We have recently gone through a change to migrate over our tables from using int to bigint. Our roll out plan is to run with temporary tables on bigint before migrating permanent tables.
This is causing us problems with queries with more than 7 tables where sybase goes for table scans. Simon Ogden pointed me in the direction of setting alternative_greedy_search and this seems to work for 2 out of 3 problems that we have seen so far.
I would just like to read a little bit more about this optimisation. Is there any document about it, I couldn't find any searching for it.