You can update the table structure of your MYSQL PLINKDB as of V8.1.09 to the state of V9.08 SP3 via script.

After executing the script both "old" V8 entries can be read and new entries can be written into the database.

Change steps:

  * 8.1: 
    - add table: PLMTABLE2
    - add table: PLM_HIERARCHY
    - add table: CNSSEQ
  
  * 9.00:
    - add table: TREETABLE
    - add table: CLASSASSIGNTABLE
  
  * 9.01:
    - add index: ELI_INDEX_PRJ_PATH ON LINKTABLE (PRJ_PATH);
    - add index: ETR_INDEX_PRJ_PATH ON TREETABLE (PRJ_PATH);
    
  * 9.02:
    - add table: LOCKTABLE
    - during develoment of 9.02 the LOCKTABLE column 
      SESSION was renamed to SESSIONID
  
  * 9.03 SP3:
    - alter PLMTABLE2.VERSION to be nullable (remove NOT NULL)
  
  * 9.04 SP0:
    - alter LINKTABLE: add VARSET_UPDATE column
    - alter TREETABLE: add LEVEL0-LEVEL9 columns
    
  * 9.07 
    - VARCHAR to NVARCHAR  
    
  * 9.07 SP1
    - alter PLMTABLE2: add CREATIONINFO column

You can find the script on the installation DVD as of PARTsolutions V9.08 SP2 under tools\databases\MYSQL\plinkdb_patch_mysql.sql.