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Message Posted: Wed, 30 Mar 2011 @ 22:10:05 GMT

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Just to clarify, in 13.10 one can compress on VARCHAR and it appears Null is compressible even on TIMESTAMP columns, but value compression is not. I've validated the null compression on timestamps.

Below are excerpts from 13.10 TD documentation. Unfortunately neither the inclusion list nor exclusion list explicitly address timestamp.

From 13.10 "Database Design"....

You can perform multi-value compression only for the following types of data:

* Nulls
* Zeros
* Blanks
* Constants having any of the following data types.
* BYTE (up to 510 bytes)
* BYTEINT (up to 510 bytes)
* CHARACTER (up to 510 characters)
* DATE (expressed as COMPRESS (DATE 'yyyy-mm-dd'))
* DECIMAL/NUMERIC
* DOUBLE PRECISION
* FLOAT
* GRAPHIC (up to 510 characters)
* INTEGER
* REAL
* SMALLINT
* VARCHAR
* VARGRAPHIC

Page 46 of "SQL Data Definition Language - Detailed Topics"

Multi-value compression is not supported for volatile tables or for the following types of columns:

* Identity
* LONG VARCHAR
* BLOB
* CLOB

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