Netezza / PureData – List of Views against a table

PureData Powered by Netezza
PureData Powered by Netezza

I have found myself using this simple, but useful SQL time in recent weeks to research different issues and to help with impact analysis.  So, I thought I would post it while I’m thinking about it.  It just gives a list of views using a table, which can be handy to know.  This SQL is simple and could be converted to an equi-join.  I used the like statement mostly because I sometimes want to know if there are other views a similar nature in the same family (by naming convention) of tables.

Select All Fields From The _V_View

This is the simplest form of this SQL to views, which a table.

Select * from _v_view

where DEFINITION like ‘%<<TABLE_NAME>>%’ ;

Select Minimal Fields From The _V_View

This is the version of the SQL, which I normally use, to list the views, which use a table.

Select VIEWNAME, OWNER from _v_view

where DEFINITION like ‘%<<TABLE_NAME>>%’;

Related References

Netezza / Puredata – How to replace or trim CHAR(0) is NULL characters in a field

PureData Powered by Netezza
PureData Powered by Netezza

Occasionally, one runs into the problem of hidden field values breaking join criteria.  I have had to clean up bad archive and conversion data with hidden characters serval times over the last couple of weeks, so, I thought I might as well capture this note for future use.

I tried the Replace command which is prevalent for Netezza answers to this issue on the web, but my client’s version does not support that command.  So, I needed to use the Translate command instead to accomplish it.  It took a couple of searches of the usual bad actors to find the character causing the issue, which on this day was chr(0).  Here is a quick mockup of the command I used to solve this issue.

Example Select Statement

Here is a quick example select SQL to identify problem rows.

SELECT TRANSLATE(F.BLOGTYPE_CODE, CHR(0), ”) AS BLOGTYPE_CODE, BT.BLOG_TYP_ID, LENGTH(BT.BLOG_TYP_ID) AS LNGTH_BT, LENGTH(F.BLOGTYPE_CODE) AS LNGTH_ BLOGTYPE

FROM  BLOGS_TBL F,  BLOG_TYPES BT WHERE TRANSLATE(F.BLOGTYPE_CODE, CHR(0), ”) =  BT.BLOG_TYP_ID AND LENGTH(BT.BLOG_TYP_ID) <>Length(LENGTH(F.BLOGTYPE_CODE) ;

 

Example Update Statement

Here is a quick shell update statement to remove the Char(0) characters from the problem field.

Update <<Your Table Name>> A

Set A.<<Your Field Name>> = TRANSLATE(A.<<Your FieldName>>, CHR(0), ”)

where length(A.<<Your Field Name>>) <> Length(A.<<Your FieldName>>) And << Additional criteria>>;

 

 

 

Netezza / PureData – How to Substring on a Character

PureData Powered by Netezza
PureData Powered by Netezza

 

I had a reason this week to perform a substring on a character in Netezza this week, something I have not had a need to do before.  The process was not as straightforward as I would have thought, since the command is explained as a static position command, and the IBM documentation, honestly, wasn’t much help.  Knowing full well, that text strings are variable having to provide a static position is not terribly useful in and of itself.  So, we need to use an expression to make the substring command flexible and dynamic.

I did get it work the way I needed, but it took two commands to make it happen:

  • The First was the ’instr’ command to identify the field and character I wanted to substring on: instr(<<FIELD_NAME>>,’~’) as This provides the position number of the tilde (~).
  • The second was the ‘substr’ command in which I embedded the ‘instr’ command: substr(<<FIELD_NAME>>,0,instr(<<FIELD_NAME>>,’~’) )

This worked nicely for what I needed, which was to pick out a file name from the beginning of a string, which was delimited with a tilde (~)

Substring on a Character Command Format

  • This format example starts with position zero (0) as position 1 of substring command and goes to the first tilde (~) as position 2 of the substring command.
Select  <<FIELD_NAME>>

, instr(<>,’~’) as pos2

, substr(<<FIELD_NAME>>,0,instr(<<FIELD_NAME>>,’~’) ) as Results

From <<Table_Name>>

where  <<Where_Clause>>;

 

 

Related references

IBM Knowledge Center, Home, PureData System for Analytics 7.2.1, IBM Netezza database user documentation, Netezza SQL basics, Netezza SQL extensions, Character string functions

IBM Knowledge Center, Home PureData System for Analytics 7.0.3, IBM Netezza Database User’s Guide, Netezza SQL basics, Netezza SQL extensions, Character functions

Netezza / PureData – How To Get A List Of When A Store Procedure Was Last Changed Or Created

Netezza / Puredata - SQL (Structured Query Language)
Netezza / Puredata – SQL (Structured Query Language)

In the continuing journey to track down impacted objects and to determine when the code in a database was last changed or added, here is another quick SQL, which can be used in Aginity Workbench for Netezza to retrieve a list of when Store Procedures were last updated or were created.

SQL List of When A Stored Procedure was Last Changed or Created

select t.database — Database
, t.OWNER — Object Owner
, t.PROCEDURE — Procedure Name
, o.objmodified — The Last Modified Datetime
, o.objcreated — Created Datetime

from _V_OBJECT o
, _v_procedure t
where
o.objid = t.objid
and t.DATABASE = ‘<<Database Name>>
order by o.objmodified Desc, o.objcreated Desc;

 

Related References

 

Netezza / PureData – How To Get a SQL List of When View Was Last Changed or Created

Netezza / PureData SQL (Structured Query Language)
Netezza / PureData SQL (Structured Query Language)

Sometimes it is handy to be able to get a quick list of when a view was changed last.  It could be for any number of reason, but sometimes folks just lose track of when a view was last updated or even need to verify that it hadn’t been changed recently.  So here is a quick SQL, which can be dropped in Aginity Workbench for Netezza to create a list of when a view was created or was update dated last.  Update the Database name in the SQL and run it.

SQL List of When A view was Last Changed or Created

select t.database — Database
, t.OWNER — Object Owner
, t.VIEWNAME — View Name
, o.objmodified — The Last Modified Datetime
, o.objcreated — Created Datetime

from _V_OBJECT o
,_V_VIEW_XDB t
where
o.objid = t.objid
and DATABASE = ‘<<Database Name>>
order by o.objcreated Desc, o.objmodified Desc;

Related References

 

Netezza / PureData – How To Quote a Single Quote in Netezza SQL

How To Quote a Single Quote in Netezza SQL?

The short answer is to use four single quotes (””), which will result in a single quote within the select statement results.

How to Assemble the SQL to Quote a Single Quote in a SQL Select Statement

Knowing how to construct a list to embed in a SQL where clause ‘in’ list or to add to an ETL job can be a serious time saver eliminating the need to manually edit large lists.  In the example below, I used the Select result set to create a rather long list of values, which needed to be included in an ELT where clause.  By:

  • Adding the comma delimiter (‘,’) and a Concatenate (||) on the front
  • Followed by adding a quoted single Quote (entered as four single quotes (””)) and a Concatenate (||)
  • The Field I which to have delaminated and Quoted (S1.ORDER_NUM)
  • And closed with a quoted single Quote (entered as four single quotes (””))

This results in a delimited and quoted list ( ,’116490856′) which needs only to have the parentheses added and the first comma removed, which is much less work than manually editing the 200 item that resulted from this select.

Example SQL:

SELECT Distinct

‘,’||””|| S1.ORDER_NUM||”” as Quoted_Order_Number

FROM Sales S1

How to Quote A Single Quote Example SQL
How to Quote A Single Quote Example SQL

Related Reference

Netezza / PureData – How to build a multi table drop command from a select

Database Management
Database Management

How to Quick Drop Multiple Tables

occasionally, there is a need to quickly drop a list of tables and you don’t always want to write or generate each command individually in Aginity.  So, here is a quick example of how you can use a ‘Select’ SQL statement to generate a list of drop commands for you. Now, this approach assumes there is a common naming convention, so, you may need to adapt it to your needs.

An outline of the Drop Multiple Tables Process

Here is a quick summary of the steps to generate the drop statements from _V_Table:

  1. Build required Netezza SQL select; paying particular attention to the where clause criteria to exclude any unnecessary tables.
  2. Execute the SQL statement
  3. Copy from Aginity Results Tab without headers
  4. Past into new Aginity Query window
  5. validate that only the tables are in the list — No extras
  6. Click with the SQL Drop command list and Execute as a single batch

Example generate the drop statements

select  ‘Drop table ‘||tablename||’;’

from _V_TABLE

where tablename like ‘NZCC_TT_%’;

 

Related References

IBM Knowledge Center > PureData System for Analytics 7.2.1

IBM Netezza database user documentation > Netezza SQL command reference > Drop Table