What would be the max no of characters we can save in the database by using para

You can use a Text process variable or string cdt element to store values.

Have you specified column definition in CDT as below?
<xsd:appinfo source="appian.jpa">@Column(name="columnName", nullable=true, columndefinition="CLOB)")</xsd:appinfo>

yes, I got it thank you Amit

Hi,
I am able to store it in the database and as well as able to load it in PV from database in the process model. But unable to load this in the tempo dashboard(tried with query rule and as well as record filed)

Any suggestion?