Delphi – How to access databases from within Delphi XE Professional IDE

I don't know if Firebird actually supports milliseconds, but I know for a fact that the InterBase driver for Delphi 2007 does not. This is because InterBase does not return milliseconds in its C API; although InterBase stores DateTimes to sub-milliseconds precision, the InterBase API returns times in a C TM struct which does not contain a millisecond field. Therefore, the dbExpress driver designed for InterBase is not going to support that. So, you will need to change drivers at a minimum, presuming that Firebird actually supports this at all.

I decided to conduct a little performance research: UniDAC (5.0.1) vs FireDAC (8.0.1), on Delphi XE3. Databases: Firebird, MySQL & SQL Server.

Here are the 150k records fetch results (memory usage was considered as the difference between before and after fetching).

Firebird:

CREATE TABLE TEST_PERF (
    ID  INTEGER PRIMARY KEY,
    VC  VARCHAR(200),
    NM  NUMERIC(18,2),
    DT  TIMESTAMP
)

UniDAC - 0,909 seconds, ate 12 324 044 of memory

FireDAC - 0,967 seconds, ate 282 179 668 of memory (I'm shocked)

MySQL:

CREATE TABLE TEST_PERF (
    ID  INTEGER PRIMARY KEY,
    VC  VARCHAR(200),
    NM  NUMERIC(18,2),
    DT  DATETIME
)

UniDAC - 0,363 seconds and 11 552 604 of memory

FireDAC - 0,713 seconds and 49 375 108 of memory

SQL Server:

CREATE TABLE TEST_PERF (
    ID  INTEGER PRIMARY KEY,
    VC  VARCHAR(200),
    NM  NUMERIC(18,2),
    DT  DATETIME
)

UniDAC - 0,391 seconds and 14 155 576 of memory

FireDAC - 0,324 seconds and 51 775 844 of memory

Everything was measured simply:

function MemoryUsed: Cardinal;
var
  st: TMemoryManagerState;
  sb: TSmallBlockTypeState;
begin
  GetMemoryManagerState(st);
  Result := st.TotalAllocatedMediumBlockSize + st.TotalAllocatedLargeBlockSize;
  for sb in st.SmallBlockTypeStates do
    Result := Result + sb.UseableBlockSize * sb.AllocatedBlockCount;
end;

  UniQuery1.SQL.Text := 'select * from test_perf';
  UniQuery1.SpecificOptions.Values['FetchAll'] := 'True';
  mem := MemoryUsed;
  tc := Now;
  UniQuery1.Open;
  UniQuery1.Last;
  tc := Now - tc;
  mem := MemoryUsed - mem;
  Memo1.Lines.Add('UniDAC Firebird: Time: ' + FloatToStr(tc * 24 * 60 * 60) + ' sec; Memory used: ' + IntToStr(mem));

  ADQuery1.SQL.Text := 'select * from test_perf';
  ADQuery1.FetchOptions.Mode := fmAll;
  mem := MemoryUsed;
  tc := Now;
  ADQuery1.Open;
  ADQuery1.Last;
  tc := Now - tc;
  mem := MemoryUsed - mem;
  Memo1.Lines.Add('FireDAC Firebird: Time: ' + FloatToStr(tc * 24 * 60 * 60) + ' sec; Memory used: ' + IntToStr(mem));

If anyone is interested, here is the test application, you can add there performance comparison for ADO, dbExpress, ZeosLib, and others you are interested in.