Refactor the SrcItem object to move fields associated with subqueries out

into a separate object named Subquery.  This reduces the size of the SrcItem
object by about 1/3rd and provides improved performance.

FossilOrigin-Name: 484bcd75bc95491d8540c791c1c4d40d996cb465839564662e14f98739699bf1

1 files changed, 11 insertions, 6 deletions

diff --git a/src/trigger.c b/src/trigger.c
index 98e8da58c..ff2df82cb 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -152,8 +152,10 @@ void sqlite3BeginTrigger(
   ** name on pTableName if we are reparsing out of the schema table
   */
   if( db->init.busy && iDb!=1 ){
-    sqlite3DbFree(db, pTableName->a[0].zDatabase);
-    pTableName->a[0].zDatabase = 0;
+    assert( pTableName->a[0].fg.fixedSchema==0 );
+    assert( pTableName->a[0].fg.isSubquery==0 );
+    sqlite3DbFree(db, pTableName->a[0].u4.zDatabase);
+    pTableName->a[0].u4.zDatabase = 0;
   }
 
   /* If the trigger name was unqualified, and the table is a temp table,
@@ -631,7 +633,8 @@ void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){
   }
 
   assert( pName->nSrc==1 );
-  zDb = pName->a[0].zDatabase;
+  assert( pName->a[0].fg.fixedSchema==0 && pName->a[0].fg.isSubquery==0 );
+  zDb = pName->a[0].u4.zDatabase;
   zName = pName->a[0].zName;
   assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
   for(i=OMIT_TEMPDB; i<db->nDb; i++){
@@ -868,7 +871,9 @@ SrcList *sqlite3TriggerStepSrc(
     Schema *pSchema = pStep->pTrig->pSchema;
     pSrc->a[0].zName = zName;
     if( pSchema!=db->aDb[1].pSchema ){
-      pSrc->a[0].pSchema = pSchema;
+      assert( pSrc->a[0].fg.fixedSchema || pSrc->a[0].u4.zDatabase==0 );
+      pSrc->a[0].u4.pSchema = pSchema;
+      pSrc->a[0].fg.fixedSchema = 1;
     }
     if( pStep->pFrom ){
       SrcList *pDup = sqlite3SrcListDup(db, pStep->pFrom, 0);
@@ -981,7 +986,7 @@ static int sqlite3ReturningSubqueryCorrelated(Walker *pWalker, Select *pSelect){
   pSrc = pSelect->pSrc;
   assert( pSrc!=0 );
   for(i=0; i<pSrc->nSrc; i++){
-    if( pSrc->a[i].pTab==pWalker->u.pTab ){
+    if( pSrc->a[i].pSTab==pWalker->u.pTab ){
       testcase( pSelect->selFlags & SF_Correlated );
       pSelect->selFlags |= SF_Correlated;
       pWalker->eCode = 1;
@@ -1052,7 +1057,7 @@ static void codeReturningTrigger(
   sSelect.pEList = sqlite3ExprListDup(db, pReturning->pReturnEL, 0);
   sSelect.pSrc = &sFrom;
   sFrom.nSrc = 1;
-  sFrom.a[0].pTab = pTab;
+  sFrom.a[0].pSTab = pTab;
   sFrom.a[0].zName = pTab->zName; /* tag-20240424-1 */
   sFrom.a[0].iCursor = -1;
   sqlite3SelectPrep(pParse, &sSelect, 0);