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IBM Cognos Analytics Platform => Cognos Analytics => Administration and Security => Topic started by: sdf on 14 Sep 2018 11:12:16 AM

Title: Data server connections Load Metadata
Post by: sdf on 14 Sep 2018 11:12:16 AM
Hi,

Can anyone shed some light..
Is it required to "Load Metadata"?
Under Data server connections> select connection>properties>schemas

Title: Re: Data server connections Load Metadata
Post by: bus_pass_man on 14 Sep 2018 01:01:47 PM
No it isn't required, but if you want to see anything which is in a particular schema and make use of it you'd need to load the schema.
Title: Re: Data server connections Load Metadata
Post by: sdf on 14 Sep 2018 03:12:14 PM
I guess, it is required if we are creating data module from it.
Which leads me to another question.
When we load schema metadata, where is it stored? in the \data directory or content store?
Are there any limit on the number of schema metadata we can load?
Is there a memory issue if say we have hundreds of schema?
I noticed a spike in cpu memory when loading a metadata. I'm sure this is because, the actual loading are sql select statements on the selected tables and views. I am worried since we have lots of schema deployed.
Title: Re: Data server connections Load Metadata
Post by: the6campbells on 15 Sep 2018 11:23:49 AM
When we load schema metadata, where is it stored? in the \data directory or content store?
ANSWER> In CM

Are there any limit on the number of schema metadata we can load?
ANSWER> No hard limit

Is there a memory issue if say we have hundreds of schema?
ANSWER> Just as with an FM model, don't import clutter that will never be used. Waste of time/resources.

I noticed a spike in cpu memory when loading a metadata. I'm sure this is because, the actual loading are sql select statements on the selected tables and views. I am worried since we have lots of schema deployed.
ANSWER> Set the load options to not "sample" the tables as the schema is introspected.
Title: Re: Data server connections Load Metadata
Post by: sdf on 17 Sep 2018 08:12:52 AM
Thank you very much for the info. I appreciate it.

QuoteI noticed a spike in cpu memory when loading a metadata. I'm sure this is because, the actual loading are sql select statements on the selected tables and views. I am worried since we have lots of schema deployed.
ANSWER> Set the load options to not "sample" the tables as the schema is introspected.

Can you explain what this Retrieve sample data do? How does this affect the data presented when we run reports/dashboard using a datamodule with this setting?

I can't find any documentation that would explain this setting.

Thanks again!
sdf
Title: Re: Data server connections Load Metadata
Post by: the6campbells on 19 Sep 2018 07:00:09 PM
Inference of the role/properties of a column are derived from the data type and column name

By issuing a basic query and looking at the values in the first-N rows of the result set, further inference of some "metadata" can be inferred.

Can help things like join advisor, intent based modelling.

But often, you are not loosing much if you simply import schemata and do no "sample" data.
Title: Re: Data server connections Load Metadata
Post by: sdf on 20 Sep 2018 08:15:04 AM
that made sense..

thanks a lot for the info!

cheers!
sdf