The greatest undocumented environmental variable ever

OK, maybe it's not that great, but it's proved damn useful to me. IFX_DIRTY_WAIT Basically, you set it to a timeout value, and with it set, you can issue, say, an ALTER TABLE statement without immediately getting an ISAM -106 (non-exclusive access). Instead, it keeps trying, waiting for the timeout, before giving the error. So if you need to alter a table or build an index where you have dirty readers out there, this is quite handy. Detailed info here: http://www-1.ibm.com/support/docview.wss?uid=swg21174239 If it's documented anywhere else, I haven't found it. I only learned of it from the IBM Premium Support newsletter for November of 2006. Apparently, the feature was added in 7.31.xD5, 9.30.xC3, 9.40.xC1, and 10.00.xC1, back before February of 2005, but I just now learned of it. I thought I might not be the only one in the dark about this, and that others might find it as useful as I have.