Databases Reference
In-Depth Information
Next, type the column's header, which will appear at the top of the column (
Fig-
ure 16-7
). Finally, choose the column's source. This is an expression that
innotop
compiles into a function internally. You can use names from
SHOW VARIABLES
and
SHOW
STATUS
as though they're variables in an equation. We use some parentheses and Perl-
ish “or” defaults to prevent division by zero, but otherwise this equation is pretty
straightforward. We also use an
innotop
transformation called
percent()
to format the
resulting column as a percentage; check the
innotop
documentation for more on that.
Figure 16-8
shows the expression.
Figure 16-7. Adding a header (text for column)
Figure 16-8. Adding a header (expression to calculate)
Press Enter, and you'll see the table definition just as before, but with the new column
added at the bottom. Press the + key a few times to move it up the list, next to the
key_buffer_hit
column, and then press
q
to exit the table editor.
Voilà
: your new col-
umn, nestled between
KCacheHit
and
BpsIn
(
Figure 16-9
). It's easy to customize
innotop
to monitor what you want. You can even write plugins if it really can't do what
you need. There's more documentation at
http://code.google.com/p/innotop/
.
Figure 16-9. Adding a header (result)
