diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtsort.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtsort.c | 42 |
1 files changed, 22 insertions, 20 deletions
diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c index ba230bbcd2e..15f10a29d3d 100644 --- a/src/backend/access/nbtree/nbtsort.c +++ b/src/backend/access/nbtree/nbtsort.c @@ -269,7 +269,8 @@ static Page _bt_blnewpage(uint32 level); static BTPageState *_bt_pagestate(BTWriteState *wstate, uint32 level); static void _bt_slideleft(Page page); static void _bt_sortaddtup(Page page, Size itemsize, - IndexTuple itup, OffsetNumber itup_off); + IndexTuple itup, OffsetNumber itup_off, + bool newfirstdataitem); static void _bt_buildadd(BTWriteState *wstate, BTPageState *state, IndexTuple itup, Size truncextra); static void _bt_sort_dedup_finish_pending(BTWriteState *wstate, @@ -750,26 +751,24 @@ _bt_slideleft(Page page) /* * Add an item to a page being built. * - * The main difference between this routine and a bare PageAddItem call - * is that this code knows that the leftmost data item on a non-leaf btree - * page has a key that must be treated as minus infinity. Therefore, it - * truncates away all attributes. + * This is very similar to nbtinsert.c's _bt_pgaddtup(), but this variant + * raises an error directly. * - * This is almost like nbtinsert.c's _bt_pgaddtup(), but we can't use - * that because it assumes that P_RIGHTMOST() will return the correct - * answer for the page. Here, we don't know yet if the page will be - * rightmost. Offset P_FIRSTKEY is always the first data key. + * Note that our nbtsort.c caller does not know yet if the page will be + * rightmost. Offset P_FIRSTKEY is always assumed to be the first data key by + * caller. Page that turns out to be the rightmost on its level is fixed by + * calling _bt_slideleft(). */ static void _bt_sortaddtup(Page page, Size itemsize, IndexTuple itup, - OffsetNumber itup_off) + OffsetNumber itup_off, + bool newfirstdataitem) { - BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page); IndexTupleData trunctuple; - if (!P_ISLEAF(opaque) && itup_off == P_FIRSTKEY) + if (newfirstdataitem) { trunctuple = *itup; trunctuple.t_info = sizeof(IndexTupleData); @@ -867,12 +866,13 @@ _bt_buildadd(BTWriteState *wstate, BTPageState *state, IndexTuple itup, * Every newly built index will treat heap TID as part of the keyspace, * which imposes the requirement that new high keys must occasionally have * a heap TID appended within _bt_truncate(). That may leave a new pivot - * tuple one or two MAXALIGN() quantums larger than the original first - * right tuple it's derived from. v4 deals with the problem by decreasing - * the limit on the size of tuples inserted on the leaf level by the same - * small amount. Enforce the new v4+ limit on the leaf level, and the old - * limit on internal levels, since pivot tuples may need to make use of - * the reserved space. This should never fail on internal pages. + * tuple one or two MAXALIGN() quantums larger than the original + * firstright tuple it's derived from. v4 deals with the problem by + * decreasing the limit on the size of tuples inserted on the leaf level + * by the same small amount. Enforce the new v4+ limit on the leaf level, + * and the old limit on internal levels, since pivot tuples may need to + * make use of the reserved space. This should never fail on internal + * pages. */ if (unlikely(itupsz > BTMaxItemSize(npage))) _bt_check_third_page(wstate->index, wstate->heap, isleaf, npage, @@ -925,7 +925,8 @@ _bt_buildadd(BTWriteState *wstate, BTPageState *state, IndexTuple itup, Assert(last_off > P_FIRSTKEY); ii = PageGetItemId(opage, last_off); oitup = (IndexTuple) PageGetItem(opage, ii); - _bt_sortaddtup(npage, ItemIdGetLength(ii), oitup, P_FIRSTKEY); + _bt_sortaddtup(npage, ItemIdGetLength(ii), oitup, P_FIRSTKEY, + !isleaf); /* * Move 'last' into the high key position on opage. _bt_blnewpage() @@ -1054,7 +1055,8 @@ _bt_buildadd(BTWriteState *wstate, BTPageState *state, IndexTuple itup, * Add the new item into the current page. */ last_off = OffsetNumberNext(last_off); - _bt_sortaddtup(npage, itupsz, itup, last_off); + _bt_sortaddtup(npage, itupsz, itup, last_off, + !isleaf && last_off == P_FIRSTKEY); state->btps_page = npage; state->btps_blkno = nblkno; |