SQL Anywhere Mobile - is a timestamp column is required?

Author

is a timestamp column is required?

vsv

2005-08-18, 8:25 pm

http://www.sybase.com/detail?id=1034174

i have a table with download_script select *
from employee

Also I have the table in publication in the remote.
Will it download the data everytime I download OR only the changes in the
consolidated since last download. The above document link says you have to
add a column & modify the query with where last_updated > ? to avoid
downloading it every time..

However, my query does without that field itself.
How is it doing?

Does mobilink reads the consolidated transaction log file or check points to
determine the download in combination with the other records in ml_*
tables.?
A document link that will best describe will be great.

The mobilink basic document doesn't explain how it determines the records to
be downloaded other than that it says it uses the download_cursor script.

thanks in advance.
vsv

Breck Carter [TeamSybase]

2005-08-18, 8:26 pm

Your script will download all the employee rows every time. The
MobiLink server does not use the consolidated database log at all; it
simply executes exactly what you code in the download_cursor script.

MobiLink *does* provide two parameters to the the download_cursor
script: the last download date/time, and the current MobiLink user
name. You can refer to those values in your select by coding one or
two ? characters.

Breck

On 18 Aug 2005 13:20:21 -0700, "vsv" <nospam@nospam.com> wrote:

>http://www.sybase.com/detail?id=1034174
>
>i have a table with download_script select *
>from employee
>
>Also I have the table in publication in the remote.
>Will it download the data everytime I download OR only the changes in the
>consolidated since last download. The above document link says you have to
>add a column & modify the query with where last_updated > ? to avoid
>downloading it every time..
>
>However, my query does without that field itself.
>How is it doing?
>
>Does mobilink reads the consolidated transaction log file or check points to
>determine the download in combination with the other records in ml_*
>tables.?
>A document link that will best describe will be great.
>
>The mobilink basic document doesn't explain how it determines the records to
>be downloaded other than that it says it uses the download_cursor script.
>
>thanks in advance.
>vsv
>

--
SQL Anywhere Studio 9 Developer's Guide
Buy the book: http://www.amazon.com/exec/obidos/A...7/risingroad-20
bcarter@risingroad.com
RisingRoad SQL Anywhere and MobiLink Professional Services
www.risingroad.com

vsv

2005-08-18, 8:26 pm

But my log on the local database doesn't have as many inserts and/or
failures. So, does the mobilink client filters the records based on the
last_date_time?
thanks
vsv

"Breck Carter [TeamSybase]" < NOSPAM__bcarter@risi
ngroad.com> wrote in
message news:ov3ag1h2p8qufh5
1t36sifoglebausufn2@
4ax.com...
> Your script will download all the employee rows every time. The
> MobiLink server does not use the consolidated database log at all; it
> simply executes exactly what you code in the download_cursor script.
>
> MobiLink *does* provide two parameters to the the download_cursor
> script: the last download date/time, and the current MobiLink user
> name. You can refer to those values in your select by coding one or
> two ? characters.
>
> Breck
>
> On 18 Aug 2005 13:20:21 -0700, "vsv" <nospam@nospam.com> wrote:
>
to[color=darkred]
to[color=darkred]
to[color=darkred]
>
> --
> SQL Anywhere Studio 9 Developer's Guide
> Buy the book:
http://www.amazon.com/exec/obidos/A...7/risingroad-20
> bcarter@risingroad.com
> RisingRoad SQL Anywhere and MobiLink Professional Services
> www.risingroad.com

Breck Carter [TeamSybase]

2005-08-18, 8:26 pm

Any downloaded rows that violate referential integrity constraints on
the remote will be skipped by default... that is one way fewer rows
can appear on the remote than the consolidated.

Run dbmlsrv9 with -o filespec.txt -v cfhnprstu to record everything
being downloaded, or -o filespec.txt -v cfhnpstu to record everything
interesting except row values.

Also run dbmlsync with -o filespec.txt -vnorsu to record everything
being downloaded, or -o filespec.txt -vnosu to record everything
interesting except row values.

Then study the text files to see what's happening.

You might find Chapter 7 of the book helpful.

Breck

On 18 Aug 2005 16:28:04 -0700, "vsv" <nospam@nospam.com> wrote:

>But my log on the local database doesn't have as many inserts and/or
>failures. So, does the mobilink client filters the records based on the
>last_date_time?
>thanks
>vsv
>
>"Breck Carter [TeamSybase]" < NOSPAM__bcarter@risi
ngroad.com> wrote in
>message news:ov3ag1h2p8qufh5
1t36sifoglebausufn2@
4ax.com...
>to
>to
>to
>http://www.amazon.com/exec/obidos/A...7/risingroad-20
>

--
SQL Anywhere Studio 9 Developer's Guide
Buy the book: http://www.amazon.com/exec/obidos/A...7/risingroad-20
bcarter@risingroad.com
RisingRoad SQL Anywhere and MobiLink Professional Services
www.risingroad.com

Greg Fenton

2005-08-19, 3:26 am

Breck Carter [TeamSybase] wrote:
>
> You might find Chapter 7 of the book helpful.
>

For those just tuning in...

"the book" is "SQL Anywhere Studio 9 Developer's Guide"

http://www.amazon.com/exec/obidos/A...7/risingroad-20

greg.fenton
--
Greg Fenton
Consultant, Solution Services, iAnywhere Solutions
--------
Visit the iAnywhere Solutions Developer Community
Whitepapers, TechDocs, Downloads
http://www.ianywhere.com/developer/

Graham Hurst

2005-08-24, 8:25 pm

The remotes efficiently ignore redundant inserts and updates. As a
result, they are not recorded in the log and any corresponding triggers
are not fired.

Cheers,

Graham

vsv wrote:
> But my log on the local database doesn't have as many inserts and/or
> failures. So, does the mobilink client filters the records based on the
> last_date_time?
> thanks
> vsv

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