Remove the aFKey hash table, which was not being used. Simplify the

FKey object.  Simplify the hash.c module since the copyKey parameter
formerly used only by aFKey is now no longer required. (CVS 6594)

FossilOrigin-Name: 80c43a355c6e482457abc2f9c3ad3a565cec55fb

manifest

@@ -1,5 +1,5 @@
-C Reduce\sthe\ssize\sof\san\sinteger\sliteral\sin\srowhash.tcl\sso\sthat\sthe\stest\nis\sable\sto\srun\swith\sthe\sdefault\sTCL\sinstallation\son\sMac\sOS\s10.5.\s(CVS\s6593)
+C Remove\sthe\saFKey\shash\stable,\swhich\swas\snot\sbeing\sused.\s\sSimplify\sthe\nFKey\sobject.\s\sSimplify\sthe\shash.c\smodule\ssince\sthe\scopyKey\sparameter\nformerly\sused\sonly\sby\saFKey\sis\snow\sno\slonger\srequired.\s(CVS\s6594)
-D 2009-05-02T12:02:02
+D 2009-05-02T13:29:38
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 583e87706abc3026960ed759aff6371faf84c211
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -109,8 +109,8 @@ F src/btmutex.c 9b899c0d8df3bd68f527b0afe03088321b696d3c
 F src/btree.c 64ad8841aefce2ba0cb3b138e5fe8669ce5fa6db
 F src/btree.h 99fcc7e8c4a1e35afe271bcb38de1a698dfc904e
 F src/btreeInt.h df64030d632f8c8ac217ed52e8b6b3eacacb33a5
-F src/build.c a079f965feea2d0b469b293e09cd0ac41be1272f
+F src/build.c 9f00cc9cc0a3e7271dad30cd11915ea1f323174d
-F src/callback.c 73016376d6848ba987709e8c9048d4f0e0776036
+F src/callback.c 3aff18ce7ede2baba7c7cad1f55f9d88fa0c323e
 F src/complete.c 5ad5c6cd4548211867c204c41a126d73a9fbcea0
 F src/date.c d327ec7bb2f64b08d32b1035de82b9ba8675de91
 F src/delete.c a0a0932eea77471ab243337026abbce444024c43
@@ -118,14 +118,14 @@ F src/expr.c 40b35167137c53777d15d3247d93615b4eefec2d
 F src/fault.c dc88c821842157460750d2d61a8a8b4197d047ff
 F src/func.c f667fe886309707c7178542073bb0ced00a9fae7
 F src/global.c 448419c44ce0701104c2121b0e06919b44514c0c
-F src/hash.c 0caea57f020226903cd8591125732e1e19f17f14
+F src/hash.c 7e90268f62662dc8ccb9da1e93090ea64481e4f8
-F src/hash.h 457e230c3b2bd3c56742824d43b16618ff30d7c0
+F src/hash.h 35b216c13343d0b4f87d9f21969ac55ad72174e1
 F src/hwtime.h 4a1d45f4cae1f402ea19686acf24acf4f0cb53cb
 F src/insert.c 0805018acaa97c5f5b83d4e058da821bc12fa0c6
 F src/journal.c e00df0c0da8413ab6e1bb7d7cab5665d4a9000d0
 F src/legacy.c 2ad5b52df322d0f132f66817095e0e79c8942611
 F src/loadext.c 3f96631089fc4f3871a67f02f2e4fc7ea4d51edc
-F src/main.c 96da66bcc2639d9ed3b0d223853ba79e34da7025
+F src/main.c 27a22ea98931594fcd476c87066a948a2faa53b6
 F src/malloc.c a1f0f8ae110abb8eb546e259ab0eaea7e0f9b588
 F src/mem0.c f2f84062d1f35814d6535c9f9e33de3bfb3b132c
 F src/mem1.c e6d5c23941288df8191b8a98c28e3f57771e2270
@@ -162,7 +162,7 @@ F src/select.c 84022ec5d41c321e98fa96e4f4d5e44de203a099
 F src/shell.c 0a11f831603f17fea20ca97133c0f64e716af4a7
 F src/sqlite.h.in 926985a312747e284c21ab32a8e8231a3bed9bd1
 F src/sqlite3ext.h 1db7d63ab5de4b3e6b83dd03d1a4e64fef6d2a17
-F src/sqliteInt.h 6ca6e40ee904ccdbbaaa3da82c0c92057459cf75
+F src/sqliteInt.h a734ac9d1c5f0d2b3b1ebc8581e237d1293ae6b7
 F src/sqliteLimit.h ffe93f5a0c4e7bd13e70cd7bf84cfb5c3465f45d
 F src/status.c 237b193efae0cf6ac3f0817a208de6c6c6ef6d76
 F src/table.c cc86ad3d6ad54df7c63a3e807b5783c90411a08d
@@ -727,7 +727,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 9950c0a79c82eb7d8495b0b1a8fe117d566e2387
+P 2229accef308db9feac4e1de16b57e7f680dbb1a
-R 6ae38c3439a7c80d21c4c447ba2af531
+R 7adc2aa8ad28fd5fae72c98955166e30
 U drh
-Z a3a56a3572a73362a5dc6024fff3a217
+Z de5878a9bc4d8c7d1245568e36e5b246

manifest.uuid

@@ -1 +1 @@
-2229accef308db9feac4e1de16b57e7f680dbb1a
+80c43a355c6e482457abc2f9c3ad3a565cec55fb

src/build.c

@@ -22,7 +22,7 @@
 **     COMMIT
 **     ROLLBACK
 **
-** $Id: build.c,v 1.533 2009/05/01 21:13:37 drh Exp $
+** $Id: build.c,v 1.534 2009/05/02 13:29:38 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -489,8 +489,7 @@ static void sqliteResetColumnNames(Table *pTable){
 ** Table.  No changes are made to disk by this routine.
 **
 ** This routine just deletes the data structure.  It does not unlink
-** the table data structure from the hash table.  Nor does it remove
+** the table data structure from the hash table.  But it does destroy
-** foreign keys from the sqlite.aFKey hash table.  But it does destroy
 ** memory structures of the indices and foreign keys associated with 
 ** the table.
 */
@@ -518,13 +517,9 @@ void sqlite3DeleteTable(Table *pTable){
   }
 
 #ifndef SQLITE_OMIT_FOREIGN_KEY
-  /* Delete all foreign keys associated with this table.  The keys
+  /* Delete all foreign keys associated with this table. */
-  ** should have already been unlinked from the pSchema->aFKey hash table 
-  */
   for(pFKey=pTable->pFKey; pFKey; pFKey=pNextFKey){
     pNextFKey = pFKey->pNextFrom;
-    assert( sqlite3HashFind(&pTable->pSchema->aFKey,
-                           pFKey->zTo, sqlite3Strlen30(pFKey->zTo))!=pFKey );
     sqlite3DbFree(db, pFKey);
   }
 #endif
@@ -548,7 +543,6 @@ void sqlite3DeleteTable(Table *pTable){
 */
 void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
   Table *p;
-  FKey *pF1, *pF2;
   Db *pDb;
 
   assert( db!=0 );
@@ -557,23 +551,7 @@ void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
   pDb = &db->aDb[iDb];
   p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName,
                         sqlite3Strlen30(zTabName),0);
-  if( p ){
-#ifndef SQLITE_OMIT_FOREIGN_KEY
-    for(pF1=p->pFKey; pF1; pF1=pF1->pNextFrom){
-      int nTo = sqlite3Strlen30(pF1->zTo);
-      pF2 = sqlite3HashFind(&pDb->pSchema->aFKey, pF1->zTo, nTo);
-      if( pF2==pF1 ){
-        sqlite3HashInsert(&pDb->pSchema->aFKey, pF1->zTo, nTo, pF1->pNextTo);
-      }else{
-        while( pF2 && pF2->pNextTo!=pF1 ){ pF2=pF2->pNextTo; }
-        if( pF2 ){
-          pF2->pNextTo = pF1->pNextTo;
-        }
-      }
-    }
-#endif
   sqlite3DeleteTable(p);
-  }
   db->flags |= SQLITE_InternChanges;
 }
 
@@ -1688,7 +1666,6 @@ void sqlite3EndTable(
   */
   if( db->init.busy && pParse->nErr==0 ){
     Table *pOld;
-    FKey *pFKey; 
     Schema *pSchema = p->pSchema;
     pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName,
                              sqlite3Strlen30(p->zName),p);
@@ -1697,17 +1674,6 @@ void sqlite3EndTable(
       db->mallocFailed = 1;
       return;
     }
-#ifndef SQLITE_OMIT_FOREIGN_KEY
-    for(pFKey=p->pFKey; pFKey; pFKey=pFKey->pNextFrom){
-      void *data;
-      int nTo = sqlite3Strlen30(pFKey->zTo);
-      pFKey->pNextTo = sqlite3HashFind(&pSchema->aFKey, pFKey->zTo, nTo);
-      data = sqlite3HashInsert(&pSchema->aFKey, pFKey->zTo, nTo, pFKey);
-      if( data==(void *)pFKey ){
-        db->mallocFailed = 1;
-      }
-    }
-#endif
     pParse->pNewTable = 0;
     db->nTable++;
     db->flags |= SQLITE_InternChanges;
@@ -2214,9 +2180,7 @@ exit_drop_table:
 ** in the ON DELETE, ON UPDATE and ON INSERT clauses.
 **
 ** An FKey structure is created and added to the table currently
-** under construction in the pParse->pNewTable field.  The new FKey
+** under construction in the pParse->pNewTable field.
-** is not linked into db->aFKey at this point - that does not happen
-** until sqlite3EndTable().
 **
 ** The foreign key is set for IMMEDIATE processing.  A subsequent call
 ** to sqlite3DeferForeignKey() might change this to DEFERRED.
@@ -2257,7 +2221,7 @@ void sqlite3CreateForeignKey(
   }else{
     nCol = pFromCol->nExpr;
   }
-  nByte = sizeof(*pFKey) + nCol*sizeof(pFKey->aCol[0]) + pTo->n + 1;
+  nByte = sizeof(*pFKey) + (nCol-1)*sizeof(pFKey->aCol[0]) + pTo->n + 1;
   if( pToCol ){
     for(i=0; i<pToCol->nExpr; i++){
       nByte += sqlite3Strlen30(pToCol->a[i].zName) + 1;
@@ -2269,15 +2233,12 @@ void sqlite3CreateForeignKey(
   }
   pFKey->pFrom = p;
   pFKey->pNextFrom = p->pFKey;
-  z = (char*)&pFKey[1];
+  z = (char*)&pFKey->aCol[nCol];
-  pFKey->aCol = (struct sColMap*)z;
-  z += sizeof(struct sColMap)*nCol;
   pFKey->zTo = z;
   memcpy(z, pTo->z, pTo->n);
   z[pTo->n] = 0;
   sqlite3Dequote(z);
   z += pTo->n+1;
-  pFKey->pNextTo = 0;
   pFKey->nCol = nCol;
   if( pFromCol==0 ){
     pFKey->aCol[0].iFrom = p->nCol-1;

src/callback.c

@@ -13,7 +13,7 @@
 ** This file contains functions used to access the internal hash tables
 ** of user defined functions and collation sequences.
 **
-** $Id: callback.c,v 1.37 2009/03/24 15:08:10 drh Exp $
+** $Id: callback.c,v 1.38 2009/05/02 13:29:38 drh Exp $
 */
 
 #include "sqliteInt.h"
@@ -413,14 +413,13 @@ void sqlite3SchemaFree(void *p){
 
   temp1 = pSchema->tblHash;
   temp2 = pSchema->trigHash;
-  sqlite3HashInit(&pSchema->trigHash, 0);
+  sqlite3HashInit(&pSchema->trigHash);
-  sqlite3HashClear(&pSchema->aFKey);
   sqlite3HashClear(&pSchema->idxHash);
   for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
     sqlite3DeleteTrigger(0, (Trigger*)sqliteHashData(pElem));
   }
   sqlite3HashClear(&temp2);
-  sqlite3HashInit(&pSchema->tblHash, 0);
+  sqlite3HashInit(&pSchema->tblHash);
   for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
     Table *pTab = sqliteHashData(pElem);
     assert( pTab->dbMem==0 );
@@ -445,10 +444,9 @@ Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
   if( !p ){
     db->mallocFailed = 1;
   }else if ( 0==p->file_format ){
-    sqlite3HashInit(&p->tblHash, 0);
+    sqlite3HashInit(&p->tblHash);
-    sqlite3HashInit(&p->idxHash, 0);
+    sqlite3HashInit(&p->idxHash);
-    sqlite3HashInit(&p->trigHash, 0);
+    sqlite3HashInit(&p->trigHash);
-    sqlite3HashInit(&p->aFKey, 1);
     p->enc = SQLITE_UTF8;
   }
   return p;

src/hash.c

@@ -12,7 +12,7 @@
 ** This is the implementation of generic hash-tables
 ** used in SQLite.
 **
-** $Id: hash.c,v 1.36 2009/04/28 17:33:16 drh Exp $
+** $Id: hash.c,v 1.37 2009/05/02 13:29:38 drh Exp $
 */
 #include "sqliteInt.h"
 #include <assert.h>
@@ -21,12 +21,9 @@
 ** fields of the Hash structure.
 **
 ** "pNew" is a pointer to the hash table that is to be initialized.
-** "copyKey" is true if the hash table should make its own private
-** copy of keys and false if it should just use the supplied pointer.
 */
-void sqlite3HashInit(Hash *pNew, int copyKey){
+void sqlite3HashInit(Hash *pNew){
   assert( pNew!=0 );
-  pNew->copyKey = copyKey!=0;
   pNew->first = 0;
   pNew->count = 0;
   pNew->htsize = 0;
@@ -48,9 +45,6 @@ void sqlite3HashClear(Hash *pH){
   pH->htsize = 0;
   while( elem ){
     HashElem *next_elem = elem->next;
-    if( pH->copyKey ){
-      sqlite3_free(elem->pKey);
-    }
     sqlite3_free(elem);
     elem = next_elem;
   }
@@ -58,10 +52,9 @@ void sqlite3HashClear(Hash *pH){
 }
 
 /*
-** Hash and comparison functions when the mode is SQLITE_HASH_STRING
+** The hashing function.
 */
-static unsigned int strHash(const void *pKey, int nKey){
+static unsigned int strHash(const char *z, int nKey){
-  const char *z = (const char *)pKey;
   int h = 0;
   assert( nKey>=0 );
   while( nKey > 0  ){
@@ -70,10 +63,6 @@ static unsigned int strHash(const void *pKey, int nKey){
   }
   return h;
 }
-static int strCompare(const void *pKey1, int n1, const void *pKey2, int n2){
-  if( n1!=n2 ) return 1;
-  return sqlite3StrNICmp((const char*)pKey1,(const char*)pKey2,n1);
-}
 
 
 /* Link pNew element into the hash table pH.  If pEntry!=0 then also
@@ -151,7 +140,7 @@ static int rehash(Hash *pH, unsigned int new_size){
 */
 static HashElem *findElementGivenHash(
   const Hash *pH,     /* The pH to be searched */
-  const void *pKey,   /* The key we are searching for */
+  const char *pKey,   /* The key we are searching for */
   int nKey,           /* Bytes in key (not counting zero terminator) */
   unsigned int h      /* The hash for this key. */
 ){
@@ -167,7 +156,7 @@ static HashElem *findElementGivenHash(
     count = pH->count;
   }
   while( count-- && ALWAYS(elem) ){
-    if( strCompare(elem->pKey,elem->nKey,pKey,nKey)==0 ){ 
+    if( elem->nKey==nKey && sqlite3StrNICmp(elem->pKey,pKey,nKey)==0 ){ 
       return elem;
     }
     elem = elem->next;
@@ -200,9 +189,6 @@ static void removeElementGivenHash(
     pEntry->count--;
     assert( pEntry->count>=0 );
   }
-  if( pH->copyKey ){
-    sqlite3_free(elem->pKey);
-  }
   sqlite3_free( elem );
   pH->count--;
   if( pH->count<=0 ){
@@ -216,7 +202,7 @@ static void removeElementGivenHash(
 ** that matches pKey,nKey.  Return the data for this element if it is
 ** found, or NULL if there is no match.
 */
-void *sqlite3HashFind(const Hash *pH, const void *pKey, int nKey){
+void *sqlite3HashFind(const Hash *pH, const char *pKey, int nKey){
   HashElem *elem;    /* The element that matches key */
   unsigned int h;    /* A hash on key */
 
@@ -236,8 +222,7 @@ void *sqlite3HashFind(const Hash *pH, const void *pKey, int nKey){
 ** and the data is "data".
 **
 ** If no element exists with a matching key, then a new
-** element is created.  A copy of the key is made if the copyKey
+** element is created and NULL is returned.
-** flag is set.  NULL is returned.
 **
 ** If another element already exists with the same key, then the
 ** new data replaces the old data and the old data is returned.
@@ -247,7 +232,7 @@ void *sqlite3HashFind(const Hash *pH, const void *pKey, int nKey){
 ** If the "data" parameter to this function is NULL, then the
 ** element corresponding to "key" is removed from the hash table.
 */
-void *sqlite3HashInsert(Hash *pH, const void *pKey, int nKey, void *data){
+void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, void *data){
   unsigned int h;       /* the hash of the key modulo hash table size */
   HashElem *elem;       /* Used to loop thru the element list */
   HashElem *new_elem;   /* New element added to the pH */
@@ -267,9 +252,7 @@ void *sqlite3HashInsert(Hash *pH, const void *pKey, int nKey, void *data){
       removeElementGivenHash(pH,elem,h);
     }else{
       elem->data = data;
-      if( !pH->copyKey ){
+      elem->pKey = pKey;
-        elem->pKey = (void *)pKey;
-      }
       assert(nKey==elem->nKey);
     }
     return old_data;
@@ -277,16 +260,7 @@ void *sqlite3HashInsert(Hash *pH, const void *pKey, int nKey, void *data){
   if( data==0 ) return 0;
   new_elem = (HashElem*)sqlite3Malloc( sizeof(HashElem) );
   if( new_elem==0 ) return data;
-  if( pH->copyKey ){
+  new_elem->pKey = pKey;
-    new_elem->pKey = sqlite3Malloc( nKey );
-    if( new_elem->pKey==0 ){
-      sqlite3_free(new_elem);
-      return data;
-    }
-    memcpy((void*)new_elem->pKey, pKey, nKey);
-  }else{
-    new_elem->pKey = (void*)pKey;
-  }
   new_elem->nKey = nKey;
   new_elem->data = data;
   pH->count++;

src/hash.h

@@ -12,7 +12,7 @@
 ** This is the header file for the generic hash-table implemenation
 ** used in SQLite.
 **
-** $Id: hash.h,v 1.14 2009/04/28 16:35:43 drh Exp $
+** $Id: hash.h,v 1.15 2009/05/02 13:29:38 drh Exp $
 */
 #ifndef _SQLITE_HASH_H_
 #define _SQLITE_HASH_H_
@@ -43,8 +43,7 @@ typedef struct HashElem HashElem;
 ** the hash table.
 */
 struct Hash {
-  unsigned int copyKey : 1; /* True if copy of key made on insert */
+  unsigned int htsize;      /* Number of buckets in the hash table */
-  unsigned int htsize : 31; /* Number of buckets in the hash table */
   unsigned int count;       /* Number of entries in this table */
   HashElem *first;          /* The first element of the array */
   struct _ht {              /* the hash table */
@@ -62,15 +61,15 @@ struct Hash {
 struct HashElem {
   HashElem *next, *prev;       /* Next and previous elements in the table */
   void *data;                  /* Data associated with this element */
-  void *pKey; int nKey;    /* Key associated with this element */
+  const char *pKey; int nKey;  /* Key associated with this element */
 };
 
 /*
 ** Access routines.  To delete, insert a NULL pointer.
 */
-void sqlite3HashInit(Hash*, int copyKey);
+void sqlite3HashInit(Hash*);
-void *sqlite3HashInsert(Hash*, const void *pKey, int nKey, void *pData);
+void *sqlite3HashInsert(Hash*, const char *pKey, int nKey, void *pData);
-void *sqlite3HashFind(const Hash*, const void *pKey, int nKey);
+void *sqlite3HashFind(const Hash*, const char *pKey, int nKey);
 void sqlite3HashClear(Hash*);
 
 /*

src/main.c

@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: main.c,v 1.544 2009/04/30 12:25:10 drh Exp $
+** $Id: main.c,v 1.545 2009/05/02 13:29:38 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -1580,9 +1580,9 @@ static int openDatabase(
                  | SQLITE_LoadExtension
 #endif
       ;
-  sqlite3HashInit(&db->aCollSeq, 0);
+  sqlite3HashInit(&db->aCollSeq);
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  sqlite3HashInit(&db->aModule, 0);
+  sqlite3HashInit(&db->aModule);
 #endif
 
   db->pVfs = sqlite3_vfs_find(zVfs);

src/sqliteInt.h

@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.865 2009/05/01 21:13:37 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.866 2009/05/02 13:29:38 drh Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -639,7 +639,6 @@ struct Schema {
   Hash tblHash;        /* All tables indexed by name */
   Hash idxHash;        /* All (named) indices indexed by name */
   Hash trigHash;       /* All triggers indexed by name */
-  Hash aFKey;          /* Foreign keys indexed by to-table */
   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
   u8 file_format;      /* Schema format version for this file */
   u8 enc;              /* Text encoding used by this database */
@@ -1195,28 +1194,21 @@ struct Table {
 **
 ** Each REFERENCES clause generates an instance of the following structure
 ** which is attached to the from-table.  The to-table need not exist when
-** the from-table is created.  The existence of the to-table is not checked
+** the from-table is created.  The existence of the to-table is not checked.
-** until an attempt is made to insert data into the from-table.
-**
-** The sqlite.aFKey hash table stores pointers to this structure
-** given the name of a to-table.  For each to-table, all foreign keys
-** associated with that table are on a linked list using the FKey.pNextTo
-** field.
 */
 struct FKey {
   Table *pFrom;     /* The table that contains the REFERENCES clause */
   FKey *pNextFrom;  /* Next foreign key in pFrom */
   char *zTo;        /* Name of table that the key points to */
-  FKey *pNextTo;    /* Next foreign key that points to zTo */
   int nCol;         /* Number of columns in this key */
-  struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
-    int iFrom;         /* Index of column in pFrom */
-    char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
-  } *aCol;          /* One entry for each of nCol column s */
   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
   u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
   u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
   u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
+  struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
+    int iFrom;         /* Index of column in pFrom */
+    char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
+  } aCol[1];        /* One entry for each of nCol column s */
 };
 
 /*