All merge/delete statements are executed as SQL commands. That's convenient for action review and such scripts can be saved for later use. But large scripts (for example for huge blob values) can produce some issues. Application may fail with out-of-memory or it may exceed some limitations on the database engine. Even if the database engine provides an API to handle such blobs as stream, this API is not used by the application.
Failure can be caused by different reasons, for example foreign key constraints of some other dependencies. Please check the execution log.
Application settings and diff profiles are saved as regular XML files. Before saving, the application does not check if any other changes could be made by any other application instance and can overwrite these changes.
When you merge table definition, the application produces only table definition changes, it does not merge the data. Data needs to be merged separately if needed.
As a GUI application, it has most actions designed to be performed using a mouse. Application has some keyboard shortcuts, complex dialogs were adjusted to have expected tab order, but there was no comprehensive keyboard usability testing.
Application has online documentation, but it corresponds only to the latest application version. Sometimes documentation can be updated with delay. For our small dev team it is hard to support versioned documentation. However, the application is designed to support offline documentation and if you're a Standard active free-upgrades client then you may contact Support to get instructions to set up offline documentation.
Application updates can be safely installed over the previous version, even with some gaps in the version sequence (for example install v 1.5.4 over 1.2.2). Any non-backward-compatible behavior changes are listed in the release notes. But the application is not designed to be downgradable. In most cases rollback to the previous version does not cause any issues. But in rare cases newer application settings may have some items which are not supported by previous versions and this may cause application crashes in case of rollback. In such cases application settings need to be deleted and for the Standard version license key should be entered again.
Application is using some space in the user profile. It caches large strings, binary values and generated scripts. These temporary files are removed when no longer needed.
If some object type or property is not presented on UI then most likely it is not supported. Example of unsupported object type is table space, example of unsupported object property are table partition options. Information about such objects and properties is not read from database metadata, not shown anywhere and can not be compared or synchronized. See How it works - Schema to get more information about which object types and properties are handled.
Application does not take into account the DEFINER attribute for functions, stored procedures, triggers and events. In some cases this can be convenient because when we compare databases from different servers, these servers may have different users, and the application would report undesired changes if anything except DEFINER is the same.
Application is using a sort-merge join algorithm to compare data in the regular tables with a common primary key ("common" means defined on the same columns with same data types). It requests data from both databases sorted by key, reads record by record and then compares these keys on the application side, expecting that comparison logic is the same on the application side and on both databases. This allows it to process huge amounts of data without significant memory impact on the application side. But that same-comparison-logic assumption is correct only for data types with a natural sort order, like numbers or dates. Particularly, this assumption can be wrong for some string collations. If database collations are different, or if application string comparison logic is other than database collation, then such cases can produce false-positive changes. If you think you face this issue, and if you use a Standard version - then you may try to use Query result diff to get better diff results. Query result diff does all sorting on the application side, which means that comparison logic will be the same for all steps of sort-merge join. But this approach has some limitations: it can't be used for large amounts of data and changes identified by Query result diff can not be merged.
Last updated: 2023-10-03
