SaidbakR SaidbakR -4 years ago 248
MySQL Question

No partitioning defined in Many to Many conjugation table

I have

Many to Many
relation between
jobs
and
eqtypes
so I have made a third table named
eqtype_jobs
. However, in this relation conjugation, normalization, table I did not make an independent primary key
id
for example, I just set both
job_id
and
eqtype_id
as a primary key. The following is the table structure:

CREATE TABLE `eqtype_jobs` (
`job_id` int(10) UNSIGNED NOT NULL,
`eqtype_id` int(4) UNSIGNED NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

--
-- Indexes for dumped tables
--

--
-- Indexes for table `eqtype_jobs`
--
ALTER TABLE `eqtype_jobs`
ADD PRIMARY KEY (`eqtype_id`,`job_id`),
ADD KEY `job_id` (`job_id`);

--
-- Constraints for dumped tables
--

--
-- Constraints for table `eqtype_jobs`
--
ALTER TABLE `eqtype_jobs`
ADD CONSTRAINT `eqtype_jobs_ibfk_1` FOREIGN KEY (`job_id`) REFERENCES `jobs` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
ADD CONSTRAINT `eqtype_jobs_ibfk_2` FOREIGN KEY (`eqtype_id`) REFERENCES `eqtypes` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;


This is the first table that I omitted using independent primary key
id
. I have other Many to Many relations that I used and
id
in them before. However, phpMyAdmin shows the following notice when displaying
eqtype_jobs
table structure:


No partitioning defined!


Do the cause of this message about partitioning due to the absence of an independent primary key, i,e
id
? or the composite primary key of the table is not defined well?! Does this notice about portions will negatively affects the performance in the future?!

Answer Source

No, the message isn't saying anything bad about your table structure. From a grammar and UI aspect, it's a bit odd to have the exclamation point, but there's no problem here.

Partitioning is a way of dividing up the way your data is stored on disk. The area of the Structure page that you see deals with partitioning (see photo), and when no partition is configured you see the notification that alarmed you.

No partitions

If a partition is configured, you'll see the parameters:

Partition display

So you can safely ignore the Partitioning portion of that page.

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