MySQL 5.7.13 Hidden Gems


The Release Notes for MySQL 5.7.13 has some interesting notices about account length, JSON short cuts, and more.

A Rose By Any Other Name

Way back in 5.7.8 the account username was increased from sixteen to thirty two characters. Yeah! For many years this has been heavily requested. Now this has been incorporated in the definer fields of event and proc tables plus the grantor field of procs_priv and tables_priv tables. To do this these columns where bumped up from CHAR(77)) to CHAR(93) to hold the longer username@hostname data.

JSON Inline Path

An unquoting extraction operator ->>, called an inline path operator, is for use with JSON documents stored in MySQL. The new operator is similar to the -> operator which is a shotcut for JSON_EXTRACT. But it goes a step further in that it performs JSON unquoting of the value as well. For a JSON column mycol and JSON path expression mypath, the following three expressions are equivalent:


JSON_UNQUOTE( JSON_EXTRACT(jsoncolumn, "$.jsondata") )
JSON_UNQUOTE(jsoncol->"$.jsondata")
mycol->>"$.jsondata"

This new ->> operator can be used in SQL statements where JSON_UNQUOTE(JSON_EXTRACT()) would be allowed. This includes SELECT lists, WHERE and HAVING clauses, and ORDER BY and GROUP BY clauses.

Systemd and Multiple Severs

Those of you running Systemd equipped distros need to read Configuring Multiple MySQL Instances Using systemd if you desire to run multiple servers on a single host.

And there is more

The release notes for ’13 cover bugs fixed, audit log granularity, and more. Please take a few minutes to read this.

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