Can the SPECTRUM DDM database size be increased? (Legacy KB ID CNC TS32174 )

Document ID : KB000051930
Last Modified Date : 14/02/2018
Show Technical Document Details
Here are the steps that need to be performed in order to increase the size of the DDM database.  WARNING: Please keep in mind that doing this could cause performance issues if your database becomes too large.  Customers should be warned of this before making these changes.


1.    Log into MySQL and tell it to use the ddmdb


?         %> ./mysql ?uroot ?proot ddmdb


 


2.    Now see what the average row length and current number of rows look like by entering the following command:


?         mysql> show table status like ?event?\G


 


3.    The interesting fields here are "Avg_row_length" and "Max_data_length".  The Max_data_length should be a number like 4294967295 (which is 4 GBs).  Now if you take Max_data_length and divide it by Avg_row_length, you will get the current table capacity (measured in the maximum number of rows that could be supported).


 


4.    To increase the table size, you?ll need to use an alter table command to increase the maximum number of rows (i.e. max_rows) while specifying the avg_row_length.  You want to pick a number that is significantly higher than the maximum number of rows that is currently supported (as determined by our calculation above).  That can be accomplished through a command like this (this could take a while to execute):


?         mysql> alter table event max_rows = <insert value> avg_row_length = <use existing value>;


As an example:


?         mysql> alter table event max_rows = 200000000000 avg_row_length = 57;


 


5.    Use the show table status command to verify that the table has been altered:


?         mysql> show table status like ?event?\G


 

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Related Issues/Questions:
Can the SPECTRUM DDM database size be increased?

Problem Environment:
SPECTRUM 9.0
DDM

Causes of this problem:
Prior to SPECTRUM 9.0 the DDM database size could not be increased.  However, in SPECTRUM 9.0 the database size can be over 4 GB.  If the customer has a new 9.0 install (not upgraded) this functionality should already be available.  But if they've upgraded from SPECTRUM 8.1 or 7.1 SP3 there are some steps that need to be completed.


(Legacy KB ID CNC TS32174 )