Performance in using BLOBs

Ray.Henry · Post by **Ray.Henry** » Mon 29 Mar 2010 22:10

Hi,

Our initial testing shows that reading and writing BLOBs from Oracle 11g in Direct mode is about 30-45% slower than Microsoft's ADO.NET driver.

Is there any tuning that we can do to improve this?

1MB Blob is about 45% slower, 10MB Blob about 30%.

Thanks. Looks like a great product, we'd like to learn more about how to tune it.

Shalex · Post by **Shalex** » Tue 30 Mar 2010 13:25

We will investigate the behaviour of our provider when working with BLOBs and notify you about the results as soon as possible.

Shalex · Post by **Shalex** » Mon 12 Apr 2010 15:42

The reason of the metioned results is that Microcoft Oracleclient and ODP use the RAW type for the <=32000 bytes values in spite of the explicit setting to use BLOB. So you can set the appropriate datatype manually with dotConnect for Oracle.

Here are the results of our tests:
Microcoft Oracleclient (Raw) - 0.25
ODP (Raw) - 0.20
dotConnect for Oracle OCI (LongRaw) - 0.22
dotConnect for Oracle Direct (LongRaw) - 0.22
dotConnect for Oracle OCI (Blob) - 0.29
dotConnect for Oracle Direct (Blob) - 0.29