SQL Lab query limit too large to handle default settings

[villebro]

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• I have checked the superset logs for python stacktraces and included it here as text if any
• I have reproduced the issue with at least the latest released version of superset
• I have checked the issue tracker for the same issue and I haven't found one similar

Superset version

master

Expected results

When submitting a query via SQL Lab, the query should only display a sensible amount of rows, e.g. the default value of DISPLAY_SQL_MAX_ROW (set to 1,000 in config.py).

Actual results

The query is limited to SQL_MAX_ROW (set to 1,000,000 in config.py), which causes unnecessary strain on the datasource and crashes the browser on large tables.

Steps to reproduce

1. Open SQL Lab
2. Write query against big table
3. Wait for browser to crash.