VARBINARY vs NVARCHAR (SQLStore)

[mwjames]

MW defines [0]

page_id        INT          NOT NULL  PRIMARY KEY IDENTITY(0,1),
page_namespace INT          NOT NULL,
page_title     NVARCHAR(255)  NOT NULL,

SMW uses [1]

$wgDBtype == 'postgres' ? 'TEXT' : 'VARBINARY(255)'; // like page_title in MW page table

What are the performance implications NVARCHAR (unicode storage) vs. binary storage (VARBINARY)?

refs #1184

[0] https://github.com/wikimedia/mediawiki/blob/68df6447ff3ec8c9d99469a83492e70e5380aebb/maintenance/mssql/tables.sql#L112-L113
[1] https://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/master/includes/storage/SMW_SQLHelpers.php#L35

[mwjames]

What are the performance implications NVARCHAR (unicode storage) vs. binary storage (VARBINARY)?

Not sure.

Given that NVARCHAR is only used in connection with MSSQL in MediaWiki [0] and we do not support MSSQL it seems discussing such change has not immediate predictable merit without an overwhelming performance benefit and as per above couldn't be quantified therefore closing this issue.

[0] https://github.com/wikimedia/mediawiki/search?p=2&q=NVARCHAR&unscoped_q=NVARCHAR