Q: some questions on db structure on alenka

[mmmoti]

Hi anton , I've looked in your project and really enjoyed on the idea and the concept.

I've being working with ORACLE RDBMS for about 15 year and have done several projects big projects. I think that using of column db and gpgu is good concept and can give a real boost to data analsis.

I've some questions regarding how you've implement column db in alenka project.

if I understand correctly , every column is represented by a file which is compress , so for example for a table with 3 columns , we'll 3 files.

1.what happens on insert statement , does the new row go the end of the file (FIFO) , I assume that the file is zipped for every insert operation (or bulk ) ? if so , what will happens if there will by serveral threads performing inserts ?

1. How do you corrdiante betweens values , for example if we got table of two columns test (a number,b number) and we run the query : select * from test where a=1 and b=2 ; How alenka retrive the correct row , is it based of row position in the file ? If so , what will happen if the insert doesn't contain data - like insert (5, null )

I hope you can help me on those questions .

Regards, Amihay

[antonmks]

Hi Amihay 1.Inserts, updates and deletes are not implemented yet in Alenka although it is on a to-do list

2. You have guessed correctly, correlation is implemented by a rowid.

Thanks !

Anton

[mmmoti]

Hi Anton , thanks for the feedback, I would like to have phone call ,I was able to compile alenka on amazon vm + cuda (you can buy such vm ) , but when running i got strange errors.

If it is possible , I'll like to coordinate such call , if so , can you send your email to agonenil@gmail dot com to discuss it farther .

[antonmks]

Hi ! Sorry, I was on a vacation, but I'm back now. I'm available on Skype and I would be happy to help you with any issues. I should note however that Alenka is not a something that you would want to use in a production - it is just my personal reseach.

Regards, Anton

On Sun, Jul 22, 2012 at 2:30 PM, Moti reply@reply.github.com wrote:

Hi Anton , thanks for the feedback, I would like to have phone call ,I was able to compile alenka on amazon vm + cuda (you can buy such vm ) , but when running i got strange errors.

If it is possible , I'll like to coordinate such call , if so , can you send your email to agonenil@gmail dot com to discuss it farther .

---

Reply to this email directly or view it on GitHub: https://github.com/antonmks/Alenka/issues/1#issuecomment-7160628

[aniongithub]

First of all - this is an awesome project. I didn't want to start a new question for a question related to the database structure - so here goes. Have you considered supporting Cassandra/HBase or some other columnar, noSQL database instead of a custom format?

Keep up the awesome work!

[antonmks]

Hi Ananth ! The reason I used a custom format is that I use compression/decompression algorithms that are not supported by HBase. The data I store are compressed with a combination of FOR (frame of reference), FOR-DELTA and dictionary compression. Reading uncompressed data into a GPU would have a significant overhead because of slow speed of data transfers between main memory and a gpu. If there is a way to store the compressed data together with some metadata in HBase structure I would be happy to support it.

Regards

Anton

On Wed, Sep 5, 2012 at 9:30 PM, Ananth notifications@github.com wrote:

First of all - this is an awesome project. I didn't want to start a new question for a question related to the database structure - so here goes. Have you considered supporting Cassandra/HBase or some other columnar, noSQL database instead of a custom format?

Keep up the awesome work!

— Reply to this email directly or view it on GitHubhttps://github.com/antonmks/Alenka/issues/1#issuecomment-8308760.