Starts a cache monitor that collects buffer cache statistics.
IQ UTILITIES { MAIN | PRIVATE } [ INTO ] table-name { START MONITOR ['monitor-options'] | STOP MONITOR } monitor-options { -summary | {-append | -truncate } -bufalloc | -cache | -cache_by_type | -contention | -debug | -file_suffix suffix | -io | -interval seconds | -threads }...
Option | Description |
---|---|
-summary | Displays summary information for
both the main and temp buffer caches. If you do not
specify any monitor options, you receive a summary
report. Usage:monitor_options -summary |
-cache | Displays main or temp buffer cache
activity in detail. Critical fields are Finds, HR%, and
BWaits. Usage:monitor_options -cache |
-cache_by_type | Breaks -cache results down by IQ
page type. (An exception is the Bwaits column, which
shows a total only.) This format is most useful when you
need to supply information to Technical Support. Usage:
monitor_options -cache_by_type |
-file_suffix | Creates a monitor output file named
<dbname>.<connid>-<main_or_temp>-<suffix>.
If you do not specify an optional file extension, the
file extension defaults to .iqmon. Usage:monitor_options -file_suffix {extension} |
-io | Displays main or temp (private)
buffer cache I/O rates and compression ratios during the
specified interval. These counters represent all
activity for the server; the information is not broken
out by device. Usage:monitor_options -io |
-bufalloc | Displays information on the main or
temp buffer allocator, which reserves space in the
buffer cache for objects like sorts, hashes, and
bitmaps. Usage:monitor_options -bufalloc |
-contention | Displays many key buffer cache and
memory manager locks. These lock and mutex counters show
the activity within the buffer cache and heap memory and
how quickly these locks were resolved. Timeout numbers
that exceed 20% indicate a problem. Usage:monitor_options -contention |
-threads | Displays the processing thread
manager counts. Values are server-wide (i.e., it does
not matter whether you select this option for main or
private). Usage:monitor_options -threads |
-interval | Specifies the reporting interval in
seconds. The default is every 60 seconds. The minimum is
every 2 seconds. You can usually get useful results by running the monitor at the default interval during a query or time of day with performance problems. Short intervals may not give meaningful results. Intervals should be proportional to the job time; one minute is generally more than enough. Usage: monitor_options -interval |
-append | -truncate | Append or truncate output to
existing output file. Truncate is the default. Usage:monitor_options -append | -truncate |
-debug | Displays all information available
to the performance monitor, whether or not there is a
standard display mode that covers the same information.
-debug is used mainly to supply information to Technical
Support. Usage:monitor_options -debug |
IQ UTILITIES PRIVATE INTO monitor START MONITOR '-cache -interval 20'
To control the directory placement of monitor output files, set the MONITOR_OUTPUT_DIRECTORY option. If this option is not set, the monitor sends output to the same directory as the database. All monitor output files are used for the duration of the monitor runs. They remain after a monitor run has stopped.
Either declare a temporary table for use in monitoring, or create a permanent dummy table when you create a new database, before creating any multiplex query servers. These solutions avoid DDL changes, so that data stays up on query servers during production runs.
On UNIX-like operating systems, you can watch monitor output as queries are running. For example:
iq utilities main into monitor_tab start monitor “-cache -interval 2 -file_suffix iqmon”sends the output to an ASCII file with the name dbname.conn#-[main|temp]-iqmon. So, for the iqdemo database, the buffer monitor would send the results to iqdemo.2-main-iqmon
dbname.connection#-main-iqmon //for main buffer cache results
dbname.connection#-temp-iqmon //for temp buffer cache results
The prefix dbname.connection# represents your database name and connection number. If you see more than one connection number and are uncertain which is yours, you can run the Catalog stored procedure sa_conn_info. This procedure displays the connection number, user ID, and other information for each active connection to the database. The -file_suffic clause to change the suffix iqmon to a suffix of your choice. Use a text editor to display or print a file. Running the monitor again from the same database and connection number, overwrites the previous results. To save the results of a monitor run, copy the file to another location or use the -append option.