[GitHub] john-bodley edited a comment on issue #6777: Revert "Removing uniqueness constraints on tables table"

[GitBox <gi...@apache.org>]

john-bodley edited a comment on issue #6777: Revert "Removing uniqueness constraints on tables table"
URL: https://github.com/apache/incubator-superset/pull/6777#issuecomment-458777315
 
 
   @agrawaldevesh per the comment in my PR, by creating a uniqueness constraint on a tuple of columns the size of the constraint is defined by the combined size of the underlying columns (per [here](https://stackoverflow.com/questions/20014106/how-to-create-this-table-1071-specified-key-was-too-long-max-key-length-is/42497309)). 
   
   Previous the constrain required: 4 (`database_id`) + 250 (`table_name`) * 3 = 754 bytes, whereas now it requires: 4 (`database_id`) + [255 (`schema`) + 250 (`table_name`)] * 3 = 1,519 bytes. In https://github.com/apache/incubator-superset/pull/5449 the column sizes were changed: 4 (`database_id`) + [127 (`schema`) + 127 (`table_name`)] * 3 = 766 bytes.
   
   

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services

---------------------------------------------------------------------
To unsubscribe, e-mail: notifications-unsubscribe@superset.apache.org
For additional commands, e-mail: notifications-help@superset.apache.org