Today, etcdctl endpoint health only performs a quorum GET. If server is corrupted or exceeded quota (which put the server into read only mode), this command incorrectly returns healthy.

Since version 0.16.5, th following code returns a null worksheet:
XLSX.utils.json_to_sheet([], {header: columns})

Is it now working as it is wanted? If so, how could we create an empty worksheet? In my case it is expected that sometimes the data is an empty array. And an empty worksheet only with headers is expected.

Index constraint generation currently supports constraints from LIKE expressions, but the opt statistics code does not. A simple improvement would be to handle the case where the expression is exactly equivalent to a range of values.

Note that such a rule would need to handle escaping correctly (which the index constraints code currently does not, see #44123).

Sometimes it is needed to store compressed data in the DB. Unfortunately not all the DBs have built-in compression and FUSE compressed FSes are not available for every OS. So it may make sense to store compressed binary blobs in the DB.

Unfortunately when one sees them in DBeaver he sees them compressed, but often they are needed uncompressed. So it'd be nice to have a feature to decompress the

必须先将通过STable创建的表先删除，然后才能删除超级表。当级联表很多时就麻烦了，除非写代码来删除。

Issue description

Go 1.15 will introduce a new Validator interface, which may be implemented by Conn to allow drivers to signal if a connection is valid or if it should be discarded:

https://tip.golang.org/pkg/database/sql/driver/#Validator

For #7283 I need to call a different overload of DbConnection.Open in the SQL Server provider. I'm adding a template method to allow this, but similar template methods could be useful in other providers. Tentative list of relevant methods based on what RelationalCommand calls:

• BeginTransaction
• Close
• EnlistTransaction
• State
• Dispose

We could also consider doing this for other Db