Netezza / PureData – How to add comments on a field

Netezza / PureData Table Documentation Practices
Netezza / PureData Table Documentation Practices

The ‘Comment on Column’ provides the same self-documentation capability as ‘Comment On table’, but drives the capability to the column field level.  This provides an opportunity to describe the purpose, business meaning, and/or source of a field to other developers and users.  The comment code is part of the DDL and can be migrated with the table structure DDL.  The statement can be run independently, or working with Aginity for PureData System for Analytics, they can be run as a group, with the table DDL, using the ‘Execute as a Single Batch (Ctrl+F5) command.

Basic ‘COMMENT ON field’ Syntax

  • The basic syntax to add a comment to add a comment to a column is:

COMMENT ON COLUMN <<Schema.TableName.ColumnName>> IS ‘<<Descriptive Comment>>’;

Example ‘COMMENT ON Field’ Syntax

  • This is example syntax, which would need to be changed and applied to each column field:

COMMENT ON COLUMN time_dim.time_srky IS ‘time_srky is the primary key and is a surrogate key derived from the date business/natural key’;

Related References

Netezza / PureData – How to add comments on a table

Comment On A Netezza / PureData Table
Comment On A Netezza / PureData Table

Using the ‘Comment On’ capabilities of Netezza is an easy way to provide self-documentation within the DDL structure of a table.  This can be very helpful to developers and users, who can see the DDL of the table.  Personally, I think of it as a way to document the purpose and/or business meaning of a table.  This can be especially, when different team may be working with tables. Also, reduce the reliance on developer and/or user memory, or to search for the technical documentation, which may or may not be readily available.

Basic ‘COMMENT ON Table’ Syntax

The basic syntax to add a comment to add a comment to a table is:

COMMENT ON TABLE <<Schema.TableName>> IS ‘<<Descriptive Comment>>’;

Example ‘COMMENT ON Table’ Syntax

COMMENT ON TABLEdate_dim IS ‘Date dimension table, which provides basic calendar date information’;

Related References