DB fields suggestion

[morfies]

Hi, thanks very much for your project.
Here I would like to add two small suggestions about the sql:

• I see that some fields are using mysql keywords/reserved words, such as status, owner, name, context.
• And also DECIMAL that does not lose precision is preferred over FLOAT, DOUBLE precision-loss types, current usage of these fields seem all fine though.
• id fields maybe can consider bigint unsigned

[hyj1991]

• And also DECIMAL that does not lose precision is preferred over FLOAT, DOUBLE precision-loss types, current usage of these fields seem all fine though.
• id fields maybe can consider bigint unsigned

PR is welcom :)