how can I increase the max key length?

Hi,

if I try to install mediawiki, I get following mysql-error, during running
config/index.php: "Specified key was too long; max key length is 1000
bytes". How can I allow keys longer than 1000 bytes? I use mysql-4.1.14
from gentoo-portage.

Best regards
Sebastian Noack

Sebastian Noack wrote:
> Hi,
>
> if I try to install mediawiki, I get following mysql-error, during running
> config/index.php: "Specified key was too long; max key length is 1000
> bytes". How can I allow keys longer than 1000 bytes? I use mysql-4.1.14
> from gentoo-portage.

Use the source, Luke.

Although I'd discourage using keys that long - what's the point? If you
need a key that is longer than 1000 bytes, it takes a lot of time to
figure out if a key matches a condition. If the keys are substrings of
blobs, there is not much point to it anyway. Unless you are storing
text, in which case a fulltext index would be appropriate.

> Although I'd discourage using keys that long - what's the point? If you
> need a key that is longer than 1000 bytes, it takes a lot of time to
> figure out if a key matches a condition. If the keys are substrings of
> blobs, there is not much point to it anyway. Unless you are storing
> text, in which case a fulltext index would be appropriate.

Like I said, I only try to install mediawiki. But I have find out that the
following SQL-Query occurs the error:

CREATE TABLE categorylinks ( cl_from int(8) unsigned NOT NULL default '0',
cl_to varchar(255) binary NOT NULL default '', cl_sortkey varchar(255)
binary NOT NULL default '', cl_timestamp timestamp NOT NULL, UNIQUE KEY
cl_from(cl_from,cl_to), KEY cl_sortkey(cl_to,cl_sortkey(128)), KEY
cl_timestamp(cl_to,cl_timestamp) )

But because I don't have designed the db-structure by my own, I would
prefer to don't alter it. So I ask again, is there a way to increase the
max length for keys?

Best regards
Sebastian Noack

Sebastian Noack wrote:
>>Although I'd discourage using keys that long - what's the point? If you
>>need a key that is longer than 1000 bytes, it takes a lot of time to
>>figure out if a key matches a condition. If the keys are substrings of
>>blobs, there is not much point to it anyway. Unless you are storing
>>text, in which case a fulltext index would be appropriate.
>
>
> Like I said, I only try to install mediawiki. But I have find out that the
> following SQL-Query occurs the error:
>
> CREATE TABLE categorylinks ( cl_from int(8) unsigned NOT NULL default '0',
> cl_to varchar(255) binary NOT NULL default '', cl_sortkey varchar(255)
> binary NOT NULL default '', cl_timestamp timestamp NOT NULL, UNIQUE KEY
> cl_from(cl_from,cl_to), KEY cl_sortkey(cl_to,cl_sortkey(128)), KEY
> cl_timestamp(cl_to,cl_timestamp) )
>
> But because I don't have designed the db-structure by my own, I would
> prefer to don't alter it. So I ask again, is there a way to increase the
> max length for keys?

Do you notice *any* key in this query that's longer than 255+128 = 383
bytes? I don't, but then I'm myopic. Maybe you could post the exact
error message?