CODEWITHSUNDEEP
androiddatabasesqlite
wasatch14
wasatch14

Reputation: 163

Quickest way to store values in Android SQLite database?

I need to store simultaneous readings from 10 sensors into a SQLite database at about 100Hz. Which means I need to store about 1000 readings a second into the database.

I've tried putting the database insert method in a Service running in its own process but I can only collect about 3.5 seconds worth of data. I think the Service is being killed at that point.

I am not using database transactions to insert the data. Just individual calls of INSERT INTO... Is it crucial to use transactions?

Is it necessary to run the database inserts in a separate process? Can I just run them in a new thread off the main process?

I can provide code if needed.

Upvotes: 2

Views: 905

Answers (2)

CommonsWare
CommonsWare

Reputation: 1006594

I need to store simultaneous readings from 10 sensors into a SQLite database at about 100Hz

If you are referring to Android's sensors, I am uncertain you will actually get data delivered to you that quickly.

I've tried putting the database insert method in a Service running in its own process

Do not use a separate process. You are adding overhead for no benefit.

Do your database I/O from whatever component is registered with your sensors. If that's a service, fine.

I can only collect about 3.5 seconds worth of data. I think the Service is being killed at that point.

Then you have bigger problems. Processes containing running services will not be killed 3.5 seconds after launch. Somehow, your service implementation is messed up.

I am not using database transactions to insert the data

As Mr. Harvey points out, transactions are essential for performance.

Is it crucial to use transactions?

Yes.

Is it necessary to run the database inserts in a separate process?

Not only is it not necessary, it borders on the ridiculous.

Can I just run them in a new thread off the main process?

Yes.

Upvotes: 0

Robert Harvey
Robert Harvey

Reputation: 180777

You need to use transactions, and "chunk" your requests by performing multiple inserts in the same transaction. You'll have to play with the number of inserts, but I would start at 1000 inserts per transaction, and tweak it from there.

Transactions are extremely slow, if you want to insert one record at a time. The reason for this is that SQLite waits for the data to be written to disk before completing the transaction, and so has to wait for the disk platters to spin completely around, during which time the disk is essentially inactive.

On a 7200 RPM hard drive, this essentially limits transactions to 60 per second.

http://www.sqlite.org/faq.html#q19

Upvotes: 4

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