Schema suggestions — See what a change would do first

Every suggestion is measured against your actual records before you decide, and says so plainly. The most useful thing it will tell you is how little most changes touch: changing a field's type rewrites nothing. Every value is stored as text, so retyping a column changes how it is read and not one byte of any record — and you can change it back. Where a change does touch stored data — removing an unused column, making a link an ownership one so children delete with their parent, extracting a table — the card says so in stronger terms. What this is based on opens the counts and sample values behind the suggestion, and where there is a row-by-row difference to look at, you can open that list too.