estimate_path_cost_size() failed to re-use cached costs when the cached
startup/total cost was 0, so it calculated the costs redundantly.
This is an oversight in commit
aa09cd242f; but apply the patch to HEAD
only because there are no reports of actual trouble from that.
Author: Etsuro Fujita
Discussion: https://postgr.es/m/
5C4AF3F3.
4060409%40lab.ntt.co.jp
index 9244fe7571f60b1f30f5e86ed528f2919b593987..1a88919cfcad8068355d54294eb609fa4aa5c54e 100644 (file)
* bare scan each time. Instead, use the costs if we have cached them
* already.
*/
- if (fpinfo->rel_startup_cost > 0 && fpinfo->rel_total_cost > 0)
+ if (fpinfo->rel_startup_cost >= 0 && fpinfo->rel_total_cost >= 0)
{
startup_cost = fpinfo->rel_startup_cost;
run_cost = fpinfo->rel_total_cost - fpinfo->rel_startup_cost;