The Informix Zone - smi-query-series

SMI Query Series - Dbspace Sizes

eherber — Thu, 10 Jul 2008 21:25:17 +0200

SMI Query Series - Dbspace Sizes

The sysmaster interface (SMI) presents a comfortable way to extract information about various parts of your running IDS instance. This information can be used for:

ad hoc analysis of performance problems
determining the status of several IDS sub components
monitoring replication metrics
sampling data for capacity planning purposes
tracking system usage of individual sessions
and many more...

The below SMI query is the fith one of a new SMI query series at The Informix Zone. The queries show you how to extract valuable information from the sysmaster database.

smi_dbspace_size.sql

The purpose of this SMI query is to display the individual sizes of all dbspaces in your IDS instance:

-- ****************
-- normal dbspaces
-- ****************
SELECT 
   sd.name[1,18],
   SUM(sc.chksize * ( SELECT sh_pagesize FROM sysshmvals)) / (1024*1024) mb_allocated,
   SUM(sc.nfree * ( SELECT sh_pagesize FROM sysshmvals)) / (1024*1024) mb_free,
   100 / SUM(sc.chksize) * SUM(sc.nfree) percent_free
FROM sysdbspaces sd, syschunks sc
WHERE sd.dbsnum = sc.dbsnum
AND   sd.is_sbspace = 0
AND   sd.is_blobspace = 0
GROUP by sd.name
 
UNION
 
--  *************
--  blob dbspaces
--  *************
SELECT
   sd.name[1,18],
   SUM(sc.chksize * ( SELECT sh_pagesize FROM sysshmvals)) / (1024*1024) mb_allocated,
   SUM(sc.nfree * sdt.pagesize) / (1024*1024) mb_free,
   100 / SUM(sc.chksize) * SUM(sc.nfree * sdt.pagesize) / ( SELECT sh_pagesize FROM sysshmvals) percent_free
FROM sysdbstab sdt, sysdbspaces sd, syschunks sc
WHERE sd.dbsnum = sc.dbsnum
AND   sd.dbsnum = sdt.dbsnum
AND   sd.is_blobspace = 1
GROUP by sd.name
 
UNION
 
--  ******************
--  smartblob dbspaces
--  ******************
SELECT
   sd.name[1,18],
   SUM(sc.chksize) * ( SELECT sh_pagesize FROM sysshmvals) / (1024*1024) mb_allocated,
   SUM(sc.udfree) * ( SELECT sh_pagesize FROM sysshmvals) / (1024*1024) mb_free,
   100 / SUM(sc.chksize) * SUM(sc.udfree) percent_free
FROM sysdbspaces sd, syschunks sc
WHERE sd.dbsnum = sc.dbsnum
AND sd.is_sbspace = 1
GROUP by sd.name
ORDER BY 4;

SMI Query Series - Logical Log Space Used

eherber — Fri, 18 Apr 2008 11:08:31 +0200

SMI Query Series - Logical Log Space Used

The sysmaster interface (SMI) presents a comfortable way to extract information about various parts of your running IDS instance. This information can be used for:

ad hoc analysis of performance problems
determining the status of several IDS sub components
monitoring replication metrics
sampling data for capacity planning purposes
tracking system usage of individual sessions
and many more...

The below SMI query is the fourth one of a new SMI query series at The Informix Zone. The queries show you how to extract valuable information from the sysmaster database.

smi_log_used.sql

The purpose of this SMI query is to display the used and total logical log space. The corresponding onstat command is: onstat -l:

SELECT SUM
       (
         size *
         (
            select sh_pagesize from sysshmvals
         )/1024/1024
      ) mb_used_and_total
FROM   syslogs
WHERE uniqid >=
       (
       SELECT min(tx_logbeg)
          FROM  systrans
          WHERE tx_logbeg > 0
       )
OR     is_backed_up = 0
 
UNION ALL
 
SELECT SUM
       (
         size *
         (
            select sh_pagesize from sysshmvals
         )/1024/1024
       )
FROM   syslogs;

Examplary Output:

mb_used_and_total 
 
120.00
400.00

In the above example we have a total configured logical space of about 400 mb. Currently 120 mb of the total log space is either used by ongoing transactions or because certain logs have not been backed up yet. There is about 280 mb of free log space available on the IDS instance. Actually there might be more than 280 mb because the current logical log is considered to be full by this query. You might further adjust the SMI query and select the sum(syslogs.used) column for the current log (syslogs.is_current=1) if you prefer. The available log space for ongoing transactions might be further limited by the LTXHWM/LTXEHWM (Long Transaction Highwater Marks) settings in your onconfig file.

The above query has been tested with IDS 10. It should also run with IDS versions >= 9.30. In IDS <= 9.30 you might also need to check the column syslogs.is_new because newly added logs are not immediately available for use. A Level-0-Backup has to be taken first.

SMI Query Series - Shared Memory Segments

eherber — Tue, 04 Mar 2008 18:25:15 +0100

SMI Query Series - Shared Memory Segments

The sysmaster interface (SMI) presents a comfortable way to extract information about various parts of your running IDS instance. This information can be used for:

ad hoc analysis of performance problems
determining the status of several IDS sub components
monitoring replication metrics
sampling data for capacity planning purposes
tracking system usage of individual sessions
and many more...

The below SMI query is the third one of a new SMI query series at The Informix Zone. The queries show you how to extract valuable information from the sysmaster database.

smi_mem_seg.sql

The purpose of this SMI query is to display the allocated, used and free number of megabytes for the individual IDS shared memory segment areas:

Resident Segment
Virtual Segment(s)
Message Segment

The corresponding onstat command is: onstat -g seg

SELECT DECODE
       (
         seg_class,
         1, "Resident",
         2, "Virtual",
         3, "Message"
       ),
       COUNT(*) count_seg,
       (SUM(seg_blkused + seg_blkfree)*4/1024) mb_total,
       (SUM(seg_blkused)*4/1024) mb_used,
       (SUM(seg_blkfree)*4/1024) mb_free
FROM  syssegments
GROUP BY 1
ORDER BY 1;

SMI Query Series - Database Size

eherber — Wed, 30 Jan 2008 19:56:39 +0100

SMI Query Series - Database Size

The sysmaster interface (SMI) presents a comfortable way to extract information about various parts of your running IDS instance. This information can be used for:

ad hoc analysis of performance problems
determining the status of several IDS sub components
monitoring replication metrics
sampling data for capacity planning purposes
tracking system usage of individual sessions
and many more...

The below SMI query is the second one of a new SMI query series at The Informix Zone. The queries show you how to extract valuable information from the sysmaster database.

smi_db_size.sql

The purpose of this SMI query is to display the individual sizes of all databases in your IDS instance .

The smi_db_size.sql comes in two versions. Choose the one that fits your current IDS version. The purpose of the substrings (stn.dbsname[1,35] is only to make sure that the retrieved row is displayed on a single line within the dbaccess utility. You can remove it if you need the full database name.

IDS < 10

DATABASE sysmaster;
SELECT stn.dbsname db_name,
   SUM
   (
      sti.ti_npused *
      (
         select sh_pagesize from sysshmvals
      )/1024/1024
   ) mb_used,
   SUM
   (
      sti.ti_nptotal *
      (
         select sh_pagesize from sysshmvals
      )/1024/1024
    ) mb_total
FROM systabnames stn, systabinfo sti, sysdatabases sdb
WHERE stn.partnum = sti.ti_partnum
AND   stn.dbsname = sdb.name
GROUP BY 1
ORDER BY 1;

IDS >= 10

DATABASE sysmaster;
SELECT stn.dbsname[1,35] db_name,
   SUM
   (
      sti.ti_npused *
      (
         select pagesize
            from  sysdbspaces
            where name = dbinfo('dbspace', sti.ti_partnum)
      )/1024/1024
   ) mb_used,
   SUM
   (
      sti.ti_nptotal *
      (
         select pagesize
            from  sysdbspaces
            where name = dbinfo('dbspace', sti.ti_partnum)
      )/1024/1024
    ) mb_total
FROM systabnames stn, systabinfo sti, sysdatabases sdb
WHERE stn.partnum = sti.ti_partnum
AND   stn.dbsname = sdb.name
GROUP BY 1
ORDER BY 1;

SMI Query Series - Sequential Scans on Tables

eherber — Sat, 05 Jan 2008 17:16:43 +0100

SMI Query Series - Sequential Scans on Tables

The sysmaster interface (SMI) presents a comfortable way to extract information about various parts of your running IDS instance. This information can be used for:

ad hoc analysis of performance problems
determining the status of several IDS sub components
monitoring replication metrics
sampling data for capacity planning purposes
tracking system usage of individual sessions
and many more...

The below SMI query is the first one of a new SMI query series at The Informix Zone. The queries show you how to extract valuable information from the sysmaster database.

smi_seq_scans.sql

The purpose of this SMI query is to display sequential scans on tables. Sequential scans are not always a bad thing, but they may hurt performance if they occur frequently on tables that contain more than a few hundred rows. An update statistics or the creation of a missing index (plus update statistics if you are not already on IDS 11) on the respective table should normally help in such situations.

The smi_seq_scans.sql comes in two versions. Choose the one that fits your current IDS version. You may swap the two columns in the ORDER BY clause to sort the result set by the number of sequential scans instead of the table size. The purpose of the substrings (stn.dbsname[1,15] and stn.tabname[1,20]) is only to make sure that the retrieved row is displayed on a single line within the dbaccess utility. You can remove it if you need the full database and table names.

You might also reset the statistics profile (onstat -z) before executing the query. Executing the query several times after the reset of the statistics shows you how many sequential scans occurred in this period.

IDS < 10

DATABASE sysmaster;
SELECT 
   stn.dbsname[1,15], 
   stn.tabname[1,18], 
   sti.ti_nptotal *
   (
      select sh_pagesize from sysshmvals
   )/1024/1024 mb_total,
   sti.ti_nrows, 
   spp.seqscans
FROM  systabnames stn, systabinfo sti, sysptprof spp
WHERE stn.partnum = sti.ti_partnum
AND   stn.partnum = spp.partnum
AND   spp.seqscans > 0
ORDER BY mb_total DESC, spp.seqscans DESC;

IDS >= 10

DATABASE sysmaster;
SELECT
   stn.dbsname[1,15],
   stn.tabname[1,18],
   sti.ti_nptotal *
   (
      select pagesize
         from  sysdbspaces
         where name = dbinfo('dbspace', sti.ti_partnum)
   )/1024/1024 mb_total,
   sti.ti_nrows,
   spp.seqscans
FROM  systabnames stn, systabinfo sti, sysptprof spp
WHERE stn.partnum = sti.ti_partnum
AND   stn.partnum = spp.partnum
AND   spp.seqscans > 0
ORDER BY mb_total DESC, spp.seqscans DESC;