A database: the giant warehouse

A giant warehouse for information

If you jot notes just anywhere,
they are really hard to find later.
You cannot recall where you put them.
So a big shop keeps
a separate warehouse
that stacks goods in fixed spots.
A database is that kind of warehouse.
Instead of leaving information scattered,
it packs it away neatly and in order.

Tap the scattered notes and the orderly warehouse to compare. Which is easier to search?

In scattered notes,
finding even one takes a long fumble.
In an orderly warehouse,
if you know the spot you grab it at once.
For the very same information,
how you store it
changes the search speed a lot.
So then, in what shape
does a database hold information?

It is usually tidied into a table

A database usually tidies information
into the shape of a table.
One horizontal line is one record.
We call this a row.
For example, one person's information.
One vertical slot is a field.
We call this a column.
Names go with names, ages with ages,
lined up neatly in the same slot.

Tap a row and a column to explore. A horizontal line is one record, a vertical slot is one field.

Tidied into a table,
it takes in at a glance.
Follow a row and one person's information
runs along in a line,
follow a column and the same field
gathers side by side.
With everything lined up like this,
you can tell at once
what is where.
So how do we put in new information?

We pack it into the right spot

When new information comes in,
we do not toss it just anywhere.
First we decide which table it joins.
Person data goes to the person table.
Then each value
goes one by one into the right column.
The name into the name slot,
the age into the age slot.
Only by placing it in the right spot
can we find it later without a fumble.

Tap each new piece of data to file it into the right column. Fill them all to complete one row.

Putting each value in its right slot,
one record came together neatly.
Because the spots are set,
there is no confusion while filling.
As records pile up one by one,
the table grows longer
and the warehouse fills up.
But if it is like this,
could we not just write into a file?

How is it different from a file?

Information stays even in a file.
But two things are weak.
One, if many write at once,
it can get jumbled or go missing.
Two, when information grows huge,
finding the one you want takes ages.
A database does both of these well.
Even if many arrive at once it stores them safely,
and no matter how much, it finds fast.

Tap the file and the database panels to compare. See the difference: safe all at once, and fast search.

The difference shows.
A file struggles as it grows,
while a database handles it with ease.
So places with lots of information,
like shops or schools,
almost all use a database.
To store safely all at once,
and to find fast anytime.
That is the big strength of a database.

Let's wrap up

Gathered on one line, it is this.
A database is an orderly,
giant warehouse that holds information.
It usually tidies into a table,
where a row is one record, a column one field.
New information packs neatly into the right slot.
What sets it apart from a file
is storing safely all at once
and finding fast among a huge pile.

Tap the key points in order to review. (giant warehouse → tidy into a table → file into the right slot → safe and fast search)

Now you know what kind
of warehouse a database is.
We said it packs information
neatly into a table.
But when information reaches hundreds of millions,
how does it find the one row
you want, out of so many,
that fast?
Let's peek into that fast finding
together in the next lesson.