From: drh <drh@noemail.net>
Date: Fri, 2 Oct 2020 13:57:13 +0000 (+0000)
Subject: Import further corner-case fixes for the in-scan-vs-index or OP_SeekScan
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e1436fcad9c04a18242c688d19fbf00a77bcb862;p=thirdparty%2Fsqlite.git

Import further corner-case fixes for the in-scan-vs-index or OP_SeekScan
optimization from trunk.

FossilOrigin-Name: c144d6404ff122d6a92d59fed09fab9a0a592e4dab771ef41b0db3535359f1d6
---

diff --git a/manifest b/manifest
index b006f18956..b523761a74 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C For\sthe\sOP_SeekScan\soptimization,\sthe\sOP_IdxGT\sdoes\snot\snecessarily\scome\nright\safter\sthe\sOP_SeekGE.\s\s\sSo\suse\sthe\sP2\soperand\sof\sOP_SeekScan\sto\spoint\nto\sthe\sfirst\sinstruction\safter\sOP_IdxGT.\s\sProblem\sfound\sby\sdbsqlfuzz.
-D 2020-10-02T12:11:30.506
+C Import\sfurther\scorner-case\sfixes\sfor\sthe\sin-scan-vs-index\sor\sOP_SeekScan\noptimization\sfrom\strunk.
+D 2020-10-02T13:57:13.021
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -590,7 +590,7 @@ F src/upsert.c 0dd81b40206841814d46942a7337786932475f085716042d0cb2fc7791bf8ca4
 F src/utf.c 2f0fac345c7660d5c5bd3df9e9d8d33d4c27f366bcfb09e07443064d751a0507
 F src/util.c e12939405e77906d06ab0b78c5f513dcd2b7cec2fbb553877b0abfece6067141
 F src/vacuum.c 72690ccb6877a88f8473a893cf9f6d7592236f3eebfebfa840b19c708acde574
-F src/vdbe.c d5d6082900165119a7e2064d312f533e8859491ada725ce8240643866871e0d8
+F src/vdbe.c c80fd12dc2b291f6650c272ccec8b7f0607f6972744efbfba2fa79674bb3db87
 F src/vdbe.h 712bca562eaed1c25506b9faf9680bdc75fc42e2f4a1cd518d883fa79c7a4237
 F src/vdbeInt.h 1a928793190675799194bdee2778f13b10ee42bc20bc03b6635687e4d3d80874
 F src/vdbeapi.c 2ddd60f4a351f15ee98d841e346af16111ad59dfa4d25d2dd4012e9875bf7d92
@@ -604,9 +604,9 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 9eccc7ebb532a7b0fd3cabc16cff576b9afa763472272db67d84fb8cec96f5c0
 F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
 F src/walker.c 7607f1a68130c028255d8d56094ea602fc402c79e1e35a46e6282849d90d5fe4
-F src/where.c 4604336992184fa80fe9a8b176d18cb5c6b6e78f70b21f5d826d50275ed34791
+F src/where.c 9030f0f4d674d9099932ed7913eb1f8ddd58acc6cfea893deec7efa76fc44d13
 F src/whereInt.h bcbba483d0cd72c17ab9af97061dce3c00eb3695cd17a5d41cdfec2cb5a6e8ce
-F src/wherecode.c e9958d23b3888b1c7f926c9234c3d96485e7b389d4a3e8aa83d5be4643d3c8af
+F src/wherecode.c 5e0b6dec8591e13f1f0af828d350e4a5dd2e3518b63d328f21bb38e2456dfeb7
 F src/whereexpr.c 90859652920f153d2c03f075488744be2926625ebd36911bcbcb17d0d29c891c
 F src/window.c 038c248267e74ff70a2bb9b1884d40fd145c5183b017823ecb6cbb14bc781478
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
@@ -1819,8 +1819,9 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 9a1cdf7e9c79689aa80a2d5bbfaee04e20f288466eac0709c981f3fef7d19a03
-Q +091d71939411bf2079098f09ddc0525f11f380119fd27114e2b3eec9a8ac0db4
-R e61d5a4ef6ff291cc7036774b1744aae
+P ec37744c6ea61f94bb850875f9ac86e80ac0c111bc5a2c2eb2050897ec1e63cd
+Q +ad5ab24ebd557e7af1d92ab3fbcb3747c04da5ad4ed779fb6391dc94042687dd
+Q +c0400f8c0bcb85ba39004feff753eae2f8e82065539e52b5788febd7644c417b
+R ed40b319cb8ff5e5e2a58c08d4ee2c80
 U drh
-Z 19c62bd990007dbf46dc3b1158f6b62a
+Z 61ad1955920a3fa1588d272c2f0c8015
diff --git a/manifest.uuid b/manifest.uuid
index 5ce1e1a225..7834e50633 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-ec37744c6ea61f94bb850875f9ac86e80ac0c111bc5a2c2eb2050897ec1e63cd
\ No newline at end of file
+c144d6404ff122d6a92d59fed09fab9a0a592e4dab771ef41b0db3535359f1d6
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index aba21cfe43..44558ce84c 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -4168,7 +4168,6 @@ case OP_SeekScan: {
   assert( pOp[1].p1==aOp[pOp->p2-1].p1 );
   assert( pOp[1].p2==aOp[pOp->p2-1].p2 );
   assert( pOp[1].p3==aOp[pOp->p2-1].p3 );
-  assert( pOp[1].p4.i==aOp[pOp->p2-1].p4.i );
 
   assert( pOp->p1>0 );
   pC = p->apCsr[pOp[1].p1];
diff --git a/src/where.c b/src/where.c
index 8efcb475c1..d907bd18e6 100644
--- a/src/where.c
+++ b/src/where.c
@@ -2526,7 +2526,7 @@ static int whereLoopAddBtreeIndex(
         assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
                           ** changes "x IN (?)" into "x=?". */
       }
-      if( pProbe->hasStat1 ){
+      if( pProbe->hasStat1 && rLogSize>=10 ){
         LogEst M, logK, safetyMargin;
         /* Let:
         **   N = the total number of rows in the table
@@ -2545,7 +2545,8 @@ static int whereLoopAddBtreeIndex(
         ** a safety margin of 2 (LogEst: 10) that favors using the IN operator
         ** with the index, as using an index has better worst-case behavior.
         ** If we do not have real sqlite_stat1 data, always prefer to use
-        ** the index.
+        ** the index.  Do not bother with this optimization on very small
+        ** tables (less than 2 rows) as it is pointless in that case.
         */
         M = pProbe->aiRowLogEst[saved_nEq];
         logK = estLog(nIn);
diff --git a/src/wherecode.c b/src/wherecode.c
index e49cf2deaf..6f2607692a 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -1690,12 +1690,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
     }else{
       op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
       assert( op!=0 );
-      assert( op==OP_SeekGE
-           || (pLoop->wsFlags & WHERE_IN_SEEKSCAN)==0
-           || (db->flags & SQLITE_ReverseOrder)!=0 );
-      if( (pLoop->wsFlags & WHERE_IN_SEEKSCAN)!=0
-       && op==OP_SeekGE            /* OP_SeekScan only does forward scans */
-      ){
+      if( (pLoop->wsFlags & WHERE_IN_SEEKSCAN)!=0 && op==OP_SeekGE ){
         /* TUNING:  The OP_SeekScan opcode seeks to reduce the number
         ** of expensive seek operations by replacing a single seek with
         ** 1 or more step operations.  The question is, how many steps