2442   u8 nReserve;                   /* Byte of unused space on each page */  in sqlite3BtreeOpen()  local
2618       nReserve = 0;  in sqlite3BtreeOpen()
2623       nReserve = zDbHeader[20];  in sqlite3BtreeOpen()
2630     rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize, nReserve);  in sqlite3BtreeOpen()
2632     pBt->usableSize = pBt->pageSize - nReserve;  in sqlite3BtreeOpen()
2967 int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){  in sqlite3BtreeSetPageSize()  argument
2971   assert( nReserve>=0 && nReserve<=255 );  in sqlite3BtreeSetPageSize()
2973   pBt->nReserveWanted = nReserve;  in sqlite3BtreeSetPageSize()
2975   if( nReserve<x ) nReserve = x;  in sqlite3BtreeSetPageSize()
2980   assert( nReserve>=0 && nReserve<=255 );  in sqlite3BtreeSetPageSize()
2985     if( nReserve>32 && pageSize==512 ) pageSize = 1024;  in sqlite3BtreeSetPageSize()
2989   rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize, nReserve);  in sqlite3BtreeSetPageSize()
2990   pBt->usableSize = pBt->pageSize - (u16)nReserve;  in sqlite3BtreeSetPageSize()