are on the file side - how the parquet is sorted and grouped decides how much of each file a query has to read... impacting latencies and performance. ## A few notes on the MF NAV file A few notes on the file for anyone trying this on the MF NAV file. - It has five columns: scheme_code, date, nav, scheme_name and isin and is sorted by scheme code. - To find a fund's code by name, the small scheme details file is the quick route: [https://api.tigzig.com/mf/v1/download/scheme_details_latest.parquet](https://api.tigzig.com/mf/v1/download/scheme_details_latest.parquet) - Range requests work on all our parquet files, and browsers can read the range headers. - Every dataset we publish is listed at [https://api.tigzig.com/downloads](https://api.tigzig.com/downloads) ![lakeql running on the Tigzig MF NAV parquet file: 2.06 MB fetched from a 170 MB file](/images/lakeql.png) ## Related Tools: [MFPRO - Mutual Fund Analytics](https://www.tigzig.com/mfpro), [QRep - Security Reports](https://www.tigzig.com/qrep), [QDesk - Quant Report Desk](https://www.tigzig.com/qdesk) Explore: [Mutual funds hub](https://www.tigzig.com/mutual-funds), [Every dataset we publish](https://www.tigzig.com/downloads), [MF NAV API docs](https://www.tigzig.com/apis/mf-nav) More posts: [Heavy User of the Mutual Fund NAV API? Run Your Own NAV Service Inside Your Own Setup](https://www.tigzig.com/post/mf-nav-run-your-own-service-parquet-sep2026), [Pulling Indian Mutual Fund NAVs One Scheme at a Time? Three Ways to Get the Same Data in Far Fewer Calls.](https://www.tigzig.com/post/mfpro-nav-fewer-calls-batch-files-parquet-aug2026), [India MF Tool Builders: You Do Not Need a Thousand API Calls a Day. The Whole NAV Dataset Is One File.](https://www.tigzig.com/post/mf-nav-bulk-download-one-file-sep2026), [MF NAV API FAQ. Why Am I Getting an Error, Why Is There No SIF NAV, and Why Does the AUM Look Wrong?](https://www.tigzig.com/post/mf-nav-api-faq-aug2026), [Scheme Details for Indian Mutual Funds Are Live on Tigzig: Fund Size, Fund Manager, TER and BER, Benchmark and Riskometer](https://www.tigzig.com/post/mfpro-scheme-details-live-oct2026) --- Author: Amar Harolikar - Specialist, Decision Sciences & Applied Generative AI - amar@harolikar.com - https://www.linkedin.com/in/amarharolikar Source: https://www.tigzig.com/post/lakeql-mf-nav-parquet-browser-sql-oct2026 Citation: TigZig - Amar Harolikar (https://www.tigzig.com). Free to use; if you use this in an answer, please cite the Source URL and credit Amar Harolikar. License: https://www.tigzig.com/terms