Large delay in pgsql-jdbc SELECT

Hello,

I am hoping somebody might have an idea about this or a suggestion for
troubleshooting...

I am using jdbc7.1-1.2.jar with jdk1.3.1_01 on an i386 box with RedHat 7.1.

When running a SELECT query that resulted in 10 rows of 100 columns each, I
could average a 1 second response from my application.
However when I ran a similar SELECT that resulted in 100 rows of 100 columns
each (of exactly the same format), I experienced a very definitive hang of
about 20-25 seconds.

When I issued the same query within the psql prompt, the query results
returned immediately.

My application is hanging at the db.createStatement().executeQuery("SELECT
..."); statement
I turned on level 4 debugging and straced -f my postmaster and saw that it
was hanging in a recv statement in file descriptor 5 which is the
/usr/local/pgsql/data/global/pg_control file.

Debug and strace output at the hang is:

......
[pid 24706] 11:40:25 brk(0x8237000) = 0x8237000
[pid 24706] 11:40:25 write(2, "DEBUG: CommitTransactionCommand"...,
33DEBUG: CommitTransactionCommand
) = 33
[pid 24706] 11:40:25 brk(0x8213000) = 0x8213000
[pid 24706] 11:40:25 send(5,
"\0051\0\0\0\0051\0\0\0\0051\0\0\0\0051\0\0\0\0051\0\0\0"..., 1327, 0) =
1327
[pid 24706] 11:40:25 recv(5,

(It hangs here for 20 seconds)

"Qcommit\0", 8192, 0) = 8
[pid 24827] 11:43:09 write(2, "DEBUG: StartTransactionCommand\n", 32DEBUG:
StartTransactionCommand
) = 32
[pid 24827] 11:43:09 write(2, "DEBUG: query: commit\n", 22DEBUG: query:
commit) = 22
...

Top appears to reveal no memory problems, I have all my limits set to
unlimited. I see a very high level of CPU activity during this period.

Does anyone have any thoughts or recommendations?

Thanks for any help you can give me!

Scott Jackson