Oracle 5.0 Reference Manual page 358

myisampack
46 479 1
47 480 1
48 481 79 no endspace, no empty
49 560 79 no empty
50 639 79 no empty
51 718 79 no endspace
52 797 8 no empty
53 805 1
54 806 1
55 807 20 no empty
56 827 4 no zeros, zerofill(2)
57 831 4 no zeros, zerofill(1)
displays the following kinds of information:
myisampack
•
normal
The number of columns for which no extra packing is used.
•
empty-space
The number of columns containing values that are only spaces. These occupy one bit.
•
empty-zero
The number of columns containing values that are only binary zeros. These occupy one bit.
•
empty-fill
The number of integer columns that do not occupy the full byte range of their type. These are
changed to a smaller type. For example, a
column (one byte) if all its values are in the range from
TINYINT
•
pre-space
The number of decimal columns that are stored with leading spaces. In this case, each value
contains a count for the number of leading spaces.
•
end-space
The number of columns that have a lot of trailing spaces. In this case, each value contains a count
for the number of trailing spaces.
•
table-lookup
The column had only a small number of different values, which were converted to an
Huffman compression.
•
zero
The number of columns for which all values are zero.
•
Original trees
The initial number of Huffman trees.
•
After join
The number of distinct Huffman trees left after joining trees to save some header space.
After a table has been compressed, the
information about each column:
•
Type
The data type. The value may contain any of the following descriptors:
— Generate Compressed, Read-Only MyISAM Tables
BIGINT
lines displayed by
Field
338
14 4
14 4
15 9
2 9
2 9
16 9
2 9
17 1
3 9
3 9
2 9
2 9
column (eight bytes) can be stored as a
to 127.
-128
myisamchk -dvv
before
ENUM
include additional