how to create a database ?

[BjornF]

Hmm, that is more difficult. I think that is beyond the level of my competence, sorry

Björn

[Stellaferox]

No problem, you've been helpful.
Anyone else?

[agraham]

Originally Posted by Stellaferox

Just a question that pops into mind: is there a way to create a CSV-database, using the FileWrite method?

Yes, but as the answer is simple I may not have understood your problem

text = "values1" & "," & "value2" & "," & .....
FileWrite(c1, text)

[Stellaferox]

Agraham,

That might work well, but I need roughly 133 million entries (with equivalent comma's) in a single textstring then. Will that work?

[agraham]

Originally Posted by Stellaferox

I need roughly 133 million entries (with equivalent comma's) in a single textstring then. Will that work?

Probably not! But it begs the question - Why do you need to save that much data to a csv file as a single line?

[Stellaferox]

Well, I dont NEED to write it as a single line. I need to write 133784560 entries in a CSV, comma separated file. Then I want to read it in an array using the splStringfeature using the commaseparator.
Later on when having checked the data I will use a binary file (I need to sort the data first).
Marc

[agraham]

Why do you need to write it to a CSV file and then reread it all back in again? I assume you are generating the data within the program. Unless it takes a lot of processing to generate each data point it might well be quicker to just generate the data straight into the array rather than doing a whole lot of string processing on it.

Also that is a huge amout of data that will occupy a huge amount of memory. If it were Int32s it is nearly half a Gigabyte, as Strings it could be even more! Unless your PC has a lot of memory your app will cause Windows to page stuff to and from disk and slow down processing to a crawl. Are you sure that you have structured your app and its' data in the optimum way.

[Stellaferox]

Agraham,

You are right. I am generating the code from inside and then building a "mothertable". I have to eyeball the data, hence the CSV format.
Later I want to read in the data in an array and after some work, split up the mothertable in a few smaller ones with indexes. Then I can use BinaryFile options. That is the main idea.
I need to optimize my code (lot easier in the earlier days with assembly languages, but Basic4PPC doesn support this (yet)).
Because computing from code takes a lot longer then reading a table (using binary search) I am able to have any entry I want in a 133 million base within 27 steps maximum.
Marc

[agraham]

Originally Posted by Stellaferox

I have to eyeball the data, hence the CSV format.

You can't possibly eyeball all 133Mitems. Why not just generate the data into an array then put some testing code in to write out selected chunks of it to MsgBoxes or to small text files, they don't have to be CSV files to be readable.

Because computing from code takes a lot longer then reading a table (using binary search) I am able to have any entry I want in a 133 million base within 27 steps maximum

Sorry - you missed my point. I meant generate all the items into the array rather than read all those items from a file and then do your lookups and build your smaller tables. Although for 27 steps involving 27 equality checks to save any time it must be a relatively long algorithm to generate the data? Also that implies sorting the table. Unless you can generate the data in sorted form that could take a long time as well. Have you done any timings to estimate how long this mammoth thing will take to run?

lot easier in the earlier days with assembly languages, but Basic4PPC doesn support this (yet)

It probably never will as B4PPC outputs C# code which is compiled to IL (intermediate language) and written to the exe which the .NET Framework CLR (Common Language Runtime) JITs (Just In Time compiles) it at runtime to "safe" machine code. All this is done to stop humans fiddling with Assembly code and making mistakes. There are ways to cross over into "unsafe" code in DLLs but for B4PPC that would need a library and I'll go out on a limb and bet that Erel will never support this natively in B4PPC. If you are enough of an anorak (like me) you can buy books to find out how IL and the CLR works.

[Erel]

@agraham
I think that this one is pretty thorough:
http://www.amazon.com/Expert-NET-2-0...3008169&sr=8-1