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Re: How to change max key length for MyISAM?
Dnia Thu, Jan 14, 2021 at 08:25:42PM +0100, Sergei Golubchik napisał(a):
> Hi, Witold!
> On Jan 14, Witold Filipczyk wrote:
> > Sorry, for private question, but I did not know where to ask.
> > mariadb-10.3.27.
> > I changed in include/myisam.h:
> > #define MI_MAX_KEY_LENGTH 3072 /* Max length in bytes */
> > but, it did not help, still this ERROR 1071 (42000): Specified key was too long; max key length is 1000 bytes.
> > What more to change to get key length 3072 for MyISAM tables?
> Change HA_MAX_KEY_LENGTH. MI_MAX_KEY_LENGTH is only used for temporary
I'll try. Thanks!
> > And what can be negative impact of such a change?
> More memory on the stack, so if you have a table with lots and lots of
> rows, searching for long keys is more likely to cause overflow the
> stack. Might be slower, perhaps, as it'll need to copy more data.
> It's all "might", may be there will be no negative impact at all.
> Why do you want to increase the max key length?
I like mysqlhotcopy as backup tool, but new soft requires big key.
> VP of MariaDB Server Engineering
> and security@xxxxxxxxxxx