Large reports

Large reports are reports with more than 50,000 rows of data or a run time over 5 minutes. They require a special approach to configuration for stable operation.

Google Sheets limits

Google Sheets has hard limits:

• 10,000,000 cells per spreadsheet (all sheets combined)
• 50,000 rows per sheet — the recommended maximum for stable operation
• 200 sheets per spreadsheet

LightLead automatically tracks how close you are to these limits and warns you while configuring a report.

Optimizing large reports

1. Reduce the number of rows

• Row limit — set a reasonable cap (Top 1000 instead of everything)
• Filters — exclude irrelevant data (for example, campaigns with zero spend)
• Aggregation — use a higher entity level (Campaign instead of Ad)
• Date range — narrow the period if you don't need the full history

2. Reduce the number of columns

• Select only the metrics you need
• Hide intermediate columns if they're not needed in the output
• Remove duplicate metrics (for example, CPC and Cost/Clicks)

3. Optimize the write mode

Mode	Speed	Recommendation for large reports
replace	Fast	Ideal
append + soft_refresh	Medium	OK for a daily tail
append + dumb	Fast	One-off exports; risk of duplicates
append_dedup	Medium	Slows down on large sheets

4. Split into multiple reports

Instead of a single 100,000-row report, create several:

• By campaign (a report per campaign group)
• By date (a report per month)
• By metric (basic metrics in one report, conversion metrics in another)

5. Use incremental loading

• For cumulative reports, use Append with yesterday
• Each run adds only 1 day of data
• Avoid last_30d with Append — every day adds 30 rows, so the sheet grows by 900 rows a month

Monitoring

• Run duration — if it grows from run to run, the sheet is approaching its limits
• Sheet size — check the row count on the destination sheet
• System warnings — LightLead will warn you as you approach Google Sheets limits

How to verify

• Open the destination sheet and check the row count (Ctrl+End)
• Check the duration of recent runs in the history — growing duration signals a problem
• Check for warnings on the report page

Related articles

• Row limit — capping the number of records
• Write modes (overview) — how the mode affects performance
• Filters — reducing data volume
• Metrics — selecting only the metrics you need
• Date range — narrowing the period