Netezza does not have CLOBs but a VARCHAR can hold up to 64KB.  What are you doing that makes you believe you need a CLOB?

Assuming that your average column name is <= 20 characters, a 64000 byte varchar could hold 64000/20 = 3200 columns.  Even if you repeat them twice that still gives you 1600 columns.  I suspect that the 64000 byte varchar will easily hold the SQL that you want to generate for use with EXECUTE IMMEDIATE.

Hello,

I want to use CLOB or something like CLOB to put the data which is there is a column into a different table since it is of huge size and my table is exceeding the max allowed size if I include it in the original one.

What can I use if netezza does not suport clob, or do I need to do any pre processing? Also is there any alternate method.

Please Advise, thanks.

Saket Kale.

What kind of ddl changes are you looking to detect?  What is an example of how the ddl is being changed?  Quite often in Netezza, ddl is changed with a CTAS.  This is basically creating a new object (which later gets renamed to the original object's name).  That results in a whole new object ID and create timestamp.

You can have either a VARCHAR(64000) or NVARCHAR(16000) column. Their is a total row width limit of 64K bytes.  You are on your own as far as assigning keys between the two tables (use a sequence).  What DB2 is doing (and Oracle has similar options) is a physical implementation for storing large objects that is not supported in Netezza (as they don't support large objects).  So you need to define your own table and manage relationships.

As long as the CLOB data fits and only contains character data, you should be ok.  If you are trying to store binary data (pictures, audio, video, etc...), this will not work because character set encoding may corrupt the contents in the column.  Such BLOBs should be stored externally and referenced via a URL stored in the Netezza table.