Hi, some performance issue to ask.

consider a Master-Child situation, where tblA and tblB is both Master and having the same Child table structure. Some people recommend using the same table as Child for both tblA and tblB as this save resources. Any comments on this? Does it really good or bad? Would it involves higher page read and write? What cost is there actually in having extra tables in SQL Server?

I'd avoid doing this. Not for performance reasons, but because it makes for a poor database design. Each table/database entity should be created for one purpose. To blend together two tables blurs that purpose. I suspect that you might also have problems defining two foreign key relationships on the child column.

I don't think you'd gain much performance. If anything you'd probably lose performance, as the tables would be longer, resulting is more rows to scan for joins, where conditions and the like.

regards
David Cameron