SQLite

  if( pParse->nVar>0 ){
    sqlite3ErrorMsg(pParse, "parameters are not allowed in views");
    sqlite3SelectDelete(db, pSelect);
    return;
  }
  sqlite3StartTable(pParse, pName1, pName2, isTemp, 1, 0, noErr);
  p = pParse->pNewTable;
  if( p==0 || pParse->nErr ){
    sqlite3SelectDelete(db, pSelect);
    return;
  }


  sqlite3TwoPartName(pParse, pName1, pName2, &pName);
  iDb = sqlite3SchemaToIndex(db, p->pSchema);
  if( sqlite3FixInit(&sFix, pParse, iDb, "view", pName)
    && sqlite3FixSelect(&sFix, pSelect)
  ){
    sqlite3SelectDelete(db, pSelect);
    return;

  /*
  ** Pointers to the end of sqlite3GlobalConfig.pScratch and
  ** sqlite3GlobalConfig.pPage to a block of memory that records
  ** which pages are available.
  */
  u32 *aScratchFree;

  /*
  ** True if heap is nearly "full" where "full" is defined by the
  ** sqlite3_soft_heap_limit() setting.
  */
  int nearlyFull;
} mem0 = { 0, 0, 0, 0, 0, 0, 0, 0 };

#define mem0 GLOBAL(struct Mem0Global, mem0)

/*
** Initialize the memory allocation subsystem.
*/

                  [sqlite3GlobalConfig.szScratch*sqlite3GlobalConfig.nScratch];
    for(i=0; i<sqlite3GlobalConfig.nScratch; i++){ mem0.aScratchFree[i] = i; }
    mem0.nScratchFree = sqlite3GlobalConfig.nScratch;
  }else{
    sqlite3GlobalConfig.pScratch = 0;
    sqlite3GlobalConfig.szScratch = 0;
  }




  if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512
      || sqlite3GlobalConfig.nPage<1 ){

    sqlite3GlobalConfig.pPage = 0;





    sqlite3GlobalConfig.szPage = 0;
    sqlite3GlobalConfig.nPage = 0;
  }
  return sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData);
}

/*
** Return true if the heap is currently under memory pressure - in other
** words if the amount of heap used is close to the limit set by
** sqlite3_soft_heap_limit().
*/
int sqlite3HeapNearlyFull(void){
  return mem0.nearlyFull;
}

/*
** Deinitialize the memory allocation subsystem.
*/
void sqlite3MallocEnd(void){
  if( sqlite3GlobalConfig.m.xShutdown ){
    sqlite3GlobalConfig.m.xShutdown(sqlite3GlobalConfig.m.pAppData);

** Change the alarm callback
*/
int sqlite3MemoryAlarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  int nUsed;
  sqlite3_mutex_enter(mem0.mutex);
  mem0.alarmCallback = xCallback;
  mem0.alarmArg = pArg;
  mem0.alarmThreshold = iThreshold;
  nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
  mem0.nearlyFull = (iThreshold>0 && iThreshold<=nUsed);
  sqlite3_mutex_leave(mem0.mutex);
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_DEPRECATED
/*
** Deprecated external interface.  Internal/core SQLite code

  void *p;
  assert( sqlite3_mutex_held(mem0.mutex) );
  nFull = sqlite3GlobalConfig.m.xRoundup(n);
  sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n);
  if( mem0.alarmCallback!=0 ){
    int nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
    if( nUsed+nFull >= mem0.alarmThreshold ){
      mem0.nearlyFull = 1;
      sqlite3MallocAlarm(nFull);
    }else{
      mem0.nearlyFull = 0;
    }
  }
  p = sqlite3GlobalConfig.m.xMalloc(nFull);
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( p==0 && mem0.alarmCallback ){
    sqlite3MallocAlarm(nFull);
    p = sqlite3GlobalConfig.m.xMalloc(nFull);
  }
#endif
  if( p ){
    nFull = sqlite3MallocSize(p);
    sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nFull);
    sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, 1);
  }
  *pp = p;
  return nFull;

  int nMaxPage;                       /* Sum of nMaxPage for purgeable caches */
  int nMinPage;                       /* Sum of nMinPage for purgeable caches */
  int nCurrentPage;                   /* Number of purgeable pages allocated */
  PgHdr1 *pLruHead, *pLruTail;        /* LRU list of unpinned pages */

  /* Variables related to SQLITE_CONFIG_PAGECACHE settings. */
  int szSlot;                         /* Size of each free slot */
  int nSlot;                          /* The number of pcache slots */
  int nFreeSlot;                      /* Number of unused pcache slots */
  int nReserve;                       /* Try to keep nFreeSlot above this */
  void *pStart, *pEnd;                /* Bounds of pagecache malloc range */
  PgFreeslot *pFree;                  /* Free page blocks */
  int isInit;                         /* True if initialized */
} pcache1_g;

/*
** All code in this file should access the global structure above via the

** enough to contain 'n' buffers of 'sz' bytes each.
*/
void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
  if( pcache1.isInit ){
    PgFreeslot *p;
    sz = ROUNDDOWN8(sz);
    pcache1.szSlot = sz;
    pcache1.nSlot = pcache1.nFreeSlot = n;
    pcache1.nReserve = n>90 ? 10 : (n/10 + 1);
    pcache1.pStart = pBuf;
    pcache1.pFree = 0;
    while( n-- ){
      p = (PgFreeslot*)pBuf;
      p->pNext = pcache1.pFree;
      pcache1.pFree = p;
      pBuf = (void*)&((char*)pBuf)[sz];

  void *p;
  assert( sqlite3_mutex_held(pcache1.mutex) );
  sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
  if( nByte<=pcache1.szSlot && pcache1.pFree ){
    assert( pcache1.isInit );
    p = (PgHdr1 *)pcache1.pFree;
    pcache1.pFree = pcache1.pFree->pNext;
    pcache1.nFreeSlot--;
    assert( pcache1.nFreeSlot>=0 );
    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1);
  }else{

    /* Allocate a new buffer using sqlite3Malloc. Before doing so, exit the
    ** global pcache mutex and unlock the pager-cache object pCache. This is 
    ** so that if the attempt to allocate a new buffer causes the the 
    ** configured soft-heap-limit to be breached, it will be possible to

  if( p==0 ) return;
  if( p>=pcache1.pStart && p<pcache1.pEnd ){
    PgFreeslot *pSlot;
    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, -1);
    pSlot = (PgFreeslot*)p;
    pSlot->pNext = pcache1.pFree;
    pcache1.pFree = pSlot;
    pcache1.nFreeSlot++;
    assert( pcache1.nFreeSlot<=pcache1.nSlot );
  }else{
    int iSize;
    assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
    sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
    iSize = sqlite3MallocSize(p);
    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, -iSize);
    sqlite3_free(p);

*/
void sqlite3PageFree(void *p){
  pcache1EnterMutex();
  pcache1Free(p);
  pcache1LeaveMutex();
}


/*
** Return true if it desirable to avoid allocating a new page cache
** entry.
**
** If memory was allocated specifically to the page cache using
** SQLITE_CONFIG_PAGECACHE but that memory has all been used, then
** it is desirable to avoid allocating a new page cache entry because
** presumably SQLITE_CONFIG_PAGECACHE was suppose to be sufficient
** for all page cache needs and we should not need to spill the
** allocation onto the heap.
**
** Or, the heap is used for all page cache memory put the heap is
** under memory pressure, then again it is desirable to avoid
** allocating a new page cache entry in order to avoid stressing
** the heap even further.
*/
static int pcache1UnderMemoryPressure(PCache1 *pCache){
  assert( sqlite3_mutex_held(pcache1.mutex) );
  if( pcache1.nSlot && pCache->szPage<=pcache1.szSlot ){
    return pcache1.nFreeSlot<pcache1.nReserve;
  }else{
    return sqlite3HeapNearlyFull();
  }
}

/******************************************************************************/
/******** General Implementation Functions ************************************/

/*
** This function is used to resize the hash table used by the cache passed
** as the first argument.
**

**
**   1. Regardless of the value of createFlag, the cache is searched for a 
**      copy of the requested page. If one is found, it is returned.
**
**   2. If createFlag==0 and the page is not already in the cache, NULL is
**      returned.
**
**   3. If createFlag is 1, and the page is not already in the cache, then
**      return NULL (do not allocate a new page) if any of the following
**      conditions are true:
**
**       (a) the number of pages pinned by the cache is greater than
**           PCache1.nMax, or
**
**       (b) the number of pages pinned by the cache is greater than
**           the sum of nMax for all purgeable caches, less the sum of 
**           nMin for all other purgeable caches, or
**
**   4. If none of the first three conditions apply and the cache is marked
**      as purgeable, and if one of the following is true:
**
**       (a) The number of pages allocated for the cache is already 
**           PCache1.nMax, or
**
**       (b) The number of pages allocated for all purgeable caches is
**           already equal to or greater than the sum of nMax for all
**           purgeable caches,
**
**       (c) The system is under memory pressure and wants to avoid
**           unnecessary pages cache entry allocations
**
**      then attempt to recycle a page from the LRU list. If it is the right
**      size, return the recycled buffer. Otherwise, free the buffer and
**      proceed to step 5. 
**
**   5. Otherwise, allocate and return a new page buffer.
*/

  }

  /* Step 3 of header comment. */
  nPinned = pCache->nPage - pCache->nRecyclable;
  if( createFlag==1 && (
        nPinned>=(pcache1.nMaxPage+pCache->nMin-pcache1.nMinPage)
     || nPinned>=(pCache->nMax * 9 / 10)
     || pcache1UnderMemoryPressure(pCache)
  )){
    goto fetch_out;
  }

  if( pCache->nPage>=pCache->nHash && pcache1ResizeHash(pCache) ){
    goto fetch_out;
  }

  /* Step 4. Try to recycle a page buffer if appropriate. */
  if( pCache->bPurgeable && pcache1.pLruTail && (
         (pCache->nPage+1>=pCache->nMax)
      || pcache1.nCurrentPage>=pcache1.nMaxPage
      || pcache1UnderMemoryPressure(pCache)
  )){
    pPage = pcache1.pLruTail;
    pcache1RemoveFromHash(pPage);
    pcache1PinPage(pPage);
    if( pPage->pCache->szPage!=pCache->szPage ){
      pcache1FreePage(pPage);
      pPage = 0;

void *sqlite3ScratchMalloc(int);
void sqlite3ScratchFree(void*);
void *sqlite3PageMalloc(int);
void sqlite3PageFree(void*);
void sqlite3MemSetDefault(void);
void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
int sqlite3MemoryAlarm(void (*)(void*, sqlite3_int64, int), void*, sqlite3_int64);
int sqlite3HeapNearlyFull(void);

/*
** On systems with ample stack space and that support alloca(), make
** use of alloca() to obtain space for large automatic objects.  By default,
** obtain space from malloc().
**
** The alloca() routine never returns NULL.  This will cause code paths

sqlite3_config_pagecache [expr 1024+$xtra_size] 20
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-2 {PRAGMA page_size=1024}
#show_memstats
do_test memsubsys1-2.3 {
  set pg_ovfl [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]





} 0
do_test memsubsys1-2.4 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 20
do_test memsubsys1-2.5 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 0

# Test 3:  Activate PAGECACHE with 20 pages but use the wrong page size
# so that PAGECACHE is not used.
#

build_test_db memsubsys1-3.2 {PRAGMA page_size=2048}
#show_memstats
do_test memsubsys1-3.2.3 {
  db eval {PRAGMA page_size}
} 2048
do_test memsubsys1-3.2.4 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 20
do_test memsubsys1-3.2.5 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 0

# Test 4:  Activate both PAGECACHE and SCRATCH.
#
db close
sqlite3_shutdown
sqlite3_config_pagecache [expr 1024+$xtra_size] 50
sqlite3_config_scratch 6000 2
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-4 {PRAGMA page_size=1024}
#show_memstats
do_test memsubsys1-4.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
  expr {$pg_used>=45 && $pg_used<=50}
} 1
do_test memsubsys1-4.4 {
  set pg_ovfl [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]





} 0
do_test memsubsys1-4.5 {
  set maxreq [lindex [sqlite3_status SQLITE_STATUS_MALLOC_SIZE 0] 2]
  expr {$maxreq<7000}
} 1
do_test memsubsys1-4.6 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 1

sqlite3_config_scratch 6000 2
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-5 {PRAGMA page_size=4096}
#show_memstats
do_test memsubsys1-5.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 24
do_test memsubsys1-5.4 {
  set maxreq [lindex [sqlite3_status SQLITE_STATUS_MALLOC_SIZE 0] 2]
  expr {$maxreq>4096}
} 1
do_test memsubsys1-5.5 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 0

sqlite3_config_scratch 25300 1
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-6 {PRAGMA page_size=4096}
#show_memstats
do_test memsubsys1-6.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 24
#do_test memsubsys1-6.4 {
#  set maxreq [lindex [sqlite3_status SQLITE_STATUS_MALLOC_SIZE 0] 2]
#  expr {$maxreq>4096 && $maxreq<=(4096+$xtra_size)}
#} 1
do_test memsubsys1-6.5 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 1
do_test memsubsys1-6.6 {
  set s_ovfl [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_OVERFLOW 0] 2]
} 0