betodealmeida commented on pull request #17360: URL: https://github.com/apache/superset/pull/17360#issuecomment-977982298
> > IIRC, there does have some implications on search performance for VARCHAR vs TEXT in MySQL. Search w/ indexing is either not possible or much slower doe TEXT depending on which storage engine you use and which MySQL version you are on. > > Thanks for you input, I appreciate as this is not my expertise, I still need guidance whether or not we should use a VARCHJAR with a higher number or a TEXT for that specific column. Looks like with MySQL we can use still `TEXT`, but we need to specify a length in order to have an index: https://dev.mysql.com/doc/refman/8.0/en/create-index.html#create-index-column-prefixes. So we could change to `TEXT`, and later still add an index if needed. Performance-wise there seems to be an extra cost when operating on `TEXT` (https://dba.stackexchange.com/a/222182), but I think it's safe to assume that we're only going to do simple scans on this table, so it should be fine from what I understand. Since we don't know the maximum expected size of this column I think it's OK to: 1. Switch to `TEXT` 2. If needed in the future add an index prefix, after consulting the community on the size -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
