IDS Forum

RE: Time delay on ipcshm connection versus tlitcp

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Date:

Tracy,

Were these two tests run one after the other?
Did we shutdown and bring up the instance?
Were the tests run more than once giving the same results?

I have seen many a test run where the second test through shows great
improvment. The reson is obivous once you think about it. The first time
through the engine cached all the needed pages into memory. The second time
there was no need to go to disk. In later engines SQL Statement caching
also causes more speed gains in the second pass. All the Optimizer needs to
do is see this is a recently run query.

If these were tests done on a level playing field then the question becomes
more interesting.

George

-----Original Message-----
From: Tracy Sweeney [mailto:sweentra@pentamation.com]
Sent: Tuesday, March 11, 2003 10:38 AM
To: ids@iiug.org
Subject: Time delay on ipcshm connection versus tlitcp [645]


Hello all:

I have a UnixWare 7.1.1 System running IDS 7.31.UD5. I have two
connections set up as follows:

#TCP/IP Link For GSMS and COGNOS
aspdb03 ontlitcp aspdb03 sqlexec

#Interprocess communications link - For Open Series
ipcdb03 onipcshm aspdb03 db03sql2

When I time a simple sql command with dbaccess I get a significant delay
on the ipc connection in the amount of real time used. I thought shared
memory connections were supposed to be faster? Am I missing something in
my configuration? It looks like the actual command runs quickly and the
display prints the Database closed line, but then a delay occurs before
returning to the command line and the real time is very much higher that
with the tlitcp connection.

support: echo $INFORMIXSERVER
ipcdb03
support: time dbaccess pmpfinance /peishare/hosting/sql/sql1.sql

Database selected.
(count(*))
1135
1 row(s) retrieved.
Database closed.

real 0m1.05s <-----
user 0m0.01s
sys 0m0.03s

support: echo $INFORMIXSERVER
aspdb03
support: time dbaccess pmpfinance /peishare/hosting/sql/sql1.sql

Database selected.
(count(*))
1135
1 row(s) retrieved.
Database closed.

real 0m0.06s <-------
user 0m0.03s
sys 0m0.00s

Here are my onconfig entries in the nettype:
NETTYPE tlitcp,2,200,NET # Configure poll thread(s) for nettype
NETTYPE ipcshm,2,200,CPU # Configure poll thread(s) for nettype

Messages In This Thread

• Time delay on ipcshm connection versus tlitcp
  Tracy Sweeney -- Tuesday, 11 March 2003, at 12:37 p.m.
  • RE: Time delay on ipcshm connection versus tlitcp
    Palmer, George -- Tuesday, 11 March 2003, at 2:47 p.m.

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