# Limitations and considerations

When defining a task with Confluent Cloud as the target endpoint, the following limitations apply:

* The Confluent Cloud target endpoint does not support unlimited LOB size. Therefore, when replicating from source tables with LOB columns, *do not* select the Allow unlimited LOB size option.

  For more information on defining LOB settings, see [Target metadata](https://help.qlik.com/en-US/replicate/May2026/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/target_metadata.htm).

* Batch optimized apply mode is not supported. If this mode is set, the task will automatically switch to Transactional apply mode and a message will be written to the task's log file.

  For more information on these modes, see [Change Processing Tuning](https://help.qlik.com/en-US/replicate/May2026/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/tasks_applychangtunestab.htm).

* Store Changes mode is not supported.

  For more information on Store Changes mode, see [Adding tasks](https://help.qlik.com/en-US/replicate/May2026/Content/Global_Common/Content/SharedEMReplicate/Design%20Tasks/tasks_setup.htm).

* The [Ignore ALTER](https://help.qlik.com/en-US/replicate/May2026/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/tasks_applychangsetstab.htm#ignore_alter) Apply Changes setting is not supported for changes to source data types and table renaming.

* Column names must begin with [A-Za-z\_] (letters or an underscore) followed by [A-Za-z0-9\_] (letters, digits, or an underscore). For example, \_Test\_ is a valid column name whereas &Test is not.

  If a source column name does not adhere to this rule, then [a transformation should be used](https://help.qlik.com/en-US/replicate/May2026/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/tasks_useTransTable.htm) to rename the column.

* The [Drop and Create table](https://help.qlik.com/en-US/replicate/May2026/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/tasks_fullLoadSetstab.htm) Target Table Preparation option is not supported
* The [Truncate before loading](https://help.qlik.com/en-US/replicate/May2026/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/tasks_fullLoadSetstab.htm) Target Table Preparation option is not supported
* The Change Data Partitioning [Control table](https://help.qlik.com/en-US/replicate/May2026/Content/Replicate/Main/Control%20Tables/control_tables.htm) is not supported
* DDL Changes: Dropping or renaming a table is not supported