7.6. What the prechecks examine

Check	What you need to understand
Migration path	Checks that the Source → Target direction is supported.
Source / Target connection	Checks that both servers respond using the configured accounts.
SQL modes	Identifies SQL modes that may not be accepted on the Target.
ENUM / SET	Checks certain size limits that may prevent object creation.
Foreign keys	Identifies, among other things, constraint names that are too long.
Views	Identifies view column names that are incompatible with the Target’s limits.
Partitioning and engine	Searches for combinations that may not be compatible with the Target.
utf8 / utf8mb3	Flags objects that still use this legacy character set.
Collations	Checks that the collations used on the Source exist on the Target or that a known adaptation is possible.
Reserved words	Flags object names that correspond to reserved words on the Target.
DEFINER and stored objects	Helps identify views, routines, or events whose creation context or accounts may cause problems.
GROUP BY with ASC/DESC	Flags older syntax that should be reviewed in stored objects.
Null/partial dates	Identifies date values that may be rejected by the Target’s SQL rules.
ROW_FORMAT InnoDB	Flags older formats that may require adaptation.
max_allowed_packet	Warns if the Target server’s limit may be insufficient for large INSERT statements or BLOBs.
Additional MySQL check	For certain adjacent MySQL version upgrades, SQLmig can use MySQL Shell when it is available.