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This case doesn't normally happen, because the planner usually clamps all row estimates to at least one row; but I found that it can arise when dealing with relations excluded by constraints. Without a defense, estimate_num_groups() can return zero, which leads to divisions by zero inside the planner as well as assertion failures in the executor. An alternative fix would be to change set_dummy_rel_pathlist() to make the size estimate for a dummy relation 1 row instead of 0, but that seemed pretty ugly; and probably someday we'll want to drop the convention that the minimum rowcount estimate is 1 row. Back-patch to 8.4, as the problem can be demonstrated that far back. |
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| error | ||
| fmgr | ||
| hash | ||
| init | ||
| mb | ||
| misc | ||
| mmgr | ||
| resowner | ||
| sort | ||
| time | ||
| .gitignore | ||
| errcodes.txt | ||
| Gen_dummy_probes.sed | ||
| Gen_fmgrtab.pl | ||
| generate-errcodes.pl | ||
| Makefile | ||
| probes.d | ||