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839 lines
19 KiB
839 lines
19 KiB
'\" t
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.\" Title: \fBmyisampack\fR
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.\" Author: [FIXME: author] [see http://docbook.sf.net/el/author]
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.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
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.\" Date: 09/06/2019
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.\" Manual: MySQL Database System
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.\" Source: MySQL 8.0
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.\" Language: English
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.\"
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.TH "\FBMYISAMPACK\FR" "1" "09/06/2019" "MySQL 8\&.0" "MySQL Database System"
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.\" -----------------------------------------------------------------
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.\" * Define some portability stuff
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.\" -----------------------------------------------------------------
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.\" http://bugs.debian.org/507673
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.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.ie \n(.g .ds Aq \(aq
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.el .ds Aq '
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.\" -----------------------------------------------------------------
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.\" * set default formatting
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.\" -----------------------------------------------------------------
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.\" disable hyphenation
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.nh
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.\" disable justification (adjust text to left margin only)
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.ad l
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.\" -----------------------------------------------------------------
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.\" * MAIN CONTENT STARTS HERE *
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.\" -----------------------------------------------------------------
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.SH "NAME"
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myisampack \- generate compressed, read\-only MyISAM tables
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.SH "SYNOPSIS"
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.HP \w'\fBmyisampack\ [\fR\fB\fIoptions\fR\fR\fB]\ \fR\fB\fIfile_name\fR\fR\fB\ \&.\&.\&.\fR\ 'u
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\fBmyisampack [\fR\fB\fIoptions\fR\fR\fB] \fR\fB\fIfile_name\fR\fR\fB \&.\&.\&.\fR
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.SH "DESCRIPTION"
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.PP
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|
The
|
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\fBmyisampack\fR
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utility compresses
|
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MyISAM
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tables\&.
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\fBmyisampack\fR
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works by compressing each column in the table separately\&. Usually,
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\fBmyisampack\fR
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packs the data file 40% to 70%\&.
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.PP
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When the table is used later, the server reads into memory the information needed to decompress columns\&. This results in much better performance when accessing individual rows, because you only have to uncompress exactly one row\&.
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.PP
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|
MySQL uses
|
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mmap()
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|
when possible to perform memory mapping on compressed tables\&. If
|
|
mmap()
|
|
does not work, MySQL falls back to normal read/write file operations\&.
|
|
.PP
|
|
Please note the following:
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
If the
|
|
\fBmysqld\fR
|
|
server was invoked with external locking disabled, it is not a good idea to invoke
|
|
\fBmyisampack\fR
|
|
if the table might be updated by the server during the packing process\&. It is safest to compress tables with the server stopped\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
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|
.\}
|
|
.el \{\
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|
.sp -1
|
|
.IP \(bu 2.3
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|
.\}
|
|
After packing a table, it becomes read only\&. This is generally intended (such as when accessing packed tables on a CD)\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fBmyisampack\fR
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|
does not support partitioned tables\&.
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|
.RE
|
|
.PP
|
|
Invoke
|
|
\fBmyisampack\fR
|
|
like this:
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
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|
shell> \fBmyisampack [\fR\fB\fIoptions\fR\fR\fB] \fR\fB\fIfile_name\fR\fR\fB \&.\&.\&.\fR
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.fi
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|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.PP
|
|
Each file name argument should be the name of an index (\&.MYI) file\&. If you are not in the database directory, you should specify the path name to the file\&. It is permissible to omit the
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\&.MYI
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extension\&.
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|
.PP
|
|
After you compress a table with
|
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\fBmyisampack\fR, use
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|
\fBmyisamchk \-rq\fR
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|
to rebuild its indexes\&.
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|
\fBmyisamchk\fR(1)\&.
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|
.PP
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|
\fBmyisampack\fR
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|
supports the following options\&. It also reads option files and supports the options for processing them described at
|
|
Section\ \&4.2.2.3, \(lqCommand-Line Options that Affect Option-File Handling\(rq\&.
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|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-help\fR,
|
|
\fB\-?\fR
|
|
.sp
|
|
Display a help message and exit\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-backup\fR,
|
|
\fB\-b\fR
|
|
.sp
|
|
Make a backup of each table\*(Aqs data file using the name
|
|
\fItbl_name\fR\&.OLD\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
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|
.sp -1
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|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-character\-sets\-dir=\fR\fB\fIdir_name\fR\fR
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|
.sp
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|
The directory where character sets are installed\&. See
|
|
Section\ \&10.15, \(lqCharacter Set Configuration\(rq\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
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|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-debug[=\fR\fB\fIdebug_options\fR\fR\fB]\fR,
|
|
\fB\-# [\fR\fB\fIdebug_options\fR\fR\fB]\fR
|
|
.sp
|
|
Write a debugging log\&. A typical
|
|
\fIdebug_options\fR
|
|
string is
|
|
d:t:o,\fIfile_name\fR\&. The default is
|
|
d:t:o\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
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|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-force\fR,
|
|
\fB\-f\fR
|
|
.sp
|
|
Produce a packed table even if it becomes larger than the original or if the intermediate file from an earlier invocation of
|
|
\fBmyisampack\fR
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|
exists\&. (\fBmyisampack\fR
|
|
creates an intermediate file named
|
|
\fItbl_name\fR\&.TMD
|
|
in the database directory while it compresses the table\&. If you kill
|
|
\fBmyisampack\fR, the
|
|
\&.TMD
|
|
file might not be deleted\&.) Normally,
|
|
\fBmyisampack\fR
|
|
exits with an error if it finds that
|
|
\fItbl_name\fR\&.TMD
|
|
exists\&. With
|
|
\fB\-\-force\fR,
|
|
\fBmyisampack\fR
|
|
packs the table anyway\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-join=\fR\fB\fIbig_tbl_name\fR\fR,
|
|
\fB\-j \fR\fB\fIbig_tbl_name\fR\fR
|
|
.sp
|
|
Join all tables named on the command line into a single packed table
|
|
\fIbig_tbl_name\fR\&. All tables that are to be combined
|
|
\fImust\fR
|
|
have identical structure (same column names and types, same indexes, and so forth)\&.
|
|
.sp
|
|
\fIbig_tbl_name\fR
|
|
must not exist prior to the join operation\&. All source tables named on the command line to be merged into
|
|
\fIbig_tbl_name\fR
|
|
must exist\&. The source tables are read for the join operation but not modified\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-silent\fR,
|
|
\fB\-s\fR
|
|
.sp
|
|
Silent mode\&. Write output only when errors occur\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-test\fR,
|
|
\fB\-t\fR
|
|
.sp
|
|
Do not actually pack the table, just test packing it\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-tmpdir=\fR\fB\fIdir_name\fR\fR,
|
|
\fB\-T \fR\fB\fIdir_name\fR\fR
|
|
.sp
|
|
Use the named directory as the location where
|
|
\fBmyisampack\fR
|
|
creates temporary files\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-verbose\fR,
|
|
\fB\-v\fR
|
|
.sp
|
|
Verbose mode\&. Write information about the progress of the packing operation and its result\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-version\fR,
|
|
\fB\-V\fR
|
|
.sp
|
|
Display version information and exit\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
\fB\-\-wait\fR,
|
|
\fB\-w\fR
|
|
.sp
|
|
Wait and retry if the table is in use\&. If the
|
|
\fBmysqld\fR
|
|
server was invoked with external locking disabled, it is not a good idea to invoke
|
|
\fBmyisampack\fR
|
|
if the table might be updated by the server during the packing process\&.
|
|
.RE
|
|
.PP
|
|
The following sequence of commands illustrates a typical table compression session:
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
|
|
shell> \fBls \-l station\&.*\fR
|
|
\-rw\-rw\-r\-\- 1 jones my 994128 Apr 17 19:00 station\&.MYD
|
|
\-rw\-rw\-r\-\- 1 jones my 53248 Apr 17 19:00 station\&.MYI
|
|
shell> \fBmyisamchk \-dvv station\fR
|
|
MyISAM file: station
|
|
Isam\-version: 2
|
|
Creation time: 1996\-03\-13 10:08:58
|
|
Recover time: 1997\-02\-02 3:06:43
|
|
Data records: 1192 Deleted blocks: 0
|
|
Datafile parts: 1192 Deleted data: 0
|
|
Datafile pointer (bytes): 2 Keyfile pointer (bytes): 2
|
|
Max datafile length: 54657023 Max keyfile length: 33554431
|
|
Recordlength: 834
|
|
Record format: Fixed length
|
|
table description:
|
|
Key Start Len Index Type Root Blocksize Rec/key
|
|
1 2 4 unique unsigned long 1024 1024 1
|
|
2 32 30 multip\&. text 10240 1024 1
|
|
Field Start Length Type
|
|
1 1 1
|
|
2 2 4
|
|
3 6 4
|
|
4 10 1
|
|
5 11 20
|
|
6 31 1
|
|
7 32 30
|
|
8 62 35
|
|
9 97 35
|
|
10 132 35
|
|
11 167 4
|
|
12 171 16
|
|
13 187 35
|
|
14 222 4
|
|
15 226 16
|
|
16 242 20
|
|
17 262 20
|
|
18 282 20
|
|
19 302 30
|
|
20 332 4
|
|
21 336 4
|
|
22 340 1
|
|
23 341 8
|
|
24 349 8
|
|
25 357 8
|
|
26 365 2
|
|
27 367 2
|
|
28 369 4
|
|
29 373 4
|
|
30 377 1
|
|
31 378 2
|
|
32 380 8
|
|
33 388 4
|
|
34 392 4
|
|
35 396 4
|
|
36 400 4
|
|
37 404 1
|
|
38 405 4
|
|
39 409 4
|
|
40 413 4
|
|
41 417 4
|
|
42 421 4
|
|
43 425 4
|
|
44 429 20
|
|
45 449 30
|
|
46 479 1
|
|
47 480 1
|
|
48 481 79
|
|
49 560 79
|
|
50 639 79
|
|
51 718 79
|
|
52 797 8
|
|
53 805 1
|
|
54 806 1
|
|
55 807 20
|
|
56 827 4
|
|
57 831 4
|
|
shell> \fBmyisampack station\&.MYI\fR
|
|
Compressing station\&.MYI: (1192 records)
|
|
\- Calculating statistics
|
|
normal: 20 empty\-space: 16 empty\-zero: 12 empty\-fill: 11
|
|
pre\-space: 0 end\-space: 12 table\-lookups: 5 zero: 7
|
|
Original trees: 57 After join: 17
|
|
\- Compressing file
|
|
87\&.14%
|
|
Remember to run myisamchk \-rq on compressed tables
|
|
shell> \fBmyisamchk \-rq station\fR
|
|
\- check record delete\-chain
|
|
\- recovering (with sort) MyISAM\-table \*(Aqstation\*(Aq
|
|
Data records: 1192
|
|
\- Fixing index 1
|
|
\- Fixing index 2
|
|
shell> \fBmysqladmin \-uroot flush\-tables\fR
|
|
shell> \fBls \-l station\&.*\fR
|
|
\-rw\-rw\-r\-\- 1 jones my 127874 Apr 17 19:00 station\&.MYD
|
|
\-rw\-rw\-r\-\- 1 jones my 55296 Apr 17 19:04 station\&.MYI
|
|
shell> \fBmyisamchk \-dvv station\fR
|
|
MyISAM file: station
|
|
Isam\-version: 2
|
|
Creation time: 1996\-03\-13 10:08:58
|
|
Recover time: 1997\-04\-17 19:04:26
|
|
Data records: 1192 Deleted blocks: 0
|
|
Datafile parts: 1192 Deleted data: 0
|
|
Datafile pointer (bytes): 3 Keyfile pointer (bytes): 1
|
|
Max datafile length: 16777215 Max keyfile length: 131071
|
|
Recordlength: 834
|
|
Record format: Compressed
|
|
table description:
|
|
Key Start Len Index Type Root Blocksize Rec/key
|
|
1 2 4 unique unsigned long 10240 1024 1
|
|
2 32 30 multip\&. text 54272 1024 1
|
|
Field Start Length Type Huff tree Bits
|
|
1 1 1 constant 1 0
|
|
2 2 4 zerofill(1) 2 9
|
|
3 6 4 no zeros, zerofill(1) 2 9
|
|
4 10 1 3 9
|
|
5 11 20 table\-lookup 4 0
|
|
6 31 1 3 9
|
|
7 32 30 no endspace, not_always 5 9
|
|
8 62 35 no endspace, not_always, no empty 6 9
|
|
9 97 35 no empty 7 9
|
|
10 132 35 no endspace, not_always, no empty 6 9
|
|
11 167 4 zerofill(1) 2 9
|
|
12 171 16 no endspace, not_always, no empty 5 9
|
|
13 187 35 no endspace, not_always, no empty 6 9
|
|
14 222 4 zerofill(1) 2 9
|
|
15 226 16 no endspace, not_always, no empty 5 9
|
|
16 242 20 no endspace, not_always 8 9
|
|
17 262 20 no endspace, no empty 8 9
|
|
18 282 20 no endspace, no empty 5 9
|
|
19 302 30 no endspace, no empty 6 9
|
|
20 332 4 always zero 2 9
|
|
21 336 4 always zero 2 9
|
|
22 340 1 3 9
|
|
23 341 8 table\-lookup 9 0
|
|
24 349 8 table\-lookup 10 0
|
|
25 357 8 always zero 2 9
|
|
26 365 2 2 9
|
|
27 367 2 no zeros, zerofill(1) 2 9
|
|
28 369 4 no zeros, zerofill(1) 2 9
|
|
29 373 4 table\-lookup 11 0
|
|
30 377 1 3 9
|
|
31 378 2 no zeros, zerofill(1) 2 9
|
|
32 380 8 no zeros 2 9
|
|
33 388 4 always zero 2 9
|
|
34 392 4 table\-lookup 12 0
|
|
35 396 4 no zeros, zerofill(1) 13 9
|
|
36 400 4 no zeros, zerofill(1) 2 9
|
|
37 404 1 2 9
|
|
38 405 4 no zeros 2 9
|
|
39 409 4 always zero 2 9
|
|
40 413 4 no zeros 2 9
|
|
41 417 4 always zero 2 9
|
|
42 421 4 no zeros 2 9
|
|
43 425 4 always zero 2 9
|
|
44 429 20 no empty 3 9
|
|
45 449 30 no empty 3 9
|
|
46 479 1 14 4
|
|
47 480 1 14 4
|
|
48 481 79 no endspace, no empty 15 9
|
|
49 560 79 no empty 2 9
|
|
50 639 79 no empty 2 9
|
|
51 718 79 no endspace 16 9
|
|
52 797 8 no empty 2 9
|
|
53 805 1 17 1
|
|
54 806 1 3 9
|
|
55 807 20 no empty 3 9
|
|
56 827 4 no zeros, zerofill(2) 2 9
|
|
57 831 4 no zeros, zerofill(1) 2 9
|
|
.fi
|
|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.PP
|
|
\fBmyisampack\fR
|
|
displays the following kinds of information:
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
normal
|
|
.sp
|
|
The number of columns for which no extra packing is used\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
empty\-space
|
|
.sp
|
|
The number of columns containing values that are only spaces\&. These occupy one bit\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
empty\-zero
|
|
.sp
|
|
The number of columns containing values that are only binary zeros\&. These occupy one bit\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
empty\-fill
|
|
.sp
|
|
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
|
|
BIGINT
|
|
column (eight bytes) can be stored as a
|
|
TINYINT
|
|
column (one byte) if all its values are in the range from
|
|
\-128
|
|
to
|
|
127\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
pre\-space
|
|
.sp
|
|
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\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
end\-space
|
|
.sp
|
|
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\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
table\-lookup
|
|
.sp
|
|
The column had only a small number of different values, which were converted to an
|
|
ENUM
|
|
before Huffman compression\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
zero
|
|
.sp
|
|
The number of columns for which all values are zero\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
Original trees
|
|
.sp
|
|
The initial number of Huffman trees\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
After join
|
|
.sp
|
|
The number of distinct Huffman trees left after joining trees to save some header space\&.
|
|
.RE
|
|
.PP
|
|
After a table has been compressed, the
|
|
Field
|
|
lines displayed by
|
|
\fBmyisamchk \-dvv\fR
|
|
include additional information about each column:
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
Type
|
|
.sp
|
|
The data type\&. The value may contain any of the following descriptors:
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
constant
|
|
.sp
|
|
All rows have the same value\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
no endspace
|
|
.sp
|
|
Do not store endspace\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
no endspace, not_always
|
|
.sp
|
|
Do not store endspace and do not do endspace compression for all values\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
no endspace, no empty
|
|
.sp
|
|
Do not store endspace\&. Do not store empty values\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
table\-lookup
|
|
.sp
|
|
The column was converted to an
|
|
ENUM\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
zerofill(\fIN\fR)
|
|
.sp
|
|
The most significant
|
|
\fIN\fR
|
|
bytes in the value are always 0 and are not stored\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
no zeros
|
|
.sp
|
|
Do not store zeros\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
always zero
|
|
.sp
|
|
Zero values are stored using one bit\&.
|
|
.RE
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
Huff tree
|
|
.sp
|
|
The number of the Huffman tree associated with the column\&.
|
|
.RE
|
|
.sp
|
|
.RS 4
|
|
.ie n \{\
|
|
\h'-04'\(bu\h'+03'\c
|
|
.\}
|
|
.el \{\
|
|
.sp -1
|
|
.IP \(bu 2.3
|
|
.\}
|
|
Bits
|
|
.sp
|
|
The number of bits used in the Huffman tree\&.
|
|
.RE
|
|
.PP
|
|
After you run
|
|
\fBmyisampack\fR, use
|
|
\fBmyisamchk\fR
|
|
to re\-create any indexes\&. At this time, you can also sort the index blocks and create statistics needed for the MySQL optimizer to work more efficiently:
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
|
|
shell> \fBmyisamchk \-rq \-\-sort\-index \-\-analyze \fR\fB\fItbl_name\fR\fR\fB\&.MYI\fR
|
|
.fi
|
|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.PP
|
|
After you have installed the packed table into the MySQL database directory, you should execute
|
|
\fBmysqladmin flush\-tables\fR
|
|
to force
|
|
\fBmysqld\fR
|
|
to start using the new table\&.
|
|
.PP
|
|
To unpack a packed table, use the
|
|
\fB\-\-unpack\fR
|
|
option to
|
|
\fBmyisamchk\fR\&.
|
|
.SH "COPYRIGHT"
|
|
.br
|
|
.PP
|
|
Copyright \(co 1997, 2019, Oracle and/or its affiliates. All rights reserved.
|
|
.PP
|
|
This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.
|
|
.PP
|
|
This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
|
|
.PP
|
|
You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/.
|
|
.sp
|
|
.SH "SEE ALSO"
|
|
For more information, please refer to the MySQL Reference Manual,
|
|
which may already be installed locally and which is also available
|
|
online at http://dev.mysql.com/doc/.
|
|
.SH AUTHOR
|
|
Oracle Corporation (http://dev.mysql.com/).
|
|
|