Check Details
1. Check the following parameter values of the source and target databases. If a parameter has different values in the source database and target database, the verification task will report a warning. The warning will not block the migration task but may impact the business. Evaluate and decide whether to modify the parameters.
TimeZone, lc_monetary, lc_numeric, array_nulls, server_encoding, DateStyle, extra_float_digits, gin_fuzzy_search_limit, xmlbinary, and constraint_exclusion.
When parameters are not set consistently, the specific impacts are as follows.
TimeZone: sets the instance time zone. If this parameter has different values, data may be incorrect after migration.
lc_monetary: sets the instance currency mode. If this parameter has different values, currency numbers may be incorrect after migration.
lc_numeric: sets the instance numeric mode. If this parameter has different values, data may be incorrect after migration.
array_nulls: sets whether arrays can be empty. If this parameter has different values, data inconsistency may occur, and some data may fail to be migrated.
server_encoding: sets the instance character set. If this parameter has different values, garbled characters may be present in the stored data.
DateStyle: sets the date format. If this parameter has different values, data migration may fail.
extra_float_digits: sets the output precision of floating-point values. If this parameter has different values, data precision will be affected. In high-precision database use cases, data inconsistency will occur after migration.
gin_fuzzy_search_limit: sets a soft upper limit on the set size returned by the GIN index. If this parameter has different values, data display inconsistency will occur after migration.
xmlbinary: sets the XML function conversion result. If this parameter has different values, function execution in the target database may be different from that in the source database.
constraint_exclusion: sets whether the restraints take effect. If this parameter has different values, data inconsistency may occur after migration.
2. Check whether the character set configurations of the source and target databases are inconsistent. If so, the verification task will report an error. Modify them to ensure consistency.
Fixing Method
1. Use the superuser account to log in to the source database.
2. Run the following sample statements to modify the corresponding parameters:
You can first modify the parameters in the source database. If such parameters cannot be modified, you need to modify them in the target database through Online Support. The server_encoding parameter cannot be modified in the source database. If this parameter is abnormal, check whether it has been created in the target database. If it has been created and is inconsistent with that in the source database, a new instance must be requested. If it has not been created, refer to the following method to modify it (currently, TencentDB instances only support UTF8 and LATIN character sets).
alter system set timezone='parameter value';
alter system set lc_monetary='parameter value';
alter system set lc_numeric='parameter value';