SQL Anywhere Mobile - Order of table in synch & timing

Author

Order of table in synch & timing

Toni

2005-10-27, 8:21 am

Hi,

ASE 12.5.0 Vs ASA 901.1996, ASE on unix and ASA on pc.
Try to synch at the first time to get database from
Consolidate to mblink and it took about 1.5 hrs with size of
local db ~21,000kb.
Beside that it get an error message about Referential
Integrity problem and the synch was terminated. Does the
synch know the order of table to download in order to avoid
RI problem ????
We have the publication with order of table based on
alphabetical order.

1. We would like to know if we have to set order of table
for download or it will automatically generate from mblink.
2. We used to use SSXtract to unload data from consolidate,
then reload it back to remote user and it take only 10 min.
We don't see any similar in mobilink except mlxtract for ASA
only.
Any idea or suggestion about those issues.
thank you,
Toni

David Fishburn

2005-10-27, 8:21 am

Toni wrote in news:434d552c.1ad.1681692777@sybase.com
of sybase.public.sqlanywhere.mobilink:

T> ASE 12.5.0 Vs ASA 901.1996, ASE on unix and ASA on pc.
T> Try to synch at the first time to get database from
T> Consolidate to mblink and it took about 1.5 hrs with size of
T> local db ~21,000kb.

How many rows were downloaded? You can get this information in one of 2
ways:
1. Start the MobiLink Monitor and see its output graphically.
2. Start MobiLink using -vn, this will show row counts at the end of
each sync.

T> Beside that it get an error message about Referential
T> Integrity problem and the synch was terminated. Does the
T> synch know the order of table to download in order to avoid
T> RI problem ????

Sure, use declarative referential integrity when you create the remote
database.

create table parent (
pid int,
c2 char(30),
primary key(pid)
);

create table child (
pid int,
cid int,
c3 char(30),
primary key(pid, cid)
foreign key (pid) references parent(pid)
);

T> We have the publication with order of table based on
T> alphabetical order.

True, that is the reason to use declarative RI.
The other option (but not nearly as effective) is to use the TableOrder
extended option. It is a bit better than alphabetical.

T> 1. We would like to know if we have to set order of table
T> for download or it will automatically generate from mblink.

No, see above.

T> 2. We used to use SSXtract to unload data from consolidate,
T> then reload it back to remote user and it take only 10 min.
T> We don't see any similar in mobilink except mlxtract for ASA
T> only.

It takes only 10 minutes for a variety of reasons.
First, it uses LOAD TABLE statements, which are not logged. No
transaction log growth.
It does each table in 1 transaction (no rollback log growth).

dbmlsync has to maintain data consistency.
So, all the rows are added in ONE transaction.
It can be rolled back (as in fact you saw with the RI errors) so
therefore you get the overhead of proper transactions and rollback logs.

Depending on what platform the remote is one, and the amount of cache
provided, this can take sometime.

For example, if this is a CE device, flash memory is _very_slow. They
have limited memory, so the cache cannot be very large.

NOTE:
You can do the same thing you did with SSRemote.
Build the remote on the server and send the finished database and log
file to the device.

--
David Fishburn
Certified ASA Developer Version 8
iAnywhere Solutions - Sybase
Professional Services
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