hi, all I am so sorry for asking some questions like this! Recently, for understanding postgresql's optimizer, I read and debug the source code. these two days, I read these macros in sysattr.h:
... #define ObjectIdAttributeNumber (-2) ... and the relative codes, but I still did not know why authors designed them like that, especially the value '-2' ? what should I do if I want to see the thoughts behind them? thanks in advance!
