Classics Forum

RE: Could not do physical order read to fetch next ro

Posted By:
Date:

Hi,

I will go out on a limb here with some assumptions.

1) None of the threads are issuing a "set lock mode to wait"
2) The "log table" is not a large table or is not indexed.
3) Update statistics has not been run against the log table.

What I think may be happening is the update statements are locking each
other out, because the query parser has decided to find the rows to update
by sequntial scan. The first update to put a lock on a row will stop all
who follow it through the table ( sequntial scan of a table with a lock
somewhere and no lock mode wait will always find the lock )

I would check the indexing of the "log table" against the update statement
to see if an index is useable, and run update statistics for the log table.
Also check the length of time a lock is held. Do you issue the update row,
and run a report before committing the update?

A little more info on the log table might be helpful, structure, size,
number of rows, and indexes. And it would also be helpful to know the
update statement that is failing.

-----Original Message-----
From: DEVENDRA RAJPUT [mailto:devendrasinh.makwana@patni.com]
Sent: Thursday, March 06, 2003 12:20 AM
To: classics@iiug.org
Subject: Could not do physical order read to fetch next ro [129]


Subject: Could not do a physical-order read to fetch next row

I am using around 20 Java threads that runs simultaneously.
A common 'Log table' is referred by these threads & updates a 'flag column'

However, the rows updated are different in each of these threads.
I have tried with both Java PreparedStatement & Statement classes.
But, the SQL problem still persists. This indicates that the problem lies
in the database lock configuration related stuff on the table.

Moreover, if I run 1 thread at a time, then the program runs successfully.

How can I update the same table, but different rows simulateously from 20
threads ?????????

Messages In This Thread

• Could not do physical order read to fetch next ro
  DEVENDRA RAJPUT -- Tuesday, 15 April 2003, at 3:55 p.m.
  • Re: Could not do physical order read to fetch next ro
    Doug Lawry -- Tuesday, 15 April 2003, at 3:55 p.m.
    • Re: URGENT- NEED ISQL 7.X for MS-DOS
      ART KAGEL, BLOOMBERG/ 731 LEXIN -- Tuesday, 2 January 2007, at 9:31 a.m.
      • Re: URGENT- NEED ISQL 7.X for MS-DOS
        LazarusGOP@aol.com -- Tuesday, 2 January 2007, at 10:41 a.m.
  • RE: Could not do physical order read to fetch next ro
    Palmer, George -- Tuesday, 15 April 2003, at 3:55 p.m.
    • RE: Could not do physical order read to fetch next ro
      Richard_Stanford@exe.com -- Tuesday, 15 April 2003, at 3:55 p.m.

Classics Forum is maintained by Administrator with WebBBS 5.12.