Large Database Access

[Jhdeval]

So I have a lot of dbf files and some are quite large. I just ran into a table being accessed by dBase.Net and the users at the same time and it left the dbf half wrote. How do you handle preventing this without a file lock? Since records are at the end of the table could we read to the end of records and then write the insert just before the end? This should also speed writes up correct?

[Jhdeval]

Ok I have put together a very run method to perform the write to end. My testing shows copy a 500 meg DBF took roughly 6 seconds. This method eliminates the streams. Since foxpro is a 32 bit file structure the files cant be larger then 2GB while that is a lot to have in memory reading from memory is WAY faster.

`
void fileCopy_usingFile(string path)
{
byte[] file = File.ReadAllBytes(path);
byte eofChar = file[ file.Length - 1 ];

var version = file[0];

var year = 1900 + file[1];
var month = file[2];
var day = file[3];
DateTime LastUpdate = new DateTime(year, month < 1 ? 1 : month, day < 1 ? 1 : day);
if (LastUpdate.Year <= 1980)
{
    LastUpdate = LastUpdate.AddYears(100);
}

byte[] bNumRecords = [file[4],file[5],file[6],file[7]];
byte[] bHeaderLength = [file[8], file[9]];
byte[] bRecordLength = [file[10],file[11]];

int NumRecords = BitConverter.ToInt32(bNumRecords);
int HeaderLength = BitConverter.ToInt16(bHeaderLength);
int RecordLength = BitConverter.ToInt16(bRecordLength);

int recordLen = file.Length - (RecordLength + 1);
byte[] LastRecord = new byte[RecordLength];
System.Buffer.BlockCopy(file, recordLen, LastRecord, 0, RecordLength );

byte[] newFile = new byte[file.Length + LastRecord.Length];

System.Buffer.BlockCopy(file, 0, newFile, 0, file.Length);
System.Buffer.BlockCopy(LastRecord, 0, newFile, file.Length, LastRecord.Length);

int fileLen = file.Length;
int lastrecordLen = LastRecord.Length;
int newfileLen = newFile.Length;

File.WriteAllBytes("./soordeha_test.dbf",newFile);

}
`