Help Center/ GaussDB(DWS)/ Tool Guide/ DSC/ Using DSC/ Migration Process/ Prerequisites

Updated on 2024-07-19 GMT+08:00

View PDF

Prerequisites

Executing Custom DB Scripts

Custom scripts are executed to support input keywords that do not exist in certain versions of the target database. These scripts must be executed in each target database before the migration.

Table 1 describes the custom scripts in the DSC/scripts/ directory. For details about how to execute custom scripts, see Custom DB Script Configuration.

**Table 1** Custom DB scripts
Script	Description
mig_fn_get_datatype_short_name.sql	Custom DB script for Teradata functions
mig_fn_castasint.sql	Custom DB script for migration of CAST AS INTEGER
vw_td_dbc_tables.sql	Custom DB script for migration of DBC.TABLES
vw_td_dbc_indices.sql	Custom DB script for migration of DBC.INDICES

Follow the steps to execute custom DB scripts:

Use any of the following methods to execute the required scripts in all target databases for which migration is to be performed:

Use gsql.

Use gsql to connect to the target database and paste all content in the SQL file to gsql, which will automatically execute the pasted contents.

Run the following command to connect to the database:

         
              gsql -h <host_addr_xxx.xxx.xxx.xxx> -d <database_name> -U <user_name> -W <password> -p <port_number> -r

Use gsql to connect to the target database and execute a SQL file.

Run the following command to connect to the database and run the SQL file:

         
              gsql -h <host_addr_xxx.xxx.xxx.xxx> -d <database_name> -U <user_name>  -W <password>  -p <port_number> -f <filename.sql> -o <output_filename> -L <log_filename.log>  -r

Use Data Studio.
Use Data Studio to connect to the target database, and then open and run the SQL file in Data Studio.

Custom DB Script Configuration

Custom scripts are SQL files used to migrate from Teradata/Oracle the input keywords that do not exist in the target database.

These scripts must be executed in each target database before the migration.

Open the scripts folder in the release package. Table 2 lists the folders and files in the scripts folder.

The SQL files contain the scripts for the custom migration functions. The GaussDB(DWS) database needs to use these functions to support specific features of Teradata.

**Table 2** Custom DB scripts for DSC
Folder	Script File	Description
-- scripts	-	Folder: all scripts
------ teradata	-	Folder: Teradata functions and scripts
-------- view	-	Folder: scripts to configure views
-	vw_td_dbc_tables.sql	Script: used to enable migration of Teradata DBC.TABLES
-	vw_td_dbc_indices.sql	Script: used to enable migration of Teradata DBC.INDICES
-------- function	-	Folder: scripts to configure Teradata system functions
-X	mig_fn_get_datatype_short_name.sql	Script: used to enable migration of Teradata DBC.COLUMNS
-	mig_fn_castasint.sql	Script: used to enable migration of CAST AS INTEGER
--------db_scripts	-	Folder: scripts to enable Teradata custom functions
-	mig_fn_get_datatype_short_name.sql	Script: used to enable migration of Teradata DBC.COLUMNS
--------core	-	Folder: Teradata core scripts
-	teradatacore.pm	Script: used to perform Perl migration

Configuring DSC and Migration Properties

To configure DSC, configure parameters in the configuration files in the config folder of DSC. Table 3 describes the parameters.

Table 3 Parameters for configuring DSC

Migration

Configuration File

Parameter

Teradata SQL Migration

DSC: application.properties
Teradata SQL Configuration: features-teradata.properties

         
              deleteToTruncate=True/False
distributeByHash=one/many
extendedGroupByClause=True/False
inToExists=True/False
rowstoreToColumnstore=True/False
session_mode=Teradata/ANSI
tdMigrateDollar=True/False
tdMigrateALIAS=True/False
tdMigrateNULLIFZero=True/False
tdMigrateZEROIFNULL=True/False
volatile=local temporary/unlogged

Teradata Perl Migration

DSC: application.properties
Teradata Perl Configuration: perl-migration.properties

         
              add-timing-on=True/False
db-bteq-tag-name=bteq
db-tdsql-tag-name=sql_lang
logging-level=error/warning/info
migrate-variables=True/False
remove-intermediate-files=True/False
target_files=overwrite/cancel
migrate-executequery=True/False

MySQL SQL Migration

DSC: application.properties
MySQL Configuration: features-mysql.properties

         
              table.databaseAsSchema=true
table.defaultSchema=public
table.schema=
table.orientation=ROW
table.type=HASH
table.partition-key.choose.strategy=partitionKeyChooserStrategy
table.partition-key.name=
table.compress.mode=NOCOMPRESS
table.compress.level=0
table.compress.row=NO
table.compress.column=LOW
table.database.template=template0
table.index.rename=false
table.database.onlyFullGroupBy=true
table.database.realAsFloat=false