DB2E !!!

[Former Member]

Hi Everybody!!!

I am installing DB2E on my PDA with encryption!!!

Before that i want to know the effect of encryption on the performance..

1) What would the change in file DB size before and after encryption?

2)Does the no. of syncbo objects have an impact on the DB size

3) In a PDA scenario after establishing a connection with the DB2E where would the connection be stored!!!

Can someone help me in this regard!!

Thanks & Regards,

Krishna Mohan

[kishorg · Accepted solution]

Hi Krishnamohan,

<i><b><<<1) What would the change in file DB size before and after encryption?>>></b></i>

In general ,

Encryption is the process of converting data from its original form, called the "plaintext," to an unreadable form, the "ciphertext," through the application of an algorithm called a cipher. Decryption is the reverse of this process; in decryption, a ciphertext is converted back into its corresponding plaintext.

Various algorithms are used for data encryption and decryption . <b>In the case of DB2E , the used algorithm is DES(Data Encryption Standard).Compared to other algorithms, however, it is comparatively slow and has the significant drawback of only supporting 56-bit keys (a 64-bit key, less one "parity" bit for each byte).</b>

<b>Adding encryption to a database application will almost certainly decrease performance, at least minimally. Data must be encrypted before being written to disk and unencrypted every time they are read.</b>

<u><b>Encrypted data also generally increases storage requirements -- another reason for restricting the amount of data to be encrypted. Since block ciphers work on several bytes of data at a time, the binary encrypted string is typically up to one block longer than the source string. Base64 encoding will increase this overhead significantly; a rough estimate would be to

assume inflation in storage requirements by about 33% for encrypted and encoded data. Be especially cautious beforeencrypting data in files close to maximum file size.

</b></u>

For encryption and decryption additional APIs have to be loaded into the memory.If the data to be encrypted is not so crucial, that would be a burden for the mobile devices like PDA.

<b> So we can conclude , the data size will be more when comparing with the normal data as in the case of encrypted data.</b>

<i><b><<<<<2)Does the no. of syncbo objects have an impact on the DB size>>>></b></i>

The number of Sync Bos and the amount of data will increase the size of the data.

For each sync Bo , its meta data also has to be stored on the client device. As the number of fields

mapped increases , the amount of metadata information , which is to be stored also increases.

<b>In the case of DB2E , the meta data and the exact data store is located in ,

<Drive>:\Program Files\SAP Mobile Infrastructure\data\

In this folder , we can see the metadata information of individual SyncBos (TOP and ITEM in seperate files).

For each sync bo , we can see individual files.

In the case of File system . all data will come under as .dat files in <Drive>:\Program Files\SAP Mobile

Infrastructure\data\<Conversation ID for the particular application>\ ..

But in this case , the metadata information is stored in MCD level .I meant , all the TOPs of all the SyncBos will be in one file , and all the ITEMS of all the SyncBos will be there in another .dat file..

</b>

<i><b>So we can conclude , the amount of data is directly proportional to the number of used syncbos and the mapped fields...</b></i>

<i><b><<<<3) In a PDA scenario after establishing a connection with the DB2E where would the connection be stored!!!>>>>></b></i>

Its a good question. Exactly dont know.. It might be using the connection pooling mechanism !!..

Actually in the case of DB2E also , in MI , we are using the JDBC connection object to connect to DB2E .

Refer these links also ...

http://publib.boulder.ibm.com/infocenter/iwedhelp/v6r0/topic/com.ibm.db2e.doc/glu_over_db2e.html

http://publib.boulder.ibm.com/infocenter/iwedhelp/v6r0/topic/com.ibm.db2e.doc/db2elimits.html

http://publib.boulder.ibm.com/infocenter/iwedhelp/v6r0/index.jsp?topic=/com.ibm.db2e.doc/encry.html

Regards

Kishor Gopinathan

[sandeep_rs · Accepted solution]

Hi Krishnamohan,

Jo and Kishore have already answered most part of your question. I would just like to add on here for the last part of it.

Once the connection to DB2e is obtaioned it is stored in com.sap.ip.me.persist.jdbc.IBMDB2eManager class as a static variable. The same connection is reused for all the DB operations. Connection pooling is a concept more relavent to Database servers which get lots of simultaneous connection request and is a lot of overhead in MI Client scenarios (esp in PDA scenario).

Best Regards,

Sandeep

[Former Member]

Hi,

Does anyone know how to encrypt a db2e database, running with MAM 2.5 developed with SAP NW 2004 SP15 (not 2004s). Where can I find some information about the encryption of a db2e database?

Thanks,

Bart Elshout

[sandeep_rs]

Hi Bart,

To use DB2e enryption, you will have to use a seperate DB2e deployment zip at the time of installation. Once you use this DB2e_enrypt version during installation, all data tables further created will have its data encrypted.

Unfortunately, if you are already have data on your device, you cannot use DB2e encryption without requiring to reset the client database first and do an initial download of data again.

Best Regards,

Sandeep

[Former Member]

hello !

As i havnt posted the original question,i am not able to reward your answers.

Sorry for that.

And thanks a lot for your help.

I wil post a new question on my name.

Regards

-Rucha

[Former Member]

Hi everybody!

Even i have installed DB2E on PDA.But if i want to configure the database to reside on the flash card ,then how should i proceed? or this is internally managed by the OS?

[sandeep_rs]

Hi Atre,

You can check note 746783 which speaks on how to install ME on a flash card. Its relevant for installation of MI too.

Please note that DB2e is mandatory for having ME/MI on flash card and also only CF cards are ok but not SD cards.

Best Regards,

Sandeep

[Former Member]

Hi Arte,

To just change your data folder to CF card you can add the following parameters to MobileEngine.config file

MobileEngine.Persist.RootDir.isAbsolute=true MobileEngine.Persist.Rootdir= <CFCard directory>

Hopefully your problem should be solved!

Best Regards,

Karthik

[Former Member]

hello krish,

i haven't tried this with DB2E though...

1) What would the change in file DB size before and after encryption?

this depends on which type of encryption you are employing.

i would suggest that you try it with a smaller db data

and see the effects with the increase in encryption strength

and for several types of encrypting methods as well.

2)Does the no. of syncbo objects have an impact on the DB size

yes. the more syncbo objects you have, the greater your

db volume will be.

3) In a PDA scenario after establishing a connection with the DB2E where would the connection be stored!!!

im not sure if the DB2E driver for MI supports connection

serialization. maybe it does for the background sync

feature when there are 2 threads accessing the database.

for the location, this could be DB2E-specific... perhaps

this could be specified into the Property parameter when

the Connection is created. i think decompiling and checking

on the com.sap.ip.me.persist.jdbc.IBMDB2eManager class

will give you an idea if connection serialization is

supported. for details you can refer to IBM site- <a href="http://publib.boulder.ibm.com/infocenter/weahelp/topic/com.ibm.websphere.db2e.doc/welcome.html">DB2E</a>.

let's wait for replies from MI developers anyway...

regards

jo