Is it save to modify field sysadmin:mon_users.progname from varchar(16) to lvarchar(64, 128 or 256)?
Wilhelm Seyerl asked whether it is safe to widen sysadmin:mon_users.progname from varchar(16) to lvarchar on Informix 14.10.FC4W1 to hold long DBeaver program names. Art Kagel said altering it to lvarchar(256) is safe, though an upgrade may revert it. Jacob Salomon lamented the sparse documentation; Wilhelm pointed to ph_task and sysmaster.sql as sources.
Auto-generated by Claude from the posts below — may be imperfect; read the full thread.
Hi, Currently running Informix 14.10.FC4W1. The table sysadmin:mon_users is awesome. But the column progname in the table is varchar(16) which is very short. $INFORMIXDIR/etc/sysmaster.sql has char(256) for progname which is just enough to hold the information a DBeaver session via JDBC would submit. Have seen 206 characters with the pattern: "Thread[id:68, name:DBeaver: Open connection to *** path:***/drivers/IBM/Informix/Informix_JDBC_Driver/4.10.JC10/lib/ifxjdbc.jar]". My questions are: Is it save to modify field sysadmin:mon_users.progname to lvarchar(64, 128 or 256)? Do i have to also modify sysadmin:ph_task.tk_create (where tk_name = 'mon_users')? Or may any Informix upgrade reset the new field type and length of sysadmin:mon_users.progname anyway? BR Wilhelm ------------------------------ Wilhelm Seyerl ------------------------------
Wilhelm: OK, yes it is safe to alter the progname column in mon_users to lvarchar(256). Yes an upgrade MAY alter it back to varchar(16), but usually it will not. Art ------------------------------ Art S. Kagel, President and Principal Consultant ASK Database Management Corp. www.askdbmgt.com ------------------------------
Folks, It would be helpful to know about tables like mon_users and such. But there is such a dearth of documentation available to us peons about these tables! In the admin reference there are 4 entities mentioned in the chapter on the sysadmin database. Just my $0.02(US). ------------------------------ +-----------------------------------------------------------+ | I am pleased to report that I had no problems today. | | I had only issues, opportunities, challenges and valuable | | learning experiences. | +------------------------------------------ Jacob S --------+ ------------------------------
Well,
What those mon_* tables are recording is basically documented in the
sysadmin:ph_task table.
SELECT tk_name, tk_execute, *
FROM sysadmin:ph_task
WHERE tk_name LIKE 'mon_%';
Those tk_execute statements run a lot of stuff on the sysmaster database. I
personally learned a lot by examining them.
And loads of information about the sysmaster database can be found in
$INFORMIXDIR/etc/sysmaster.sql
However, examining the sysmaster can be missleading sometimes.
Just as an - maybe very uneducated - example:
nreads, ninserts, nupdates, ndeletes on tables (sysptnhdr) may generally refer
to number of SELECT, INSERT, UPDATE and DELETE rows affected on
the respective table. While is_reads (SELECT), is_write(INSERT),
is_rwrite (UPDATE) in the session profile may refer to the number of ISAM steps
taken to accomplish the task. But some of those tables in sysmaster.sql are
explicitly marked as "for internal use only".
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Wilhelm Seyerl
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