row-chaining problem

[dba_admin]

I have a column with date data type. Most of the rows in the table have null value in this date column. If, in the future, the date column is likely to be updated so that it contains data, could this cause any row-chaining problem?

[slimdave]

It's more likely that it would cause row migration.

If individual rows grow so that they can no longer be stored in that block, then they will be migrated to another block with space for them.

If they are so large that they cannot be contained in a single block, then they would be split over multiple blocks -- this is row chaining.

Either of these is a problem, but migration is more easily fixed.