7868590c61
cost_nonsequential_access() is really totally inappropriate for its only remaining use, namely estimating I/O costs in cost_sort(). The routine was designed on the assumption that disk caching might eliminate the need for some re-reads on a random basis, but there's nothing very random in that sense about sort's access pattern --- it'll always be picking up the oldest outputs. If we had a good fix on the effective cache size we might consider charging zero for I/O unless the sort temp file size exceeds it, but that's probably putting much too much faith in the parameter. Instead just drop the logic in favor of a fixed compromise between seq_page_cost and random_page_cost per page of sort I/O. |
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| .. | ||
| Makefile | ||
| allpaths.c | ||
| clausesel.c | ||
| costsize.c | ||
| indxpath.c | ||
| joinpath.c | ||
| joinrels.c | ||
| orindxpath.c | ||
| pathkeys.c | ||
| tidpath.c | ||