B-tree optimization: When seeking on a rowid table that has already been

positioned, check to see if the new row happens to be the next row on the
same leaf page.  That is a reasonably common case, and if it is true it
avoids a full binary search.

FossilOrigin-Name: 8e5cfb2039126da7689c4b1c88760f10e1234eaf

1 files changed, 15 insertions, 3 deletions

diff --git a/src/btree.c b/src/btree.c
index fb0565591..8b095b57b 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -5091,9 +5091,21 @@ int sqlite3BtreeMovetoUnpacked(
       *pRes = 0;
       return SQLITE_OK;
     }
-    if( (pCur->curFlags & BTCF_AtLast)!=0 && pCur->info.nKey<intKey ){
-      *pRes = -1;
-      return SQLITE_OK;
+    if( pCur->info.nKey<intKey ){
+      if( (pCur->curFlags & BTCF_AtLast)!=0 ){
+        *pRes = -1;
+        return SQLITE_OK;
+      }
+      if( pCur->aiIdx[pCur->iPage]+1<pCur->apPage[pCur->iPage]->nCell ){
+        pCur->aiIdx[pCur->iPage]++;
+        pCur->info.nSize = 0;
+        pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
+        getCellInfo(pCur);
+        if( pCur->info.nKey==intKey ){
+          *pRes = 0;
+          return SQLITE_OK;
+        }
+      }
     }
   }