SQLite parallel insert

ROOT
1

Dear ROOTers
Is there an way to insert records to sqlite database in parallel mode (e.g. many jobs in farm)? I found some examples in sqlite3 API that check if DB is locked or not, but I can’t see similar functions in ROOT API.

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2

Hi @dwielane ,
what ROOT API are you using to work with sqlite3 files?

Cheers,
Enrico

3

Hi,
Im using this ROOT TSQL classes. I saw some solutions that use “raw” sqlite library.

4

I see, then @linev might know whether we have a way to do parallel writes with the TSQL* classes

5

How these solutions looks like?
Is it special SQL requests or special API calls?

P.S. I had no experience with SQLite till now. But I hope it is possible to use/extend TSQLServer API if necessary

6

Actually I thougt about transactions, they can be done via current root interface (I suppose) but I would like also check the status of transactions by using sqlite3_get_autocommit but I don’t see such option in ROOT.

7

It sounds like you might want to use sqlite3 directly, ROOT’s interfaces will probably never offer the same amount of features.

8

Hi,

In TSQLServer class there are three methods to control transactions:
StartTransaction(), Commit(), Rollback()

Only first method is implemented for TSQLiteServer class.
There is no problem to add implementation for remaining two - API is very simple and can be read here: BEGIN TRANSACTION - Using SQLite [Book]

And one can introduce extra method like TSQLServer::IsTransaction() which will use sqlite3_get_autocommit function inside.

I can provide PR. @dwielane, will you be able to test it?

Regards,
Sergey

9

Here is PR with proposed changes, please test it before I can commit it into the master

1 Like
10

@dwielane
Did you check that new methods work for you?
Can I merge PR?

11

Dear @linev ,
I have collaboration meeting this week so I will not be able to check this solution today, could I answer in next week?

12

No problem, next week is absolutely ok

13

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14

@dwielane any news here?

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