OracleSession.Pool:= OracleSessionPool;
OracleSession.LogOn; 
OracleQuery.Session:= OracleSession;
OracleQuery.Execute;
OracleQuery.Close;
OracleQuery.Session:= nil;
OracleSession.LogOff;

OracleQuery.SetVariable;
OracleSession.Pool:= OracleSessionPool;
OracleSession.LogOn; 
OracleQuery.Session:= OracleSession;
OracleQuery.Execute;
OracleQuery.Close;
OracleQuery.Session:= nil;
OracleSession.LogOff;

OracleSession.Pool:= OracleSessionPool;
OracleSession.LogOn; 
OracleQuery.Session:= OracleSession;
OracleQuery.SetVariable;
OracleQuery.Execute;
OracleQuery.Close;
OracleQuery.Session:= nil;
OracleSession.LogOff;

procedure TOracleSession.GetEnv;
var EnvMode: ub4;
begin
  if UseSingleEnvironment then
    envhp := GetSingleEnv
  else begin
    EnvMode := OCI_DEFAULT;
    if not OCI81 then
    begin
      if not ThreadSafe then EnvMode := EnvMode or OCI_ENV_NO_MUTEX;
      OCICall(OCIEnvInit(envhp, EnvMode, 0, nil))
    end else begin
      // Net8 8.1 cannot switch ctx to lda in no_mutex mode
      EnvMode := EnvMode or OCI_OBJECT;
      if ThreadSafe then  EnvMode := EnvMode or OCI_THREADED;
      if not ThreadSafe then EnvMode := EnvMode or OCI_ENV_NO_MUTEX;
      OCICall(OCIEnvCreate(envhp, EnvMode, nil, nil, nil, nil, 0, nil));
     
    end;
  end;
end;

// Parse the SQL text of a Query
procedure TOracleQuery.Parse(Deferred: Boolean);
var s, sc: AnsiString;
    ss: String;
    i, j, PreFetch: Integer;
    ft: ub2;
    defflg: sword;
    VarData: TVariableData;
begin
  FErrorPosition := 0;
  FErrorLine := 0;
  Open;
  if ResultSet then
  begin
    FFunctionType := ftSelect;
    Described := False;
    Session.FLastSQL := '';
    Exit;
  end;
  ss := FSQL.Text;
  // Replace substitution variables by the actual values
  ReplaceSubstVariables(ss);
  {$IFDEF CompilerVersion2009}
  if UTF8Client then
    sc := UTF8Encode(ss)
  else
    sc := AnsiString(ss);
  {$ELSE}
    sc := ss;
  {$ENDIF}
  // Strip cr's from the SQL text
  SetLength(s, Length(sc));
  j := 0;
  for i := 1 to Length(sc) do
  begin
    if sc[i] <> #13 then
    begin
      Inc(j);
      s[j] := sc[i];
    end;
  end;
  SetLength(s, j);
  if s = '' then s := ' ';
  // Because of a bug in Net8, we need to reparse when a long, long raw or array variable is used
  if Session.UseOCI80 then
  begin
    for i := 0 to Variables.Count - 1 do
    begin
      VarData := Variables.Data(i);
      if (VarData.BufType in [otLong, otLongRaw]) or
         (VarData.IsPLSQLTable) or
         (VarData.ArraySize > 1) or
         (ArrayBindSize > 1) then ParsedSQL := '';
    end;
  end;
  // Parse only if SQL text has changed since the last parse
  // and function does not need to be parsed
  if (not Optimize) or (ParsedSQL = '') or (ParsedSQL <> s) or not
     (FFunctionType in [3, 4, 5, 9, 33, 34, 35, 54, 55, 56]) then
  begin
    FieldList.Clear;
    ParsedSQL := s;
    Session.Acquire(True);
    FFunctionType := 0;
    if Session.UseOCI80 then
    begin
      AllocStmthp;
      if Session.AreStatementsCached then
        OCICall(OCIStmtPrepare2(Session.svchp, stmthp, errhp, PAnsiChar(ParsedSQL), length(ParsedSQL), nil, 0, OCI_NTV_SYNTAX, OCI_DEFAULT))
      else
        OCICall(OCIStmtPrepare(stmthp, errhp, PAnsiChar(ParsedSQL), length(ParsedSQL), OCI_NTV_SYNTAX, OCI_DEFAULT));
      if GetReturnCode = 0 then
      begin
        // No Oracle8 caching
        PreFetch := 0;
        OCICall(OCIAttrSet(stmthp, OCI_HTYPE_STMT, @PreFetch, SizeOf(Pointer), OCI_ATTR_PREFETCH_ROWS, errhp));
        OCICall(OCIAttrSet(stmthp, OCI_HTYPE_STMT, @PreFetch, SizeOf(Pointer), OCI_ATTR_PREFETCH_MEMORY, errhp));
        OCICall(OCIAttrGet(stmthp, OCI_HTYPE_STMT, ft, nil, OCI_ATTR_STMT_TYPE, errhp));
        case ft of
          OCI_STMT_SELECT: FFunctionType := 4;
          OCI_STMT_UPDATE: FFunctionType := 5;
          OCI_STMT_DELETE: FFunctionType := 9;
          OCI_STMT_INSERT: FFunctionType := 3;
           OCI_STMT_BEGIN: FFunctionType := 34;
         OCI_STMT_DECLARE: FFunctionType := 34;
        else
          FFunctionType := -1;
        end;
      end;
    end else begin
      if Deferred then defflg := 1 else defflg := 0;
      oparse(CDA, PAnsiChar(ParsedSQL), -1, defflg, 2);
      // Parsed successfully, set functiontype
      FFunctionType := CDA.ft;
    end;
    if GetReturnCode <> 0 then
    begin
      ParsedSQL := '';
      RaiseException;
    end;
    Session.Release(True);
    // If parsed then the Query must be described as well
    Described := False;
  end;
end;

{$IF not defined(X86ASMRTL)}
function _UStrClr(var S): Pointer;
var
  P: PStrRec;
begin
  if Pointer(S) <> nil then
  begin
    P := Pointer(PByte(S) - SizeOf(StrRec));
    Pointer(S) := nil;
    if P.refCnt > 0 then
    begin
      if AtomicDecrement(P.refCnt) = 0 then
        FreeMem(P);
    end;
  end;
  Result := @S;
end;
{$ELSE X86ASMRTL}
procedure _UStrClr(var S);
{$IFDEF CPUX86}
asm
        { ->    EAX     pointer to str  }
        { <-    EAX     pointer to str  }

        MOV     EDX,[EAX]                       { fetch str                     }
        TEST    EDX,EDX                         { if nil, nothing to do         }
        JE      @@done
        MOV     dword ptr [EAX],0               { clear str                     }
        MOV     ECX,[EDX-skew].StrRec.refCnt    { fetch refCnt                  }
        DEC     ECX                             { if < 0: literal str           }
        JL      @@done
   LOCK DEC     [EDX-skew].StrRec.refCnt        { threadsafe dec refCount       }
        JNE     @@done
        {$IFDEF ALIGN_STACK}
        SUB     ESP,8
        {$ENDIF ALIGN_STACK}
        PUSH    EAX
        LEA     EAX,[EDX-skew]                  { if refCnt now zero, deallocate}
        CALL    _FreeMem
        POP     EAX
        {$IFDEF ALIGN_STACK}
        ADD     ESP,8
        {$ENDIF ALIGN_STACK}
@@done:
end;
{$ENDIF CPUX86}
{$ENDIF X86ASMRTL}