Update Stats tips

[kalpanapai]

Hi

I have a small database with around 80 tables , and cron job is running to do
update stats "update statistics high " runs every night on database and on sysutils ,
we do have lot of data going to database for few tableseveryday . The biggest table has 500000 rows.


Is this update stats is fine or do i have to run individual stats for each table.

At the moment we do not have any performance problems so left as it is , which was set by previous DBA.

And also do i have to run update stats for procedures , sysmaster and sysutils also with the database.
Please advice me , as i am setting up a new server for production , so that i can test it since i am new to Informix database,
any suggestions would be great help for me.

Regards
Kalpana

 

[mynwo]

Hi Kalpana,

Update statistics high updates the statistics for all the rows in you tables. If you are not facing any perforamance issues then its ok, otherwise you can run update statistics only for highly volatile tables.

eg. update statistics high for tablename

You can refer to below links for more info

http://www7b.boulder.ibm.com/dmdd/zones/informix/library/techarticle/miller/0203miller.html#section3

http://www-3.ibm.com/software/data/informix/pubs/library/

Regards,

lloyd

 

[hiten1972]

Hi Kalpana/lloyd


Update statistics (Low|Medium|High)

Update low mode , no data distribution is created
low mode updates only the statistics in the
systables,syscolumns and sysindexes system catalog tables.
if a mode is not specified then default low mode is used.

Best I feel used Update statistic (low option)
may be like update statistics for table -> all tables
update statistics for table table_name
update statistics for table table_name (colname)


Regards
Hiten