How can I find out the min/max value form multiple tables?

[Ramya12]

I have three tables with each table having only one column that is ID column. I want to find out the maximun id out of the three tables. Pleas help me in this.

Thanks,
Ramya

[Rabbit]

Union the tables together and take the max of that.

[Luuk]

depending on the size of the three individual tables, it might be faster to find the min/max of each table and union that result to find min/max of all three tables.