Processing Data¶
DRS processes synchronized objects and allows you to add rules for selected objects.
Filtering Data¶
After a data filtering rule is added, update the source database to ensure data consistency. For example:
The filter criteria are met after the update. You need to continue the synchronization and perform the same update operation on the destination database. If no data is matched, the operation will be ignored, causing data inconsistency.
The filter criteria are not met after the update. You need to continue the synchronization and perform the same update operation on the destination database.
In the Object area of the Data filtering page, select the table to be processed.
In the Filtering Criteria area, enter the filter criteria (only the part after WHERE in the SQL statement, for example, id=1), and click Verify.
Note
Each table has only one verification rule.
Up to 500 tables can be filtered at a time.
The filter expression cannot use the package, function, variable, or constant of a specific DB engine. It must comply with the general SQL standard. Enter the part following WHERE in the SQL statement (excluding WHERE and semicolons), for example, sid > 3 and sname like "G %". A maximum of 512 characters are allowed.
In SQL statements for setting filter criteria, keywords must be enclosed in backquotes, and the value of datatime (including date and time) must be enclosed in single quotation marks, for example, `update` > '2022-07-13 00:00:00' and age >10.
Filter criteria cannot be configured for large objects, such as CLOB, BLOB, and BYTEA.
You are not advised to set filter criteria for fields of approximate numeric types, such as FLOAT, DECIMAL, and DOUBLE.
Do not use fields containing special characters as a filter condition.
You are not advised to use non-idempotent expressions or functions as data processing conditions, such as SYSTIMESTAMP and SYSDATE, because the returned result may be different each time the function is called.
After the verification is successful, click Generate Processing Rule. The rule is displayed.
Click Next.
Advanced Settings for Data Filtering¶
If you need to query an association table, you can use the advanced settings of data processing.
In the Object area of the Data filtering page, select the table to be processed.
In the Filtering Criteria area, specify the filtering criteria, for example, id1 in (select id from db1.tab1 where id >=3 and id <10), and click Verify.
Note
Each table has only one verification rule.
Up to 500 tables can be filtered at a time.
The filter expression cannot use the package, function, variable, or constant of a specific DB engine. It must comply with the general SQL standard. Enter the part following WHERE in the SQL statement (excluding WHERE and semicolons), for example, sid > 3 and sname like "G %". A maximum of 512 characters are allowed.
Filter criteria cannot be configured for large objects, such as CLOB, BLOB, and BYTEA.
You are not advised to set filter criteria for fields of approximate numeric types, such as FLOAT, DECIMAL, and DOUBLE.
Do not use fields containing special characters as a filter condition.
You are not advised to use non-idempotent expressions or functions as data processing conditions, such as SYSTIMESTAMP and SYSDATE, because the returned result may be different each time the function is called.
After the verification is successful, click Generate Processing Rule. The rule is displayed.
In the Advanced Settings area, specify the configuration condition and rule for the association table to help you filter data.
In the Configuration Condition area, enter the association table information entered in 2.
Database Name, Table Name, Column Name, Primary Key, Index, and Filter Criteria are mandatory. If the table does not have an index, enter its primary key.
Filter Criteria is the filter condition of the association table information entered in 2.
Then, click Verify.
After the verification is successful, click Generate Configuration Rule. The rule is displayed in the Configuration Rule area.
To filter data in multiple association tables, repeat 4.
Note
Configuration rules can be deleted.
Click Next.
Viewing Data Filtering Results¶
In the task list, click the task to be processed.
Click the Process Data tab to view data filtering records. Click
in the upper right corner to refresh the record list.