From MySQL¶

If the source link of a job is the Link to a MySQL Database, configure the source job parameters based on Table 1.

**Table 1** Parameter description¶
Category	Parameter	Description	Example Value
Basic parameters	Use SQL Statement	Whether you can use SQL statements to export data from a relational database	No
	SQL Statement	When Use SQL Statement is set to Yes, enter an SQL statement here. CDM exports data based on the SQL statement.	select id,name from sqoop.user;
	Schema/Tablespace	Name of the schema or tablespace from which data will be extracted. This parameter is displayed when Use SQL Statement is set to No. Click the icon next to the text box to go to the page for selecting a schema or directly enter a schema or tablespace. If the desired schema or tablespace is not displayed, check whether the login account has the permissions required to query metadata. Note The parameter value can contain wildcard characters (``), which is used to export all databases whose names start with a certain prefix or end with a certain suffix. For example: SCHEMA indicates that all databases whose names starting with SCHEMA are exported. SCHEMA indicates that all databases whose names ending with SCHEMA* are exported. *SCHEMA* indicates that all databases whose names containing SCHEMA are exported.	SCHEMA_E
	Table Name	Name of the table from which data will be extracted. This parameter is displayed when Use SQL Statement is set to No. Click the icon next to the text box to go to the page for selecting the table or directly enter a table name. If the desired table is not displayed, confirm that the table exists or that the login account has the permissions required to query metadata. This parameter can be configured as a macro variable of date and time and a path name can contain multiple macro variables. When the macro variable of date and time works with a scheduled job, the incremental data can be synchronized periodically. Note The table name can contain wildcard characters (``), which is used to export all tables whose names start with a certain prefix or end with a certain suffix. The number and types of fields in the tables must be the same. The examples are as follows: table indicates that all tables whose names starting with table are exported. table indicates that all tables whose names ending with table* are exported. *table* indicates that all tables whose names containing table are exported.	table
Advanced attributes	Partition Column	This parameter is displayed when Use SQL Statement is set to No, indicating that a field used to split data during data extraction. CDM splits a job into multiple tasks based on this field and executes the tasks concurrently. Fields with data distributed evenly are used, such as the sequential number field. Click the icon next to the text box to go to the page for selecting a field or directly enter a field.	id
	WHERE Clause	WHERE clause used to specify the data extraction range. This parameter is displayed when Use SQL Statement is set to No. If this parameter is not set, the entire table is extracted. You can set a date macro variable to extract data generated on a specific date.	DS='${dateformat(yyyy-MM-dd,-1,DAY)}'
	Null in Partition Column	Whether the partition column can contain null values	Yes
	Job Split Field	Used to split a job into multiple subjobs for concurrent execution.	`-`
	Minimum value of a split field	Specifies the minimum value of Job Split Field during data extraction.	`-`
	Maximum Split Field Value	Specifies the maximum value of Job Split Field during data extraction.	`-`
	Number of subjobs	Specifies the number of subjobs split from a job based on the data range specified by the minimum and maximum values of Job Split Field.	`-`
	Extract by Partition	When data is exported from a MySQL database, data can be extracted from each partition in the partitioned table. If this function is enabled, you can configure Table Partition to specify specific MySQL table partitions from which data is extracted. This function does not support non-partitioned tables. The database user must have the SELECT permission on the system views dba_tab_partitions and dba_tab_subpartitions.	No

Note

In a migration from MySQL to DWS, the constraints on the incremental data migration function in MySQL Binlog mode are as follows:
1. A single cluster supports only one incremental migration job in MySQL Binlog mode in the current version.
2. In the current version, you are not allowed to delete or update 10,000 data records at a time.
3. Entire DB migration is not supported.
4. Data Definition Language (DDL) operations are not supported.
5. Event migration is not supported.
6. If you set Migrate Incremental Data to Yes, binlog_format in the source MySQL database must be set to ROW.
7. If you set Migrate Incremental Data to Yes and binlog file ID disorder occurs on the source MySQL instance due to cross-machine migration or rebuilding during incremental data migration, incremental data may be lost.
8. If a primary key exists in the destination table and incremental data is generated during the restart of the CDM cluster or full migration, duplicate data may exist in the primary key. As a result, the migration fails.
9. If the destination DWS database is restarted, the migration will fail. In this case, restart the CDM cluster and the migration job.

The recommended MySQL configuration is as follows:

# Enable the bin-log function.
log-bin=mysql-bin
# Row mode
binlog-format=ROW
# gtid mode. The recommended version is 5.6.10 or later.
gtid-mode=ON
enforce_gtid_consistency = ON

last updated: 2024-07-04 00:38