isolated index scans

[Former Member]

Hi,

on MAX DB 7.8 on Win 2008 some queries fail with

isolated index scans

error message.

Any idea about that.

Thank you.

[thorsten_zielke]

Hi,

please post the complete error message and the exact MaxDB version you are using.

Thorsten

[Former Member]

Thank you.

Version is 7.8.01.16

and the exact error message :

2275 isolated index scan, selectivity 0.08%: 2789481 rows read, 2149 row qualified

We see it in dbacockpit Transaction : /performance/Database Analyzer/Bottlenecks

Regards.

[thorsten_zielke]

Ok, first let me recommend that you upgrade your MaxDB to a recent 7.8.02 version (albeit unrelated to your current question).

Regarding the Database Analyzer message, this is rather a 'warning' than an 'error' message.
It means that you have SQL queries with pretty bad 'selectivity' - this is the rlation between rows returned by the query and the rows the database needed to read to obtain that result.

If you are concerned about this, try to identify the running SQL statements and try to improve them or create a new index, if needed. For identifying the SQL, you can use the 'Command/Resource Monitor' (or - I think - in MaxDB 7.9 only, look at the Database Analyzer 'Running_Commands' file).

Thorsten

[Former Member]

Thank you.

I will try this :

identifying the SQL

create a new index

Regards.