Use DBCAT to migrate schemas from an Oracle database to OceanBase Database|V4.2.0| docs|Distributed Database

Use DBCAT to migrate schemas from an Oracle database to OceanBase Database

Last Updated：2023-11-24 02:58:23 Updated

DBCAT is a lightweight command-line tool that provides features such as DDL conversion and schema comparison between databases. This topic describes how to use DBCAT to migrate schemas.

The DBCAT installation package is named in the dbcat-[version number]-SNAPSHOT.tar.gz format. After you download and decompress the installation package, you can directly use it. The executable file is named dbcat.

Notice

DBCAT is a component of OceanBase Migration Service (OMS). You can obtain its installation package from OceanBase Technical Support.

Prepare the installation environment

DBCAT can run only on CentOS, macOS, and Windows operating systems. You must first install JDK 1.8 or later. You can also use OpenJDK. Then, specify the environment variable JAVA_HOME.

Here is an example of how to install OpenJDK in a CentOS operating system:

$sudo yum -y install java-1.8.0-openjdk.x86_64

$which java
/usr/local/java/jdk1.8.0_261/bin/java

echo 'export JAVA_HOME=/usr/local/java/jdk1.8.0_261/' >> ~/.bash_profile
. ~/.bash_profile

Decompress the installation package:

tar zxvf dbcat-1.8.0-SNAPSHOT.tar.gz
cd dbcat-1.8.0-SNAPSHOT/
chmod +x bin/dbcat

$tree -L 3 --filelimit 30
.
├── bin
│   ├── dbcat
│   ├── dbcat.bat
│   └── dbcat-debug
├── conf
│   ├── dbcat.properties
│   └── logback.xml
├── docs
│   ├── README.docx
│   ├── README.md
│   └── README.txt
├── LEGAL.md
├── lib [45 entries exceeds filelimit, not opening dir]
├── LICENSE
├── meta
│   └── README
└── NOTICE

5 directories, 12 files

The following table describes the directories in the installation package.

Directory name	Description
bin	The directory where the executable file is located.
conf	The directory where log files are located.
lib	The directory where the libraries required for running are located.
meta	The directory to which dictionary table data is exported in offline conversion scenarios.
~/output	The directory where the SQL file and report file are located. This directory is generated during the running of DBCAT.

Export schemas from the Oracle database

DBCAT supports online conversion. In other words, DBCAT can directly connect to the source database and export the objects from the database. If you have too many objects (such as 10,000 objects), the export may be slow.

Here is the export command of DBCAT:

bin/dbcat convert -H<host> -P<port> -u<user> -p<password> -D<database> --service-namex<service-name> --service-id <service-id> --from <from> --to <to> --all

You can run the bin/dbcat help convert command to learn more about the command options.

The required options are described as follows:

Option	Has parameters	Description
-H or --host	Y	The IP address of the database server.
-P or --port	Y	The port number of the database server.
-u or --user	Y	The username used to log on to the database.
-t or --tenant	Y	The name of the OceanBase Database tenant.
-c or --cluster	Y	The name of the OceanBase cluster.
-p or --password	Y	The password used to log on to the database.
-D or --database	Y	The name of the source database. If the source database is a DB2 database, the database name and mode name must be different.
--service-id	Y	The service ID for connecting to the Oracle database.
--service-name	Y	The service name for connecting to the Oracle database.
--as-sysdba	N	Specifies to log on to the Oracle database as the sysdba role.
--sys-user	Y	The username for logging on to the sys tenant of the OceanBase cluster.
--sys-password	Y	The password for logging on to the sys tenant of the OceanBase cluster.
--schema	Y	The schema name of the source database. If the source database is not a DB2 database, the schema name is the same as the database name.
--from	Y	The type of the source database.
--to	Y	The type of the destination database.
--all	N	Specifies to export all database objects.

The optional options are as follows:

Option	Has parameters	Description
-f or --file	Y	The output path of the SQL file.
--offline	N	Specifies to use the offline mode.
--target-schema	Y	The mode name of the destination database.
--table	Y	The table to be exported.
--view	Y	The view to be exported.
--trigger	Y	The trigger to be exported.
--synonym	Y	The synonym to be exported.
--sequence	Y	The sequence to be exported.
--function	Y	The function to be exported.
--procedure	Y	The procedure to be exported.
--dblink	Y	The DBLink to be exported.
--type	Y	The type of objects to be exported.
--type-body	Y	The type body of objects to be exported.
--package	Y	The package to be exported.
--package-body	Y	The package body to be exported.
--no-quote	N	Specifies to generate DDL statements without quotation marks.
--no-schema	N	Specifies to generate DDL statements without schema name.
--target-schema	Y	Specifies to use the specified schema name for the generated DDL statements.
--exclude-type	Y	Specifies to exclude the specified type of objects from the export. You can use this option together with the --all option. For example, --all --exclude-type 'TABLE' specifies to exclude the TABLE type.

The following example shows how to migrate the schemas of all objects from the test database of Oracle Database 12c to an Oracle tenant of OceanBase Database V4.0.0.

bin/dbcat convert -H 100.88.xxx.xxx -P 1521 -uxxx -pxxxxxx -D test --service-name xxx --service-id xxx --from oracle12c --to oboracle40 --all

Some notes about this:

You do not need to directly install DBCAT on the database host. Instead, you can install it on a host that can directly connect to the database host.

In the command, the --from and --to options respectively specify the source and destination database types, which must contain the database version number. The following table describes the source and destination databases supported by DBCAT.

Source database	Destination database
TiDB	OBMYSQL
PG	OBMYSQL
SYBASE	OBORACLE
MYSQL	OBMYSQL
ORACLE	OBORACLE
ORACLE	OBMYSQL
DB2 IBM i	OBORACLE
DB2 LUW	OBORACLE
DB2 LUW	OBMYSQL
OBMYSQL	MYSQL
OBORACLE	ORACLE

In the preceding table, OBMYSQL indicates MySQL tenants of OceanBase Database, and OBORACLE indicates Oracle tenants of OceanBase Database.

The following table describes the versions of supported source and destination databases.

Database	Version
TiDB	tidb4 tidb5
PG	pgsql10
SYBASE	sybase15
DB2 IBM i	db2ibmi71
DB2 LUW	db2luw970 db2luw1010 db2luw1050 db2luw111 db2luw115
MYSQL	mysql56 mysql57 mysql</80>
ORACLE	oracle9i oracle10g oracle11g oracle12c oracle18c oracle19c
OBMYSQL	obmysql14x obmysql21x obmysql22x obmysql200 obmysql211 obmysql2210 obmysql2230 obmysql2250 obmysql2271 ~ obmysql2277 obmysql30x obmysql31x obmysql32x obmysql322 obmysql40
OBORACLE	oboracle2220 oboracle2230 oboracle2250 oboracle2270 ~ oboracle2277 oboracle21x oboracle22x oborcle30x oboracle31x oboracle32x oboracle322 oboracle40

The files generated after the command is executed are stored in the output directory under the home directory.

$tree ~/output/dbcat-20xx-xx-xx-164533/
/home/qing.meiq/output/dbcat-20xx-xx-xx-164533/
├── tpccdb
│   └── TABLE-schema.sql
└── tpccdb-conversion.html

1 directory, 2 files

Import the data to the OceanBase database

The file of data exported by using DBCAT is an SQL file. Here you can use the import function of OceanBase Developer Center (ODC) to import the schemas to the OceanBase database. For more information, see Batch export and import.

You can also use the source command to import data from the SQL file into the OceanBase database. Here is an example:

obclient [test]> source TABLE-schema.sql
Query OK, 0 rows affected (0.044 sec)

Notice

If the SQL file is not in the current directory, the absolute path of the SQL file is required.

Verify the data import result

Example: View the schema of a table in the Oracle database and OceanBase database.

View the schema of the bmsql_customer table in the source Oracle database.

SQL> desc bmsql_customer;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 C_W_ID                                    NOT NULL NUMBER(38)
 C_D_ID                                    NOT NULL NUMBER(38)
 C_ID                                      NOT NULL NUMBER(38)
 C_DISCOUNT                                         NUMBER(4,4)
 C_CREDIT                                           CHAR(2)
 C_LAST                                             VARCHAR2(16)
 C_FIRST                                            VARCHAR2(16)
 C_CREDIT_LIM                                       NUMBER(12,2)
 C_BALANCE                                          NUMBER(12,2)
 C_YTD_PAYMENT                                      NUMBER(12,2)
 C_PAYMENT_CNT                                      NUMBER(38)
 C_DELIVERY_CNT                                     NUMBER(38)
 C_STREET_1                                         VARCHAR2(20)
 C_STREET_2                                         VARCHAR2(20)
 C_CITY                                             VARCHAR2(20)
 C_STATE                                            CHAR(2)
 C_ZIP                                              CHAR(9)
 C_PHONE                                            CHAR(16)
 C_SINCE                                            TIMESTAMP(6)
 C_MIDDLE                                           CHAR(2)
 C_DATA                                             VARCHAR2(500)

View the schema of the bmsql_customer table in the destination OceanBase database.

obclient [SYS]> desc bmsql_customer;
+----------------+---------------+------+-----+---------+-------+
| FIELD          | TYPE          | NULL | KEY | DEFAULT | EXTRA |
+----------------+---------------+------+-----+---------+-------+
| C_W_ID         | NUMBER(38)    | NO   | PRI | NULL    | NULL  |
| C_D_ID         | NUMBER(38)    | NO   | PRI | NULL    | NULL  |
| C_ID           | NUMBER(38)    | NO   | PRI | NULL    | NULL  |
| C_DISCOUNT     | NUMBER(4,4)   | YES  | NULL | NULL    | NULL  |
| C_CREDIT       | CHAR(2)       | YES  | NULL | NULL    | NULL  |
| C_LAST         | VARCHAR2(16)  | YES  | NULL | NULL    | NULL  |
| C_FIRST        | VARCHAR2(16)  | YES  | NULL | NULL    | NULL  |
| C_CREDIT_LIM   | NUMBER(12,2)  | YES  | NULL | NULL    | NULL  |
| C_BALANCE      | NUMBER(12,2)  | YES  | NULL | NULL    | NULL  |
| C_YTD_PAYMENT  | NUMBER(12,2)  | YES  | NULL | NULL    | NULL  |
| C_PAYMENT_CNT  | NUMBER(38)    | YES  | NULL | NULL    | NULL  |
| C_DELIVERY_CNT | NUMBER(38)    | YES  | NULL | NULL    | NULL  |
| C_STREET_1     | VARCHAR2(20)  | YES  | NULL | NULL    | NULL  |
| C_STREET_2     | VARCHAR2(20)  | YES  | NULL | NULL    | NULL  |
| C_CITY         | VARCHAR2(20)  | YES  | NULL | NULL    | NULL  |
| C_STATE        | CHAR(2)       | YES  | NULL | NULL    | NULL  |
| C_ZIP          | CHAR(9)       | YES  | NULL | NULL    | NULL  |
| C_PHONE        | CHAR(16)      | YES  | NULL | NULL    | NULL  |
| C_SINCE        | TIMESTAMP(6)  | YES  | NULL | sysdate | NULL  |
| C_MIDDLE       | CHAR(2)       | YES  | NULL | NULL    | NULL  |
| C_DATA         | VARCHAR2(500) | YES  | NULL | NULL    | NULL  |
+----------------+---------------+------+-----+---------+-------+
21 rows in set (0.002 sec)

The schema of the bmsql_customer table is consistent in the source and destination databases.