You’re looking at a wide table with 100-200 columns.
Years ago, it started as a “normal” table with maybe 10-20, but over the years, people kept gradually adding one column after another. Now, this behemoth is causing you problems because:
The table’s size on disk is huge Queries are slow, especially when they do table scans People are still asking for more columns, and you feel guilty saying yes
You’ve started to think about vertical partitioning: splitting the table up into one table with the commonly used columns, and another table with the rarely used columns. You figure