Direct Mode performance vs OCI mode

espiralms · Post by **espiralms** » Tue 23 May 2017 13:29

Hello again
We are planning to buy DevArt dotConnect for Oracle in order to use Direct Mode, but we are worried about performance.

This link (https://www.devart.com/dotconnect/oracl ... tMode.html) explains that performance is similar in OCI and Direct Mode, but it also says this: "Statement caching is not available"
Does it mean that query caching is disabled in Direct Mode in all cases?

We also examined the performance comparative:
https://www.devart.com/dotconnect/oracl ... mance.html
Regarding DevArt DotConnect numbers, are they measured with OCI or Direct Mode?

Thank you very much !!!!!

espiralms · Post by **espiralms** » Fri 26 May 2017 08:15

Hello again!!
Can anyone help?
Many many thanks!!!

Pinturiccio · Post by **Pinturiccio** » Fri 26 May 2017 14:48

Yes, the OCI mode is faster then Direct, but the difference is negligible. If you find a significant performance difference between the OCI and Direct modes, please inform us, and we will study this issue.

espiralms wrote:This link (https://www.devart.com/dotconnect/oracl ... tMode.html) explains that performance is similar in OCI and Direct Mode, but it also says this: "Statement caching is not available"
Does it mean that query caching is disabled in Direct Mode in all cases?

It is mean the following feature: https://www.devart.com/dotconnect/oracl ... ching.html
So query caching is disabled in the Direct mode in all cases.

espiralms wrote:We also examined the performance comparative:
https://www.devart.com/dotconnect/oracl ... mance.html
Regarding DevArt DotConnect numbers, are they measured with OCI or Direct Mode?

These are old examples. The OCI mode is used in these examples. We are working on an up-to-date performance comparison, but we can't tell any timeframe when it is done at the moment.

espiralms · Post by **espiralms** » Mon 29 May 2017 15:14

Many many thanks for this response.

But I am a bit confused!! How can Direct Mode performance be equal to OCI, considering that statement caching is not available on Direct Mode?
I assume PL-SQL parsing operations are usually heavy.

Probable we lack some Oracle knowledge somewhere... Can you please illuminate us?

Best regards!!!

Pinturiccio · Post by **Pinturiccio** » Tue 30 May 2017 14:34

We did not write that performance in the OCI and Direct modes is equal. We have written that OCI is faster than Direct, and statement caching is one of the reasons, but the difference in most cases is negligible. If you found a significant performance difference between the OCI and Direct modes, please inform us, and we will study this issue.

espiralms · Post by **espiralms** » Mon 19 Jun 2017 13:24

Hello again
We have done some tests, please have a look.

We have a table in Oracle database, with 28 millions of row.

We have developed a very simple console application (C#) that connects to Oracle database (with DotConnect Standard edition). It performs a "select * from table" query, it iterates along all rows with a Reader.

The have done 2 experiments, both with the same Database, same data, same query (select * from table) and same code:
- Direct Mode: it spends > 240 seconds
- OCI Mode: 180 seconds aprox.

The query is all the same, with only one execution, so no caching issues involved. We have repeated many days in different days, and same results.

Could you please have a look? We can provide C# source code is needes (but its very simple)

Thank you very much
Best regards

espiralms · Post by **espiralms** » Thu 22 Jun 2017 14:26

Hello again
We need help with this issue, this is blocking our project for using Direct Mode in our deployment.
Can anyone please help?

Thank you very much in advance
Best regards

Pinturiccio · Post by **Pinturiccio** » Thu 22 Jun 2017 14:31

We have reproduced the issue. We will investigate it and post here about the results as soon as possible.

espiralms · Post by **espiralms** » Thu 22 Jun 2017 14:51

Many thanks!
We will be waiting for the response.
Best regards

espiralms · Post by **espiralms** » Tue 27 Jun 2017 07:03

Dear friends
Have you got any result with this topic?
This is a blocking issue for our project.
Thank you in advance!!

Pinturiccio · Post by **Pinturiccio** » Fri 30 Jun 2017 15:35

We are working on the issue and will post here when we get any results.

espiralms · Post by **espiralms** » Thu 06 Jul 2017 08:24

Hello again.
Have you got any estimation for the response?
This is an important matter for us.
Thank you very much!
Best regards

Pinturiccio · Post by **Pinturiccio** » Mon 10 Jul 2017 15:19

We will post some results on this issue this week.

espiralms · Post by **espiralms** » Wed 12 Jul 2017 11:02

Ok, thank you very much.
This is a blocking issue for us.
Best regards

espiralms · Post by **espiralms** » Thu 20 Jul 2017 14:32

Hello again
We are still blocked and in need for an answer.
Please, can you help?
Thank you very much

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