On Thu, Jan 8, 2026 at 6:27 AM Heikki Linnakangas <[email protected]> wrote: > I noticed a trivial misspelling in the comment in > _bt_tuple_before_array_skeys, and when I started to look at the > surrounding comments, I noticed a few other things that could be > improved. Patch attached, but let me go through the changes one by one:
I'm fine with all these changes. > Some other functions take a "bool *continuescan" parameter, but this > function sets it in 'pstate'. FWIW this is an obsolete comment -- it used to have a continuescan parameter. > > @@ -1197,9 +1197,9 @@ _bt_checkkeys(IndexScanDesc scan, BTReadPageState > > *pstate, bool arrayKeys, > > > > /* > > * Only one _bt_check_compare call is required in the common case > > where > > - * there are no equality strategy array scan keys. Otherwise we > > can only > > - * accept _bt_check_compare's answer unreservedly when it didn't set > > - * pstate.continuescan=false. > > + * there are no equality strategy array scan keys. With array > > keys, we > > + * can only accept _bt_check_compare's answer unreservedly when it > > set > > + * pstate.continuescan=true. > > */ > > if (!arrayKeys || pstate->continuescan) > > return res; > > Double negative: "didn't set to false" means "did set to true" in this > context. And the sentence was a little difficult to parse in other ways > too: it takes some effort to decipher that "otherwise" means that there > are array keys, and "only accept unreservedly" sound like more negation. > (I didn't change the "only accept unreservedly" part) > > Are there other kind of array keys than "equality strategy array keys"? Yes. There are inequality array keys. Preprocessing will replace the scan key's sk_argument with the array's extremal key, so there isn't an array left behind after preprocessing. But there is still a SK_SEARCHARRAY marking. Maybe we should have preprocessing unset SK_SEARCHARRAY for such an inequality key, so that there really wouldn't be such a thing as an array inequality. That would allow us to stop testing each SK_SEARCHARRAY key's strategy in code like _bt_advance_array_keys. -- Peter Geoghegan
