maria-developers team mailing list archive
Mailing list archive
Re: GSoC 2016:Unique indexes for blobs
On Mar 03, Shubham Barai wrote:
> I am interested in the project "Unique indexes for blobs".I have read the
> description of the project given on the link
> I want to know what exactly is the task for this project.Any help
> would be greatly appreciated
See storage/myisam/mi_create.c. You see that a myisam table can have
keys (defined in MI_KEYDEF structure) and so-called "uniques" (defined
Keys have length limitation, keys can be unique (HA_NOSAME flag) or not
"uniques" have no length limitation.
When one creates a unique key from SQL:
CREATE TABLE ... (... UNIQUE KEY (...) ... )
this will always create a key (MI_KEYDEF) in a MyISAM table. That's why
unique constraints in MyISAM have a limited length.
This task is about creating MI_UNIQUEDEF "uniques" instead of MI_KEYDEF
"keys" for long unique constraints.
Chief Architect MariaDB