In MariaDB the type JSON is an alias for LONGTEXT COLLATE utf8mb4_bin.
When I change the collation of a table containing a JSON column to utf8mb4_unicode_520_ci via
ALTER TABLE table CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci;
will that change the collation of the JSON column as well?
If so: Does that pose a problem for the usability of said JSON column?
will that change the collation of the JSON column as well?
Yes it will.
If so: Does that pose a problem for the usability of said JSON column?
Some problems that I can think off:
The collation change itself does not affect whether the JSON data remains valid, but impacts how string comparisons within JSON queries work. Queries that rely on case-sensitive or binary comparisons might produce different results after the collation change.
Using utf8mb4_unicode_520_ci, comparisons become case-insensitive which might differ from the behavior of utf8mb4_bin where comparisons are case-sensitive.
Using utf8mb4_unicode_520_ci might impact performance, especially for complex queries with string operations.
My suggestion.
Revert json column back to LONGTEXT CHARACTER SET utf8mb4 COLLATE utf8mb4_bin
ALTER TABLE myTable
MODIFY COLUMN json_data LONGTEXT CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;