Cost-Based Oracle Fundamentals

APPENDIX AUpgrade Headaches

When you upgrade from one version of Oracle to another, or even from one patch release to the next, there are bound to be some areas of your code where things just go wrong. The optimizer is a prime target for this kind of issue. New features that improve 99% of all known queries may cripple your database because you fall into the remaining 1% of special cases.

This appendix is just a brief summary of features of the optimizer that may cause problems because implementation details have changed across versions 8i, 9i, and 10g. Every feature (and the possible problem it may introduce) is described in greater detail in the body of the book. The purpose of pulling all the changes into one appendix is to give you a quick ...