Blocks in a million rows
- Input
- 1.000.000 linhas / 2.000 linhas por bloco
- Expected output
- 500 blocos
The progress bar advances with each block.
Carregando ferramenta… / Loading tool…
generate one million rows of test data
Yes, you can generate millions of rows without a server: the tool produces the data in blocks, in a separate browser process, and builds the file piece by piece. This text explains how that works, what uses memory and how to do the size math before you start.
The progress bar advances with each block.
An estimate, from the sample average.
Worth writing straight to disk in Chrome or Edge here.
Adjustable under Rows per INSERT.
There is no fixed row limit beyond a safety ceiling of 100 million per table, which only guards against typos. The real limit is your device's memory and disk: data is generated in blocks of 2,000 rows and the browser builds the file piece by piece. In Chromium browsers, from 100,000 rows the tool asks for a location to write straight to disk, without gathering the whole file in memory. The estimated file size appears below the preview, computed from the sample, and you can cancel a long run at any time.
It should not: the heavy work stays in the Web Worker and the page only receives progress messages. If the browser blocks workers because of a security policy on the page embedding the tool, it falls back to the main thread and yields between blocks, slower but without freezing.
CSV, with the database's native load utility (COPY in PostgreSQL, LOAD DATA in MySQL, .import in SQLite, bcp in SQL Server). INSERTs are useful for smaller volumes and for anyone who needs a single script with CREATE TABLE.
Split into smaller runs, each with its own seed and the id sequence starting where the last one ended, and join the files afterwards (cat, in the case of NDJSON and of CSV without a header in later runs). Avoid the unique flag on small-bank text types and the JSON array for tens of millions of rows.
Fictitious data for testing. Documents only have the correct format and check digits, belong to no one and must not be used for fraud or to bypass verification. Cards and IBANs move no money.