Add the SQLITE_SCANSTAT_SELECTID metric. Use it to improve the

".stmtscan on" output in the shell.

FossilOrigin-Name: 64ad5761a841f71530d41565b9fbe9d19c2d6aff

manifest

@@ -1,5 +1,5 @@
-C Change\sthe\sSQLITE_SCANSTAT_EST\sparameter\sso\sthat\sit\sreturns\sa\sdouble\sfor\nthe\sestimated\snumber\sof\soutput\srows\sper\sloop,\srather\sthan\sa\s64-bit\sinteger.\nRevise\sthe\soutput\sformat\sfor\sthe\s".scanstats\son"\sin\sthe\sshell\sto\smake\suse\nof\sthis\snew\scapability.
-D 2014-11-06T03:55:10.745
+C Add\sthe\sSQLITE_SCANSTAT_SELECTID\smetric.\s\sUse\sit\sto\simprove\sthe\n".stmtscan\son"\soutput\sin\sthe\sshell.
+D 2014-11-06T04:42:20.310
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in cf57f673d77606ab0f2d9627ca52a9ba1464146a
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -228,8 +228,8 @@ F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c 4965007d6497b6a4d7a6d98751cc39712885f952
 F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
 F src/select.c 428165951748151e87a15295b7357221433e311b
-F src/shell.c 908ff96ef1551b28b940aaf4c886ba2681057209
-F src/sqlite.h.in e13a7b64efa8d6a591577e6a5281fb22783c0133
+F src/shell.c 74768f90bd0f8880937d52e2eb756655dba0015a
+F src/sqlite.h.in 087d30a4c7ec7ae19bcaa03a9db9d6ee7a73b0b3
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h 17d487c3c91b0b8c584a32fbeb393f6f795eea7d
 F src/sqliteInt.h 8f67ca79e957b8ece7453b8e320b6a996e1b4761
@@ -291,8 +291,8 @@ F src/util.c 3b627daa45c7308c1e36e3dbaa3f9ce7e5c7fa73
 F src/vacuum.c 59f03f92bcff57faa6a8ca256eb29ccddfb0614a
 F src/vdbe.c 3fd4ebd3e87b63175bfd2be747608bae1670b4df
 F src/vdbe.h 6fc69d9c5e146302c56e163cb4b31d1ee64a18c3
-F src/vdbeInt.h c32c1de25e3821a5b53d73abdb23ccc644ec5b63
-F src/vdbeapi.c 6a126fd8ed297ff0542bfbf7891b92977b5ed653
+F src/vdbeInt.h 9bb69ff2447c34b6ccc58b34ec35b615f86ead78
+F src/vdbeapi.c 07acb615d1e4170e71fc1b0d087f3c53a1ad8e83
 F src/vdbeaux.c 9b0a251b6dfab349dd6c6efb40062eb7386b26f5
 F src/vdbeblob.c 8b5442ff0954c44b45cbabbe2e94091a2e16fdef
 F src/vdbemem.c 31d8eabb0cd78bfeab4e5124c7363c3e9e54db9f
@@ -1211,10 +1211,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 272fddc14cc322655eeba670bc0f9fc30e5a804c
-R c0f850c2227a7a137fbc73d5c1c5136e
-T *branch * scanstatus
-T *sym-scanstatus *
-T -sym-trunk *
+P f9684000665ae7ef6f89c3773612b8286b8f545a
+R 34f47ade33b56f41a439ae08635a112b
 U drh
-Z f39cd1607e4aacbb491c044bd0bb317e
+Z 216d325be8d3eddf6fd433a7ff464585

manifest.uuid

@@ -1 +1 @@
-f9684000665ae7ef6f89c3773612b8286b8f545a
+64ad5761a841f71530d41565b9fbe9d19c2d6aff

src/shell.c

@@ -1195,12 +1195,14 @@ static void display_scanstats(
 ){
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
   int i;
-  double rEstLoop = 1.0;
+  double *arEstLoop = 0;
+  int nEstLoop = 0;
   fprintf(pArg->out, "-------- scanstats --------\n");
   for(i=0; 1; i++){
     sqlite3_stmt *p = pArg->pStmt;
     sqlite3_int64 nLoop, nVisit;
-    double rEst;
+    double rEst, rLoop;
+    int iSid;
     const char *zExplain;
     if( sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_NLOOP, (void*)&nLoop) ){
       break;
@@ -1208,13 +1210,23 @@ static void display_scanstats(
     sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_NVISIT, (void*)&nVisit);
     sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_EST, (void*)&rEst);
     sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_EXPLAIN, (void*)&zExplain);
-
+    sqlite3_stmt_scanstatus(p, i, SQLITE_SCANSTAT_SELECTID, (void*)&iSid);
+    if( iSid>=nEstLoop ){
+      arEstLoop = sqlite3_realloc(arEstLoop, sizeof(arEstLoop[0])*(iSid+1) );
+      while( nEstLoop<=iSid ) arEstLoop[nEstLoop++] = 1.0; 
+    }
+    if( iSid>=0 ){
+      arEstLoop[iSid] *= rEst;
+      rLoop = arEstLoop[iSid];
+    }else{
+      rLoop = rEst;
+    }
     fprintf(pArg->out, "Loop %2d: \"%s\"\n", i, zExplain);
-    rEstLoop *= rEst;
     fprintf(pArg->out, "        nLoop=%-8lld nRow=%-8lld estRow=%-8lld estRow/Loop=%-8g\n",
-        nLoop, nVisit, (sqlite3_int64)rEstLoop, rEst
+        nLoop, nVisit, (sqlite3_int64)rLoop, rEst
     );
   }
+  sqlite3_free(arEstLoop);
 #else
   fprintf(pArg->out, "-------- scanstats --------\n");
   fprintf(pArg->out,

src/sqlite.h.in

@@ -7447,8 +7447,8 @@ int sqlite3_vtab_on_conflict(sqlite3 *);
 ** query planner's estimate for the average number of rows output from each
 ** iteration of the X-th loop.  If the query planner's estimates was accurate,
 ** then this value will approximate the quotient NVISIT/NLOOP and the
-** product of this value for the first N-1 loops will approximate
-** the NLOOP value for the N-th loop.
+** product of this value for all prior loops with the same SELECTID will
+** be the NLOOP value for the current loop.
 **
 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
 ** <dd>^The "const char *" variable pointed to by the T parameter will be set to 
@@ -7459,6 +7459,13 @@ int sqlite3_vtab_on_conflict(sqlite3 *);
 ** <dd>^The "const char *" variable pointed to by the T parameter will be set to 
 ** a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] description
 ** for the X-th loop.
+**
+** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
+** <dd>^The "int" variable pointed to by the T parameter will be set to the
+** "select-id" for the X-th loop.  The select-id identifies which query or
+** subquery the loop is part of.  The main query has a select-id of zero.
+** The select-id is the same value as is output in the first column
+** of an [EXPLAIN QUERY PLAN] query.
 ** </dl>
 */
 #define SQLITE_SCANSTAT_NLOOP    0
@@ -7466,6 +7473,7 @@ int sqlite3_vtab_on_conflict(sqlite3 *);
 #define SQLITE_SCANSTAT_EST      2
 #define SQLITE_SCANSTAT_NAME     3
 #define SQLITE_SCANSTAT_EXPLAIN  4
+#define SQLITE_SCANSTAT_SELECTID 5
 
 /*
 ** CAPI3REF: Prepared Statement Scan Status

src/vdbeInt.h

@@ -302,6 +302,7 @@ struct ScanStatus {
   int addrExplain;                /* OP_Explain for loop */
   int addrLoop;                   /* Address of "loops" counter */
   int addrVisit;                  /* Address of "rows visited" counter */
+  int iSelectID;                  /* The "Select-ID" for this loop */
   LogEst nEst;                    /* Estimated output rows per loop */
   char *zName;                    /* Name of table or index */
 };

src/vdbeapi.c

@@ -1521,6 +1521,14 @@ int sqlite3_stmt_scanstatus(
       }
       break;
     }
+    case SQLITE_SCANSTAT_SELECTID: {
+      if( pScan->addrExplain ){
+        *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;
+      }else{
+        *(int*)pOut = -1;
+      }
+      break;
+    }
     default: {
       return 1;
     }