Improvements to EXPLAIN QUERY PLAN output for multi-row VALUES claues.

FossilOrigin-Name: ac6f095e13e43d66c06552c8b01f6bec3407c9d41a34c4cdb0be57b0b828ad0d

4 files changed, 13 insertions, 1 deletions

diff --git a/src/insert.c b/src/insert.c
index 7d386f5d2..7256281fd 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -721,6 +721,7 @@ Select *sqlite3MultiValues(Parse *pParse, Select *pLeft, ExprList *pRow){
         p->addrFillSub = sqlite3VdbeCurrentAddr(v) + 1;
         p->regReturn = ++pParse->nMem;
         p->iCursor = -1;
+        p->u1.nRow = 2;
         sqlite3VdbeAddOp3(v,OP_InitCoroutine,p->regReturn,0,p->addrFillSub);
         sqlite3SelectDestInit(&dest, SRT_Coroutine, p->regReturn);
 
@@ -733,6 +734,7 @@ Select *sqlite3MultiValues(Parse *pParse, Select *pLeft, ExprList *pRow){
         dest.nSdst = pLeft->pEList->nExpr;
         pParse->nMem += 2 + dest.nSdst;
 
+        pLeft->selFlags |= SF_MultiValue;
         sqlite3Select(pParse, pLeft, &dest);
         p->regResult = dest.iSdst;
         assert( pParse->nErr || dest.iSdst>0 );
@@ -740,6 +742,7 @@ Select *sqlite3MultiValues(Parse *pParse, Select *pLeft, ExprList *pRow){
       }
     }else{
       p = &pLeft->pSrc->a[0];
+      p->u1.nRow++;
     }
   
     if( pParse->nErr==0 ){
@@ -1102,6 +1105,7 @@ void sqlite3Insert(
       dest.iSDParm = regYield = pItem->regReturn;
       regFromSelect = pItem->regResult;
       nColumn = pItem->pSelect->pEList->nExpr;
+      ExplainQueryPlan((pParse, 0, "SCAN %S", pItem));
       if( bIdListInOrder && nColumn==pTab->nCol ){
         regData = regFromSelect;
         regRowid = regData - 1;
diff --git a/src/printf.c b/src/printf.c
index 186e95bb8..0aea74e89 100644
--- a/src/printf.c
+++ b/src/printf.c
@@ -860,6 +860,9 @@ void sqlite3_str_vappendf(
           assert( pSel!=0 );
           if( pSel->selFlags & SF_NestedFrom ){
             sqlite3_str_appendf(pAccum, "(join-%u)", pSel->selId);
+          }else if( pSel->selFlags & SF_MultiValue ){
+            sqlite3_str_appendf(pAccum, "%u-ROW VALUES CLAUSE",
+                                pItem->u1.nRow);
           }else{
             sqlite3_str_appendf(pAccum, "(subquery-%u)", pSel->selId);
           }
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 54fe9458f..01a512649 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3311,6 +3311,7 @@ struct SrcItem {
   union {
     char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */
     ExprList *pFuncArg;  /* Arguments to table-valued-function */
+    u32 nRow;            /* Number of rows in a VALUES clause */
   } u1;
   union {
     Index *pIBIndex;  /* Index structure corresponding to u1.zIndexedBy */
diff --git a/src/where.c b/src/where.c
index 2a99c7398..2463e823c 100644
--- a/src/where.c
+++ b/src/where.c
@@ -6144,7 +6144,11 @@ WhereInfo *sqlite3WhereBegin(
     ){
       pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
     }
-    ExplainQueryPlan((pParse, 0, "SCAN CONSTANT ROW"));
+    if( ALWAYS(pWInfo->pSelect)
+     && (pWInfo->pSelect->selFlags & SF_MultiValue)==0
+    ){
+      ExplainQueryPlan((pParse, 0, "SCAN CONSTANT ROW"));
+    }
   }else{
     /* Assign a bit from the bitmask to every term in the FROM clause.
     **