77 *
88 *
99 * IDENTIFICATION
10- * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.13 1997/05/30 18 :35:31 vadim Exp $
10+ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.14 1997/05/31 06 :35:56 vadim Exp $
1111 *
1212 *-------------------------------------------------------------------------
1313 */
@@ -287,31 +287,22 @@ _bt_insertonpg(Relation rel,
287287
288288/*
289289 * If we have to split leaf page in the chain of duplicates
290- * then we try tomove righter to avoid splitting .
290+ * then we try tolook at our right sibling first .
291291 */
292292if ( (lpageop -> btpo_flags & BTP_CHAIN )&&
293293(lpageop -> btpo_flags & BTP_LEAF ) )
294294{
295295bool use_left = true;
296+ bool keys_equal = false;
296297
297- for ( ; ; )
298- {
299- bool keys_equal = false;
300-
301- rbuf = _bt_getbuf (rel ,lpageop -> btpo_next ,BT_WRITE );
302- rpage = BufferGetPage (rbuf );
303- rpageop = (BTPageOpaque )PageGetSpecialPointer (rpage );
304- if (P_RIGHTMOST (rpageop ) )
305- {
306- Assert ( !(rpageop -> btpo_flags & BTP_CHAIN ) );
307- use_left = false;
308- break ;
309- }
310- /*
298+ rbuf = _bt_getbuf (rel ,lpageop -> btpo_next ,BT_WRITE );
299+ rpage = BufferGetPage (rbuf );
300+ rpageop = (BTPageOpaque )PageGetSpecialPointer (rpage );
301+ if ( !P_RIGHTMOST (rpageop ) )/* non-rightmost page */
302+ {/*
311303 * If we have the same hikey here then it's
312- * yet another page in chain and we may move
313- * even righter.
314- */
304+ * yet another page in chain.
305+ */
315306if (_bt_skeycmp (rel ,keysz ,scankey ,rpage ,
316307PageGetItemId (rpage ,P_HIKEY ),
317308BTEqualStrategyNumber ) )
@@ -321,12 +312,12 @@ _bt_insertonpg(Relation rel,
321312keys_equal = true;
322313 }
323314else if (_bt_skeycmp (rel ,keysz ,scankey ,rpage ,
324- PageGetItemId (rpage ,P_HIKEY ),
325- BTGreaterStrategyNumber ) )
326- elog (FATAL ,"btree: hikey is out of order" );
315+ PageGetItemId (rpage ,P_HIKEY ),
316+ BTGreaterStrategyNumber ) )
317+ elog (FATAL ,"btree: hikey is out of order" );
327318/*
328319 * If hikey > scankey and BTP_CHAIN is ON
329-
320+ * then it's first page of the chain of higher keys:
330321 * our left sibling hikey was lying! We can't add new
331322 * item here, but we can turn BTP_CHAIN off on our
332323 * left page and overwrite its hikey.
@@ -336,26 +327,19 @@ _bt_insertonpg(Relation rel,
336327BTItem tmp ;
337328
338329lpageop -> btpo_flags &= ~BTP_CHAIN ;
339- tmp = (BTItem )PageGetItem (rpage ,
340- PageGetItemId (rpage ,P_HIKEY ));
330+ tmp = (BTItem )PageGetItem (rpage ,PageGetItemId (rpage ,P_HIKEY ));
341331hiRightItem = _bt_formitem (& (tmp -> bti_itup ));
342- break ;
343332 }
344- /*
345- * if there is room here or hikey > scankey (so it's our
346- * last page in the chain and we can't move righter)
347- * we have to use this page .
348- */
349- if (PageGetFreeSpace (rpage )> itemsz || !keys_equal )
350- {
333+ /* if there is room here then we use this page. */
334+ else if (PageGetFreeSpace (rpage )> itemsz )
335+ use_left = false;
336+ }
337+ else /* rightmost page */
338+ {
339+ Assert ( !(rpageop -> btpo_flags & BTP_CHAIN ) );
340+ /* if there is room here then we use this page. */
341+ if (PageGetFreeSpace (rpage )> itemsz )
351342use_left = false;
352- break ;
353- }
354- /* try to move righter */
355- _bt_relbuf (rel ,buf ,BT_WRITE );
356- buf = rbuf ;
357- page = rpage ;
358- lpageop = rpageop ;
359343 }
360344if ( !use_left )/* insert on the right page */
361345 {
@@ -364,7 +348,6 @@ _bt_insertonpg(Relation rel,
364348scankey ,btitem ,afteritem ) );
365349 }
366350_bt_relbuf (rel ,rbuf ,BT_WRITE );
367- bknum = BufferGetBlockNumber (buf );
368351}
369352
370353/* split the buffer into left and right halves */