15.10 - Example: Specifying Different MERGEBLOCKRATIOs - Teradata Database

Teradata Database SQL Data Definition Language Syntax and Examples

prodname
Teradata Database
vrm_release
15.10
created_date
December 2015
category
Programming Reference
featnum
B035-1144-151K

These examples demonstrate different specifications for the MERGEBLOCKRATIO option. If the DBS Control parameter DisableMergeBlocks is set to TRUE, Teradata Database ignores the setting for this option globally and disables all data block merges for all tables in the system. See Utilities, B035-1102 for details.

The first example defines emp_table in such a way that Teradata Database uses the value for the DBS Control parameter MergeBlockRatio as the merge block ratio whenever it merges data blocks for the table.

     CREATE TABLE emp_table, DEFAULT MERGEBLOCKRATIO (
     emp_no INTEGER);

The second example sets the value of the merge block ratio for emp_table to 25%.

     CREATE TABLE emp_table, MERGEBLOCKRATIO=25 PERCENT (
     emp_no INTEGER);

The last example defines emp_table in a way that disables all data block merges.

     CREATE TABLE emp_table, NO MERGEBLOCKRATIO (
     emp_no INTEGER);