--- /dev/null
+I'm thinking about caching the backlinks between runs. --[[Joey]]
+
+* It would save some time (spent resolving every single link
+ on every page, every run). The cached backlinks could be
+ updated by only updating backlinks from changed pages.
+ (Saved time is less than 1/10th of a second for docwiki.)
+
+* It may allow attacking [[bugs/bestlink_change_update_issue]],
+ since that seems to need a copy of the old backlinks.
+ Actually, just the next change will probably solve that:
+
+* It should allow removing the `%oldlink_targets`, `%backlinkchanged`,
+ and `%linkchangers` calculation code. Instead, just generate
+ a record of which pages' backlinks have changed when updating
+ the backlinks, and then rebuild those pages.
+
+Proposal:
+
+* Store a page's backlinks in the index, same as everything else.
+
+* Do *something* to generate or store the `%brokenlinks` data.
+ This is currently generated when calculating backlinks, and
+ is only used by the brokenlinks plugin. It's not the right
+ "shape" to be stored in the index, but could be changed around
+ to fit.