SQLite

** The maximum number of times that a statement will try to reparse
** itself before giving up and returning SQLITE_SCHEMA.
*/
#ifndef SQLITE_MAX_SCHEMA_RETRY
# define SQLITE_MAX_SCHEMA_RETRY 50
#endif

/*
** VDBE_DISPLAY_P4 is true or false depending on whether or not the
** "explain" P4 display logic is enabled.
*/
#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
# define VDBE_DISPLAY_P4 1
#else
# define VDBE_DISPLAY_P4 0
#endif

/*
** SQL is translated into a sequence of instructions to be
** executed by a virtual machine.  Each instruction is an instance
** of the following structure.
*/
typedef struct VdbeOp Op;

    zTemp[0] = 0;
    jj = 0;
  }
  return jj;
}
#endif /* SQLITE_DEBUG */

#if VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS)
/*
** Translate the P4.pExpr value for an OP_CursorHint opcode into text
** that can be displayed in the P4 column of EXPLAIN output.
*/
static int displayP4Expr(int nTemp, char *zTemp, Expr *pExpr){
  const char *zBinOp = 0;
  switch( pExpr->op ){
    case TK_STRING:
      sqlite3_snprintf(nTemp, zTemp, "%Q", pExpr->u.zToken);
      break;

    case TK_INTEGER:
      sqlite3_snprintf(nTemp, zTemp, "%d", pExpr->u.iValue);
      break;

    case TK_NULL:
      sqlite3_snprintf(nTemp, zTemp, "NULL");
      break;

    case TK_REGISTER: {
      sqlite3_snprintf(nTemp, zTemp, "r[%d]", pExpr->iTable);
      break;
    }

    case TK_COLUMN: {
      sqlite3_snprintf(nTemp, zTemp, "c%d", (int)pExpr->iColumn);
      break;
    }

    case TK_LT:      zBinOp = "<";        break;
    case TK_LE:      zBinOp = "<=";       break;
    case TK_GT:      zBinOp = ">";        break;
    case TK_GE:      zBinOp = ">=";       break;
    case TK_NE:      zBinOp = "!=";       break;
    case TK_EQ:      zBinOp = "==";       break;
    case TK_IS:      zBinOp = " IS ";     break;
    case TK_ISNOT:   zBinOp = " IS NOT "; break;
    case TK_AND:     zBinOp = " AND ";    break;
    case TK_OR:      zBinOp = " OR ";     break;
    case TK_PLUS:    zBinOp = "+";        break;
    case TK_STAR:    zBinOp = "*";        break;
    case TK_MINUS:   zBinOp = "-";        break;
    case TK_REM:     zBinOp = "%";        break;
    case TK_BITAND:  zBinOp = "&";        break;
    case TK_BITOR:   zBinOp = "|";        break;
    case TK_SLASH:   zBinOp = "/";        break;
    case TK_LSHIFT:  zBinOp = "<<";       break;
    case TK_RSHIFT:  zBinOp = ">>";       break;
    case TK_CONCAT:  zBinOp = "||";       break;

    default:
      sqlite3_snprintf(nTemp, zTemp, "%s", "expr");
      break;
  }

  if( zBinOp && nTemp>5 ){
    int n = 1;
    zTemp[0] = '(';
    n += displayP4Expr(nTemp-n, zTemp+n, pExpr->pLeft);
    sqlite3_snprintf(nTemp-n, zTemp+n, "%s", zBinOp);
    n += sqlite3Strlen30(zTemp+n);
    n += displayP4Expr(nTemp-n, zTemp+n, pExpr->pRight);
    sqlite3_snprintf(nTemp-n, zTemp+n, ")");
  }

  return sqlite3Strlen30(zTemp);
}
#endif /* VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS) */


#if VDBE_DISPLAY_P4
/*
** Compute a string that describes the P4 parameter for an opcode.
** Use zTemp for any required temporary buffer space.
*/
static char *displayP4(Op *pOp, char *zTemp, int nTemp){
  char *zP4 = zTemp;
  assert( nTemp>=20 );

      zTemp[i++] = ')';
      zTemp[i] = 0;
      assert( i<nTemp );
      break;
    }
#ifdef SQLITE_ENABLE_CURSOR_HINTS
    case P4_EXPR: {
      displayP4Expr(nTemp, zTemp, pOp->p4.pExpr);
      break;
    }
#endif
    case P4_COLLSEQ: {
      CollSeq *pColl = pOp->p4.pColl;
      sqlite3_snprintf(nTemp, zTemp, "(%.20s)", pColl->zName);
      break;

        zTemp[0] = 0;
      }
    }
  }
  assert( zP4!=0 );
  return zP4;
}
#endif /* VDBE_DISPLAY_P4 */

/*
** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
**
** The prepared statements need to know in advance the complete set of
** attached databases that will be use.  A mask of these databases
** is maintained in p->btreeMask.  The p->lockMask value is the subset of