Question about Database: what is "information_schema" ?

[cnymike]

When I look at my database isomg phpMyAdmin, I see two of them listed, "information_schema (17)" and "mystore (97)"

I'm not sure what the "information_schema" is. I did have someone help me recover from a corrupted database six months ago or so... is this some sort of remnant from a database recovery operation or something?

[DrByte]

information_schema is a system database, created and managed by MySQL automatically.

Leave it alone. You don't need to be concerned about it.

[cnymike]

So it is created by Zen Cart during the installation?

If I ever had to restore my store database from a backup then I would actually need to restore both databases?

[cnymike]

I have found more information on the information_schema here...
http://dev.mysql.com/doc/refman/5.0/...on-schema.html

But what I'm still not clear about is when does this database get created and is it of critical importance when trying to restore the store database from a backup?

For several years I have been diligently backing up my store database (mystore) and didn't even realize that this information_schema was there.

In the event I have some sort of catastrophic loss of my entire database, am I able to restore only the mystore databaseand have a functioning store if I am lacking the information_schema? In other words, does the information_schema get created -from- the mystore database?

I find this all quite confusing.

[kiddo]

It's not installed by, or a part of Zen Cart.

[cnymike]

So I guess you are saying that it has nothing to do with restoring a cart database then? I need not worry about it al all since it has nothing to do with Zen-Cart, per se?

Michael

[Ajeh]

IF you need to know more about the information_schema, which has nothing to do with Zen Cart, you should contact your hosting site and they can explain it better for you ...

Again, as DrByte has suggested, it is not something you should have to ever touch ...

[cnymike]

Gosh, I've asked my question several different ways and I've gotten several responses but all of them dance around the topic instead of directly answering my question. Sorry for the inconvenience. I -will- ask my web host and then I will post the reply so that perhaps when someone else asks the same question... and someone surely will... there will be a better answer for them to read.

[Website Rob]

Not sure why you are still confused?

It was already mentioned that "It's not installed by, or a part of Zen Cart."

You, yourself, provided a link that explains it nicely.

INFORMATION_SCHEMA provides access to database metadata.

Metadata is data about the data, such as the name of a database or table, the data type of a column, or access privileges. Other terms that sometimes are used for this information are data dictionary and system catalog.

INFORMATION_SCHEMA is the information database, the place that stores information about all the other databases that the MySQL server maintains. Inside INFORMATION_SCHEMA there are several read-only tables. They are actually views, not base tables, so there are no files associated with them.

In effect, we have a database named INFORMATION_SCHEMA, although the server does not create a database directory with that name. It is possible to select INFORMATION_SCHEMA as the default database with a USE statement, but it is possible only to read the contents of tables. You cannot insert into them, update them, or delete from them.

Now we know that INFORMATION_SCHEMA is information about the various databases on the Server. It is not created by anyone through their Hosting account nor by any script used within a Hosting account.


In other words, don't worry about it. Worry instead about maintaining and backing up "your" databases, created by yourself or by a script you are using.

[cnymike]

Understanding technical writing is not my forté. Your explanation did clear it up though, so thank you.

We're not all braniacs here :-)