MySQL 4 to MySQL 5: PRIMARY & INDEX vs BTREE ?

[Sapphyre]

I imported a DB via PHPMyAdmin and all the PRIMARY KEY and KEY designations which are PRIMARY and INDEX when seen in the "structure" ended up as BTREE in the new DB.

Is this going to cause a problem - do they need to be corrected?

The SQL dump had them spec'd like this:

PRIMARY KEY (clickid),
KEY index_page (page),
KEY index_domain_referrerdomain_date (domain,referrerdomain,date),
KEY channel (channel),
KEY index_year_month_day_hour (year,month,day,hour),
KEY index_keywords_date (keywords,date),
KEY index_ip (ip),
KEY index_referrer (referrer)

or this

PRIMARY KEY (ID),
UNIQUE KEY ID (ID),
KEY ID_2 (ID)

Was imported in PHPMyAdmin with compatibility mode: MYSQL40

[Sapphyre]

Maybe a PHPMyAdmin display bug?
Oddly enough, when exported from the new PHPMyAdmin, the SQL comes out the same for the key specs except for the addition of backticks:

PRIMARY KEY (`ID`),
UNIQUE KEY `ID` (`ID`),
KEY `ID_2` (`ID`)

No mention of BTREE at all here.