Hey everyone! I’m new here and could use some help with a database issue.
I added a boolean column to a big table to track item stock status. At first, it was null, so I updated it to false (in stock) for all rows. This worked fine on smaller databases.
But when I tried it on a huge table with about 2 billion rows, the database size jumped from 700GB to 800GB! I thought boolean columns were supposed to be tiny. What’s going on?
I’m not a database pro, so I’m kinda lost. Can anyone explain why this happened? I need to understand before I make changes to other databases.
Here’s a simplified version of what I did:
ALTER TABLE items ADD is_out_of_stock BIT;
UPDATE items SET is_out_of_stock = 0;
yo sophia, that’s a wild database jump! adding a tiny boolean shouldn’t blow up like that. my guess? the update mightve caused some table bloat or fragmentation. tried running VACUUM or reindexing? that could help shrink things back down. also, updating in smaller chunks might prevent this kinda explosion next time. good luck!
The unexpected size increase you’re seeing is likely due to how database engines handle data storage and updates. When a new column is added and updated across all rows, the database may rewrite the entire table. For a large table with 2 billion rows, this operation essentially creates a new version of each row, leading to increased storage usage. This internal rewriting and potential fragmentation can significantly inflate the database size.
To reduce this impact, consider updating rows in smaller batches or employing a partitioned table strategy. Post-update maintenance like vacuuming or rebuilding indexes might also help optimize storage.