Load

Owned by Copy Space for Confluence
Jan 22, 2017
2 min read

Dbvisit Replicate can automatically instantiate the data before the replication starts. The Replicate Load functionality works for the following target databases:

  • Oracle
  • SQL Server
  • MySQL

The Replicate Load functionality is completely automatic and ensures that the tables are created on the target before the load begins. It takes care of the different data types between the databases for all supported data types. 

In section 2 of the Setup Wizard there is a question about what data instantiation script to create.  One of the choices available is called 'load'.  The option for load will not create a script. A second question will be asked regarding if you want to keep the table on the target or create it anew.  By choosing this method Replicate will automatically load the data when you start up the MINE process and APPLY process, no export/import or additional scripts are needed. 

The Dbvisit Replicate Load method will not be as fast as native export/import tools.

How does it work

The Dbvisit Replicate Load method uses a select * from table to load the data into a special Plog. These plogs will have the name of the table as part of the plog filename. This plog is then transferred to the target server where it is applied to the target database.

Example

Lock and copy the data initially one-by-one or at a single SCN?
one-by-one : Lock tables one by one and capture SCN
single-scn : One SCN for all tables
ddl-only   : Only DDL script for target objects
resetlogs  : Use SCN from last resetlogs operation (standby activation, rman incomplete recovery)   
(one-by-one/single-scn/ddl-only/resetlogs) [single-scn] 
What data instantiation script to create?
dp_networklink : Data Pump with network link. No export datafile is created (APPLY.sh)
dp_exp         : Data Pump with export datafile. Creates an export datafile (APPLY.sh)
exp            : Pre-datapump exp/imp with export datafile (APPLY.sh)
ddl_file       : DDL file created (APPLY.sql)
ddl_run        : DDL is automatically executed on target
load           : All replicated data is created and loaded automatically 
none           (dp_networklink/dp_exp/exp/ddl_file/ddl_run/load/none) [dp_networklink] load
Do you want to (re-)create the tables on target or keep them (they are already  created)? (create/keep) [keep] create

If there are columns in the tables that contain datatypes that are not currently supported, they will automatically be excluded from that load utility.  You will see warning messages like this:

dbvrep> PREPARE OFFLINE SCHEMA "SCOTT"
Table SCOTT.REPTEST1 instantiated at SCN 20246293
Table SCOTT.REPTEST2 instantiated at SCN 20246293
WARN-9086: Unsupported datatype ROWID found in table SCOTT.TAB7. Do not
forget to exclude the column.
Table SCOTT.TAB7 instantiated at SCN 20246293
WARN-9086: Unsupported datatype XMLTYPE found in table SCOTT.TAB8. Do not
forget to exclude the column.
Table SCOTT.TAB8 instantiated at SCN 20246293