Completely remove the iScanRatio field. The PRAGMA index_list(TABLE) command

shows the estimated row size in the forth column.  It also generates a row
for the table with an index name of NULL.  The query planner still does not
take row size estimates into account - that is the next step.

FossilOrigin-Name: 8b4aa0c7a2122bbe60432edadf27e490e31ec987

manifest

@@ -1,5 +1,5 @@
-C Improvements\sto\sthe\sLogEst\scommand-line\stool\sused\sto\sconvert\sbetween\nordinary\snumbers\sand\sthe\sLogEst\srepresentation.
-D 2013-10-05T18:32:30.669
+C Completely\sremove\sthe\siScanRatio\sfield.\s\sThe\sPRAGMA\sindex_list(TABLE)\scommand\nshows\sthe\sestimated\srow\ssize\sin\sthe\sforth\scolumn.\s\sIt\salso\sgenerates\sa\srow\nfor\sthe\stable\swith\san\sindex\sname\sof\sNULL.\s\sThe\squery\splanner\sstill\sdoes\snot\ntake\srow\ssize\sestimates\sinto\saccount\s-\sthat\sis\sthe\snext\sstep.
+D 2013-10-05T19:18:00.706
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -157,7 +157,7 @@ F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
 F src/alter.c 2af0330bb1b601af7a7789bf7229675fd772a083
-F src/analyze.c c692855a5ba351ea2eddd916f7608fc28f09aa68
+F src/analyze.c 9f71f38700202b9c28153185b9d06fd4fe489cc9
 F src/attach.c 0a17c9364895316ca4f52d06a97a72c0af1ae8b3
 F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 2f1987981139bd2f6d8c728d64bf09fb387443c3
@@ -166,7 +166,7 @@ F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
 F src/btree.c 5ccbbaed7a32ba774306f610da4ab4f3e5348294
 F src/btree.h bfe0e8c5759b4ec77b0d18390064a6ef3cdffaaf
 F src/btreeInt.h f038e818bfadf75afbd09819ed93c26a333d39e0
-F src/build.c f92f1cd23ddb07b2aa84e21199bab97ad2da1144
+F src/build.c 3278345550d2b6cd9348d297f7acd22d900429eb
 F src/callback.c f99a8957ba2adf369645fac0db09ad8adcf1caa2
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c ea4b7f3623a0fcb1146e7f245d7410033e86859c
@@ -210,18 +210,18 @@ F src/parse.y a97566d6da75075589a7c716d1bda14b586cf8da
 F src/pcache.c f8043b433a57aba85384a531e3937a804432a346
 F src/pcache.h a5e4f5d9f5d592051d91212c5949517971ae6222
 F src/pcache1.c a467393909a4ed7ca9de066d85ba5c5b04a5be63
-F src/pragma.c 07814efdbf815356dafd4bfa4c21f527edbb0150
+F src/pragma.c c9a867f6f96934e91d3a07d72d1b8d61c9963008
 F src/prepare.c fa6988589f39af8504a61731614cd4f6ae71554f
 F src/printf.c da9119eb31a187a4b99f60aa4a225141c0ebb74b
 F src/random.c 0b2dbc37fdfbfa6bd455b091dfcef5bdb32dba68
 F src/resolve.c 7459801d02997b07e8b8da85ef255392ba1d022b
 F src/rowset.c 64655f1a627c9c212d9ab497899e7424a34222e0
-F src/select.c 6131008151ddc09bd04ceda98c3fcb8a36edacdd
+F src/select.c 13be733297f415b388444a2e296d23569cd83b8a
 F src/shell.c 5ee50ca3e35453bbd6ccdf1bdd0f6bbe9738e9fb
 F src/sqlite.h.in ec40aa958a270416fb04b4f72210357bf163d2c5
 F src/sqlite3.rc 11094cc6a157a028b301a9f06b3d03089ea37c3e
 F src/sqlite3ext.h 886f5a34de171002ad46fae8c36a7d8051c190fc
-F src/sqliteInt.h 75a6f6b26a91703672d62bd8df3bede2e6747e3b
+F src/sqliteInt.h 5dbfc960fb39dbb55ba16697f453b03cd759b04a
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac05a5c7017d0b9f0b4bcd701228b784f987158
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -290,7 +290,7 @@ F src/vtab.c 5a423b042eb1402ef77697d03d6a67378d97bc8d
 F src/wal.c 7dc3966ef98b74422267e7e6e46e07ff6c6eb1b4
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c e9e593d5bb798c3e67fc3893dfe7055c9e7d8d74
-F src/where.c 7b98d09e0e13179a8aeed38578434936369aa5c2
+F src/where.c 72c6c205e53ae72d2d235705bb2b040d70fff2e2
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
@@ -1121,7 +1121,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P 66c4a251d61582b47d5cbe50cbca160a9209bd06
-R 816e9739b4c9fe149e1a1ff9e9aba52e
+P 5252aeb61988e511dcf8d527fa81e51a5c9385f9
+R 0e3b98862666ae9510c1569ec248e564
 U drh
-Z 6ff6e983ab5701c81dead21480c8edfc
+Z 912eec158a04027b64a47b63c711b530

manifest.uuid

@@ -1 +1 @@
-5252aeb61988e511dcf8d527fa81e51a5c9385f9
+8b4aa0c7a2122bbe60432edadf27e490e31ec987

src/analyze.c

@@ -1277,17 +1277,10 @@ static void decodeIntArray(
   if( pIndex ){
     if( strcmp(z, "unordered")==0 ){
       pIndex->bUnordered = 1;
-    }else if( sqlite3_strglob("r=[0-9]*", z)==0 ){
+    }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
       int v32 = 0;
-      sqlite3GetInt32(z+2, &v32);
-      if( v32>=200 ){
-        v32 = 255;
-      }else if( v32<=0 ){
-        v32 = 1;
-      }else{
-        v32 = (128*v32)/100;
-      }
-      pIndex->iScanRatio = (u8)v32;
+      sqlite3GetInt32(z+3, &v32);
+      pIndex->szIdxRow = sqlite3LogEst(v32);
     }
   }
 }

src/build.c

@@ -1508,7 +1508,7 @@ static char *createTableStmt(sqlite3 *db, Table *p){
 /*
 ** Estimate the total row width for a table.
 */
-static unsigned estimatedTableWidth(const Table *pTab){
+static void estimateTableWidth(Table *pTab){
   unsigned wTable = 0;
   const Column *pTabCol;
   int i;
@@ -1516,15 +1516,13 @@ static unsigned estimatedTableWidth(const Table *pTab){
     wTable += pTabCol->szEst;
   }
   if( pTab->iPKey<0 ) wTable++;
-  return wTable;
+  pTab->szTabRow = sqlite3LogEst(wTable*4);
 }
 
 /*
-** Set the iScanRatio for an index based on estimates of the average
-** table row width and average index row width.  Estimates are derived
-** from the declared datatypes of the various columns.
+** Estimate the average size of a row for an index.
 */
-static void setIndexScanRatio(Index *pIdx, unsigned wTable){
+static void estimateIndexWidth(Index *pIdx){
   unsigned wIndex = 1;
   int i;
   const Column *aCol = pIdx->pTable->aCol;
@@ -1532,10 +1530,7 @@ static void setIndexScanRatio(Index *pIdx, unsigned wTable){
     assert( pIdx->aiColumn[i]>=0 && pIdx->aiColumn[i]<pIdx->pTable->nCol );
     wIndex += aCol[pIdx->aiColumn[i]].szEst;
   }
-  assert( 100*wIndex/wTable <= 255 );
-  pIdx->iScanRatio = (u8)(128*wIndex/wTable);
-  /* printf("%s: wIndex=%d wTable=%d ratio=%d\n",
-  ** pIdx->zName, wIndex, wTable, (100*pIdx->iScanRatio)/128); */
+  pIdx->szIdxRow = sqlite3LogEst(wIndex*4);
 }
 
 /*
@@ -1588,10 +1583,10 @@ void sqlite3EndTable(
   }
 #endif /* !defined(SQLITE_OMIT_CHECK) */
 
-  /* Compute the iScanRatio of implied indices */
-  wTable = estimatedTableWidth(p);
+  /* Estimate the average row size for the table and for all implied indices */
+  estimateTableWidth(p);
   for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
-    setIndexScanRatio(pIdx, wTable);
+    estimateIndexWidth(pIdx);
   }
 
   /* If the db->init.busy is 1 it means we are reading the SQL off the
@@ -2818,9 +2813,7 @@ Index *sqlite3CreateIndex(
     if( pTab->aCol[j].notNull==0 ) pIndex->uniqNotNull = 0;
   }
   sqlite3DefaultRowEst(pIndex);
-  if( pParse->pNewTable==0 ){
-    setIndexScanRatio(pIndex, estimatedTableWidth(pTab));
-  }
+  if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);
 
   if( pTab==pParse->pNewTable ){
     /* This routine has been called to create an automatic index as a

src/pragma.c

@@ -1449,28 +1449,30 @@ void sqlite3Pragma(
   case PragTyp_INDEX_LIST: if( zRight ){
     Index *pIdx;
     Table *pTab;
+    int i;
     pTab = sqlite3FindTable(db, zRight, zDb);
     if( pTab ){
       v = sqlite3GetVdbe(pParse);
-      pIdx = pTab->pIndex;
-      if( pIdx ){
-        int i = 0; 
-        sqlite3VdbeSetNumCols(v, 4);
-        pParse->nMem = 4;
-        sqlite3CodeVerifySchema(pParse, iDb);
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "r", SQLITE_STATIC);
-        while(pIdx){
-          sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-          sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
-          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
-          sqlite3VdbeAddOp2(v, OP_Integer, (pIdx->iScanRatio*100+127)/128, 4);
-          sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
-          ++i;
-          pIdx = pIdx->pNext;
-        }
+      sqlite3VdbeSetNumCols(v, 4);
+      pParse->nMem = 4;
+      sqlite3CodeVerifySchema(pParse, iDb);
+      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
+      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
+      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC);
+      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "avgrowsize", SQLITE_STATIC);
+      sqlite3VdbeAddOp2(v, OP_Integer, 0, 1);
+      sqlite3VdbeAddOp2(v, OP_Null, 0, 2);
+      sqlite3VdbeAddOp2(v, OP_Integer, 1, 3);
+      sqlite3VdbeAddOp2(v, OP_Integer,
+                           (int)sqlite3LogEstToInt(pTab->szTabRow), 4);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
+      for(pIdx=pTab->pIndex, i=1; pIdx; pIdx=pIdx->pNext, i++){
+        sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
+        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
+        sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
+        sqlite3VdbeAddOp2(v, OP_Integer,
+                             (int)sqlite3LogEstToInt(pIdx->szIdxRow), 4);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
       }
     }
   }

src/select.c

@@ -4608,9 +4608,9 @@ int sqlite3Select(
         */
         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
           if( pIdx->bUnordered==0
-           && pIdx->iScanRatio<128
+           && pIdx->szIdxRow<pTab->szTabRow
            && pIdx->pPartIdxWhere==0
-           && (!pBest || pIdx->iScanRatio<pBest->iScanRatio)
+           && (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
           ){
             pBest = pIdx;
           }

src/sqliteInt.h

@@ -1588,7 +1588,6 @@ struct Index {
   int tnum;                /* DB Page containing root of this index */
   LogEst szIdxRow;         /* Estimated average row size in bytes */
   u16 nColumn;             /* Number of columns in table used by this index */
-  u8 iScanRatio;           /* Scan rate relative to the main table */
   u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
   unsigned autoIndex:2;    /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
   unsigned bUnordered:1;   /* Use this index for == or IN queries only */

src/where.c

@@ -4569,7 +4569,7 @@ static int whereLoopAddBtree(
       pNew->iSortIdx = b ? iSortIdx : 0;
       /* TUNING: Cost of full table scan is 3*(N + log2(N)).
       **  +  The extra 3 factor is to encourage the use of indexed lookups
-      **     over full scans. */
+      **     over full scans.  FIXME */
       pNew->rRun = sqlite3LogEstAdd(rSize,rLogSize) + 16;
       whereLoopOutputAdjust(pWC, pNew, pSrc->iCursor);
       rc = whereLoopInsert(pBuilder, pNew);
@@ -4583,7 +4583,6 @@ static int whereLoopAddBtree(
       if( b
        || ( m==0
          && pProbe->bUnordered==0
-         && pProbe->iScanRatio<128
          && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
          && sqlite3GlobalConfig.bUseCis
          && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
@@ -4594,9 +4593,9 @@ static int whereLoopAddBtree(
           /* TUNING: Cost of a covering index scan is K*(N + log2(N)).
           **  +  The extra factor K of between 1.1 (iScanRatio between 0
           **     and 9) and 2.8 (iScanRatio between 126 and 127) is added
-          **     to encourage the use of indexed lookups.
+          **     to encourage the use of indexed lookups.  FIXME
           */
-          pNew->rRun = sqlite3LogEstAdd(rSize,rLogSize) + pProbe->iScanRatio/9 + 1;
+          pNew->rRun = sqlite3LogEstAdd(rSize,rLogSize) + 10;
         }else{
           assert( b!=0 ); 
           /* TUNING: Cost of scanning a non-covering index is (N+1)*log2(N)