From: drh <drh@noemail.net>
Date: Sat, 21 Jan 2017 21:47:54 +0000 (+0000)
Subject: A better implementation of the moveto-neighbor optimization that checks for
X-Git-Tag: version-3.17.0~82^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7f11afaba17fdc24ef01775613e4052a4100bbcf;p=thirdparty%2Fsqlite.git

A better implementation of the moveto-neighbor optimization that checks for
nearby rows on adjacent pages.

FossilOrigin-Name: 2c4ecb85a475b9063aa8a3bb517ac181a7ded649
---

diff --git a/manifest b/manifest
index cbd159d22a..95352ee96a 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C B-tree\soptimization:\s\sWhen\sseeking\son\sa\srowid\stable\sthat\shas\salready\sbeen\npositioned,\scheck\sto\ssee\sif\sthe\snew\srow\shappens\sto\sbe\sthe\snext\srow\son\sthe\nsame\sleaf\spage.\s\sThat\sis\sa\sreasonably\scommon\scase,\sand\sif\sit\sis\strue\sit\navoids\sa\sfull\sbinary\ssearch.
-D 2017-01-21T16:54:19.338
+C A\sbetter\simplementation\sof\sthe\smoveto-neighbor\soptimization\sthat\schecks\sfor\nnearby\srows\son\sadjacent\spages.
+D 2017-01-21T21:47:54.621
 F Makefile.in 41bd4cad981487345c4a84081074bcdb876e4b2e
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@@ -333,7 +333,7 @@ F src/auth.c 930b376a9c56998557367e6f7f8aaeac82a2a792
 F src/backup.c faf17e60b43233c214aae6a8179d24503a61e83b
 F src/bitvec.c 17ea48eff8ba979f1f5b04cc484c7bb2be632f33
 F src/btmutex.c 0e9ce2d56159b89b9bc8e197e023ee11e39ff8ca
-F src/btree.c 972b7e1346eb2f4369cf8cc43117c728e2bd9cd4
+F src/btree.c f1b36bcfb1f9532ce64fe534153f11b8e2595d8b
 F src/btree.h e6d352808956ec163a17f832193a3e198b3fb0ac
 F src/btreeInt.h 10c4b77c2fb399580babbcc7cf652ac10dba796e
 F src/build.c 9e799f1edd910dfa8a0bc29bd390d35d310596af
@@ -1547,7 +1547,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 347df3c1fd7322e7aacaf1e9f8be81830947c482
-R 3888200d85fb0a6e771ec0a3c9f2e5a8
+P 8e5cfb2039126da7689c4b1c88760f10e1234eaf
+R 9f1865839aca85688e5829c506350f09
 U drh
-Z 4b0826cf6fb92296cc5aa9f45d953141
+Z fbf63ba541a6f5ec3e59c684016e63a0
diff --git a/manifest.uuid b/manifest.uuid
index ac357ef297..478c310b27 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-8e5cfb2039126da7689c4b1c88760f10e1234eaf
\ No newline at end of file
+2c4ecb85a475b9063aa8a3bb517ac181a7ded649
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 8b095b57b0..b6bc66ea85 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -5096,14 +5096,19 @@ int sqlite3BtreeMovetoUnpacked(
         *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;
+      /* If the requested key is one more than the previous key, then
+      ** try to get there using sqlite3BtreeNext() rather than a full
+      ** binary search.  This is an optimization only.  The correct answer
+      ** is still obtained without this ase, only a little more slowely */
+      if( pCur->info.nKey+1==intKey && !pCur->skipNext ){
+        *pRes = 0;
+        rc = sqlite3BtreeNext(pCur, pRes);
+        if( rc ) return rc;
+        if( *pRes==0 ){
+          getCellInfo(pCur);
+          if( pCur->info.nKey==intKey ){
+            return SQLITE_OK;
+          }
         }
       }
     }