Identity column maximum value in SQLite DBs
I have a purely academic question about SQLite databases.
I am using SQLite.net to use a database in my WinForm project, and as I was setting up a new table, I got to thinking about the maximum values of an ID column.
I use the IDENTITY for my [ID] column, which according to SQLite.net DataType Mappings, is equivalent to DbType.Int64. I normally start my ID columns at zero (with that row as a test record) and have the database auto-increment.
The maximum value (Int64.MaxValue) is 9,223,372,036,854,775,807. For my purposes, I'll never even scratch the surface on reaching that maximum, but what happens in a database that does? While trying to read up on this, I found that DB2 apparently "wraps" the value around to the negative value (-9,223,372,036,854,775,807) and increments from there, until the database can't insert rows because the ID column has to be unique.
Is this what happens in SQLite and/or other database engines?
Answer
I doubt anybody knows for sure, because if a million rows per second were being inserted, it would take about 292,471 years to reach the wrap-around-risk point -- and databases have been around for a tiny fraction of that time (actually, so has Homo Sapiens;-).