maria-developers team mailing list archive
-
maria-developers team
-
Mailing list archive
-
Message #12758
Re: Request for Discussion: Structure for JSON histogram objects
Hi, Sergey!
One point here, that we've learned the hard way on privilege tables,
store the current server version too. So that when (not if!) you'll
change the structure in the future, you won't need to resort to various
heuristics when interpreting a row.
On Jun 04, Sergey Petrunia wrote:
> Just to clarify: we are looking at two options currently.
> Please find their description below.
>
> == Current mysql.column_stats ==
>
> Currently, MariaDB defines mysql.column_stats as:
>
> CREATE TABLE column_stats (
> db_name varchar(64) COLLATE utf8mb3_bin NOT NULL,
> table_name varchar(64) COLLATE utf8mb3_bin NOT NULL,
> column_name varchar(64) COLLATE utf8mb3_bin NOT NULL,
> min_value varbinary(255) DEFAULT NULL,
> max_value varbinary(255) DEFAULT NULL,
> nulls_ratio decimal(12,4) DEFAULT NULL,
> avg_length decimal(12,4) DEFAULT NULL,
> avg_frequency decimal(12,4) DEFAULT NULL,
> hist_size tinyint(3) unsigned DEFAULT NULL,
> hist_type enum('SINGLE_PREC_HB','DOUBLE_PREC_HB')
> COLLATE utf8mb3_bin DEFAULT NULL,
> histogram varbinary(255) DEFAULT NULL,
> PRIMARY KEY (db_name,table_name,column_name)
> );
Regards,
Sergei
VP of MariaDB Server Engineering
and security@xxxxxxxxxxx
References