Question

I’ve got a new database here and it’s an upgraded version from Oracle 10g to Oracle 11g – the main problem is with LOB columns and everytime any function returns a LOB as result, the new database won’t return strings like the old one did:

Old DB:

["C"]=>
string(23) "3874163,3874197,3874201"

New DB:

["C"]=>
resource(182) of type (stream)

Now when reading the streams sometimes there is an error of a non-existing stream resource beeing referenced and everything fails. I’m guessing the connection closed in the meantime without the stream beeing read and therefore the access is lost.

When changing the statements to include a casting against varchar for example:

CONVERT(VARCHAR, C, 120)

Or like this:

SELECT TO_CHAR(FUNC())

The value is returned as a string again but this is not really an optimal solution as every statement would need to be changed.

Is there any way/option to prevent LOBs from beeing delivered as streams so they are instead delivered as strings like in Oracle 10g?

Edit:
We are using the oci function-set for db access.

Answer 1

Not really an answer as such but a few items that I hope helps.

It looks like that there is a small difference in the way that LOBs are returned between 10g and 11g, under 11g there is some notes about the conversion from btyes to byteStreams when LOBs are over a certain value, in the JDBC reference manual (I understand that this doesnt effect OCI calls as they use a different driver set).

From what I can see in terms of the OCI8 functions within php the default operation of the fetch functions is that the LOBs are returns as a reference and need to be accessed using the ->read() ->load() etc functions (see http://au.php.net/oci_fetch_array – regarding the mode and the default).

Now I dont know if you are using the OCI functions to access your oracle system as it’s not specified in your question.

Couple of other items that would help in figuring this out would be if you could let us know if you recompiled php or updated the oracle drivers with the newer client version at all.

I know its not a full solution but if you are using oci_fetch_* to return the row, add a second argument to the call of OCI_RETURN_LOBS, this will cause the fetch to return a string of the LOB field instead of a reference to a stream, or use the $variable["C"]->load() to access this LOB this will cause it to load the full stream and act like a normal string.

Hope this helps.