Progress toward decending indices. (CVS 2839)

FossilOrigin-Name: 112a34b8dcceb39540cb0cd629e264a867400bfb

diff --git a/manifest b/manifest
index e400b55a20f8d6f8f055ae43eecc226c492f5829..898f81d356128ef49e3b233d7350a1c65a1184b0 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Include\ssqlite3_release_memory()\scode\swhen\sSQLITE_MEMDEBUG\sis\snot\sdefined.\s(CVS\s2838)
-D 2005-12-20T14:38:00
+C Progress\stoward\sdecending\sindices.\s(CVS\s2839)
+D 2005-12-21T03:16:43
 F Makefile.in e3c6b3a38d734d41574c04f2fc90d18de2b87102
 F Makefile.linux-gcc aee18d8a05546dcf1888bd4547e442008a49a092
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -36,7 +36,7 @@ F src/attach.c ee70131f128d31a9c6dcb8824e8471c91b18601a
 F src/auth.c 31e2304bef67f44d635655f44234387ea7d21454
 F src/btree.c 300fd8342f4d9f75829a8a96d60578592f3dee79
 F src/btree.h 8ff86378bb5af0cde282614c16bf0c0190b6d216
-F src/build.c 178a5c36365b5ec89a4a29a74186583f503c10fa
+F src/build.c 502479f9b9b5cc0f7f629289f82e98c54c1789d5
 F src/callback.c 62066afd516f220575e81b1a1239ab92a2eae252
 F src/complete.c df1681cef40dec33a286006981845f87b194e7a4
 F src/date.c bb079317bff6a2b78aba5c0d2ddae5f6f03acfb7
@@ -91,7 +91,7 @@ F src/vdbeapi.c b270b680cbc5d20b5a1abfdb08339667985df94e
 F src/vdbeaux.c c38276e0c95d9ed9c35bab195faea3d57e787aea
 F src/vdbefifo.c 9efb94c8c3f4c979ebd0028219483f88e57584f5
 F src/vdbemem.c deba8d6e3727643924b210a8c531a496c2b8d386
-F src/where.c 269569f380ddc018518f67765fe2f0d3c8760e28
+F src/where.c 4db62a60cda1c267947b975daf177b3c99e90d2b
 F tclinstaller.tcl 046e3624671962dc50f0481d7c25b38ef803eb42
 F test/all.test 55706917a12cd616440d50c35323747b4a9f03c3
 F test/alter.test 9d6837a3d946b73df692b7cef2a7644d2e2f6bc6
@@ -329,7 +329,7 @@ F www/tclsqlite.tcl ddcf912ea48695603c8ed7efb29f0812ef8d1b49
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P c2c5285442f4558dfca61b52f31b5a9cbefaed10
-R c41e18b7f54b841b391c4a1c2c7de45d
-U danielk1977
-Z 694bd7f2618622c7a35a61895f0abc86
+P 77a37ceca7792e6cda6810e3387e6dda14a5c7ec
+R 72d096b7221b434491091a1e91cf3acd
+U drh
+Z db01996f6f52833d4c472a9960d2c37e

diff --git a/manifest.uuid b/manifest.uuid
index 32b49ebf0e5bc12b1c066ea0ea6e0b785cc12bc9..f358883775062d85b6ea1926807f5717fcd8a228 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-77a37ceca7792e6cda6810e3387e6dda14a5c7ec
\ No newline at end of file
+112a34b8dcceb39540cb0cd629e264a867400bfb
\ No newline at end of file

diff --git a/src/build.c b/src/build.c
index 32d4bfd05477238d22a249932798b56c041fb4bb..f771fb689c49346ccae8ba501709fa9bb0f41707 100644 (file)
--- a/src/build.c
+++ b/src/build.c
@@ -22,7 +22,7 @@
 **     COMMIT
 **     ROLLBACK
 **
-** $Id: build.c,v 1.358 2005/12/16 01:06:17 drh Exp $
+** $Id: build.c,v 1.359 2005/12/21 03:16:43 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -2113,7 +2113,6 @@ void sqlite3CreateIndex(
   int iDb;             /* Index of the database that is being written */
   Token *pName = 0;    /* Unqualified name of the index to create */
   struct ExprList_item *pListItem; /* For looping over pList */
-  CollSeq *pCollSeq;               /* Collating sequence for one index column */
 
   if( pParse->nErr || sqlite3Tsd()->mallocFailed ) goto exit_create_index;
 
@@ -2277,7 +2276,7 @@ void sqlite3CreateIndex(
   for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
     const char *zColName = pListItem->zName;
     Column *pTabCol;
-    int sortOrder;
+    int requestedSortOrder;
     for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
       if( sqlite3StrICmp(zColName, pTabCol->zName)==0 ) break;
     }
@@ -2299,11 +2298,11 @@ void sqlite3CreateIndex(
     ){
       goto exit_create_index;
     }
-    sortOrder = pListItem->sortOrder;
-    pDb->descIndex |= sortOrder;
-    sortOrder &= sortOrderMask;
-    pIndex->keyInfo.aSortOrder[i] = sortOrder;
-    descSeen |= sortOrder;
+    requestedSortOrder = pListItem->sortOrder;
+    pDb->descIndex |= requestedSortOrder;
+    requestedSortOrder &= sortOrderMask;
+    pIndex->keyInfo.aSortOrder[i] = requestedSortOrder;
+    descSeen |= requestedSortOrder;
   }
   pIndex->keyInfo.nField = pList->nExpr;
   sqlite3DefaultRowEst(pIndex);

diff --git a/src/where.c b/src/where.c
index d643bde05ff3f847e18a9fd052f0925ab84dc6e9..71ad86ef16bd8b9c24799c626b89d518334dc14d 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -16,7 +16,7 @@
 ** so is applicable.  Because this module is responsible for selecting
 ** indices, you might also think of this module as the "query optimizer".
 **
-** $Id: where.c,v 1.187 2005/12/07 06:27:44 danielk1977 Exp $
+** $Id: where.c,v 1.188 2005/12/21 03:16:43 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -785,7 +785,7 @@ static int isSortingIndex(
   int *pbRev              /* Set to 1 if ORDER BY is DESC */
 ){
   int i, j;                       /* Loop counters */
-  int sortOrder = SQLITE_SO_ASC;  /* Which direction we are sorting */
+  int sortOrder = 0;              /* XOR of index and ORDER BY sort direction */
   int nTerm;                      /* Number of ORDER BY terms */
   struct ExprList_item *pTerm;    /* A term of the ORDER BY clause */
   sqlite3 *db = pParse->db;
@@ -800,6 +800,7 @@ static int isSortingIndex(
   for(i=j=0, pTerm=pOrderBy->a; j<nTerm && i<pIdx->nColumn; i++){
     Expr *pExpr;       /* The expression of the ORDER BY pTerm */
     CollSeq *pColl;    /* The collating sequence of pExpr */
+    int termSortOrder; /* Sort order for this term */
 
     pExpr = pTerm->pExpr;
     if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
@@ -823,14 +824,18 @@ static int isSortingIndex(
         return 0;
       }
     }
+    assert( pIdx->keyInfo.aSortOrder!=0 );
+    assert( pTerm->sortOrder==0 || pTerm->sortOrder==1 );
+    assert( pIdx->keyInfo.aSortOrder[i]==0 || pIdx->keyInfo.aSortOrder[i]==1 );
+    termSortOrder = pIdx->keyInfo.aSortOrder[i] ^ pTerm->sortOrder;
     if( i>nEqCol ){
-      if( pTerm->sortOrder!=sortOrder ){
+      if( termSortOrder!=sortOrder ){
         /* Indices can only be used if all ORDER BY terms past the
         ** equality constraints are all either DESC or ASC. */
         return 0;
       }
     }else{
-      sortOrder = pTerm->sortOrder;
+      sortOrder = termSortOrder;
     }
     j++;
     pTerm++;
@@ -840,7 +845,7 @@ static int isSortingIndex(
   ** are covered.
   */
   if( j>=nTerm ){
-    *pbRev = sortOrder==SQLITE_SO_DESC;
+    *pbRev = sortOrder!=0;
     return 1;
   }
   return 0;
@@ -1710,7 +1715,9 @@ WhereInfo *sqlite3WhereBegin(
       */
       int start;
       int nEq = pLevel->nEq;
-      int leFlag=0, geFlag=0;
+      int topEq=0;        /* True if top limit uses ==. False is strictly < */
+      int btmEq=0;        /* True if btm limit uses ==. False if strictly > */
+      int topOp, btmOp;   /* Operators for the top and bottom search bounds */
       int testOp;
       int topLimit = (pLevel->flags & WHERE_TOP_LIMIT)!=0;
       int btmLimit = (pLevel->flags & WHERE_BTM_LIMIT)!=0;
@@ -1728,6 +1735,20 @@ WhereInfo *sqlite3WhereBegin(
         sqlite3VdbeAddOp(v, OP_Dup, nEq-1, 0);
       }
 
+      /* Figure out what comparison operators to use for top and bottom 
+      ** search bounds. For an ascending index, the bottom bound is a > or >=
+      ** operator and the top bound is a < or <= operator.  For a descending
+      ** index the operators are reversed.
+      */
+      if( pIdx->keyInfo.aSortOrder[nEq]==SQLITE_SO_ASC ){
+        topOp = WO_LT|WO_LE;
+        btmOp = WO_GT|WO_GE;
+      }else{
+        topOp = WO_GT|WO_GE;
+        btmOp = WO_LT|WO_LE;
+        SWAP(int, topLimit, btmLimit);
+      }
+
       /* Generate the termination key.  This is the key value that
       ** will end the search.  There is no termination key if there
       ** are no equality terms and no "X<..." term.
@@ -1738,24 +1759,24 @@ WhereInfo *sqlite3WhereBegin(
       if( topLimit ){
         Expr *pX;
         int k = pIdx->aiColumn[j];
-        pTerm = findTerm(&wc, iCur, k, notReady, WO_LT|WO_LE, pIdx);
+        pTerm = findTerm(&wc, iCur, k, notReady, topOp, pIdx);
         assert( pTerm!=0 );
         pX = pTerm->pExpr;
         assert( (pTerm->flags & TERM_CODED)==0 );
         sqlite3ExprCode(pParse, pX->pRight);
-        leFlag = pX->op==TK_LE;
+        topEq = pTerm->operator & (WO_LE|WO_GE);
         disableTerm(pLevel, pTerm);
         testOp = OP_IdxGE;
       }else{
         testOp = nEq>0 ? OP_IdxGE : OP_Noop;
-        leFlag = 1;
+        topEq = 1;
       }
       if( testOp!=OP_Noop ){
         int nCol = nEq + topLimit;
         pLevel->iMem = pParse->nMem++;
         buildIndexProbe(v, nCol, brk, pIdx);
         if( bRev ){
-          int op = leFlag ? OP_MoveLe : OP_MoveLt;
+          int op = topEq ? OP_MoveLe : OP_MoveLt;
           sqlite3VdbeAddOp(v, op, iIdxCur, brk);
         }else{
           sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
@@ -1776,15 +1797,15 @@ WhereInfo *sqlite3WhereBegin(
       if( btmLimit ){
         Expr *pX;
         int k = pIdx->aiColumn[j];
-        pTerm = findTerm(&wc, iCur, k, notReady, WO_GT|WO_GE, pIdx);
+        pTerm = findTerm(&wc, iCur, k, notReady, btmOp, pIdx);
         assert( pTerm!=0 );
         pX = pTerm->pExpr;
         assert( (pTerm->flags & TERM_CODED)==0 );
         sqlite3ExprCode(pParse, pX->pRight);
-        geFlag = pX->op==TK_GE;
+        btmEq = pTerm->operator & (WO_LE|WO_GE);
         disableTerm(pLevel, pTerm);
       }else{
-        geFlag = 1;
+        btmEq = 1;
       }
       if( nEq>0 || btmLimit ){
         int nCol = nEq + btmLimit;
@@ -1794,7 +1815,7 @@ WhereInfo *sqlite3WhereBegin(
           sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
           testOp = OP_IdxLT;
         }else{
-          int op = geFlag ? OP_MoveGe : OP_MoveGt;
+          int op = btmEq ? OP_MoveGe : OP_MoveGt;
           sqlite3VdbeAddOp(v, op, iIdxCur, brk);
         }
       }else if( bRev ){
@@ -1811,7 +1832,7 @@ WhereInfo *sqlite3WhereBegin(
       if( testOp!=OP_Noop ){
         sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
         sqlite3VdbeAddOp(v, testOp, iIdxCur, brk);
-        if( (leFlag && !bRev) || (!geFlag && bRev) ){
+        if( (topEq && !bRev) || (!btmEq && bRev) ){
           sqlite3VdbeChangeP3(v, -1, "+", P3_STATIC);
         }
       }