diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
commit | 3f619478f796eddbba6e39502fe941b285dd97b1 (patch) | |
tree | e2c7b5777f728320e5b5542b6213fd3591ba51e2 /man/myisampack.1 | |
parent | Initial commit. (diff) | |
download | mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.tar.xz mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.zip |
Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | man/myisampack.1 | 837 |
1 files changed, 837 insertions, 0 deletions
diff --git a/man/myisampack.1 b/man/myisampack.1 new file mode 100644 index 00000000..89dab7d8 --- /dev/null +++ b/man/myisampack.1 @@ -0,0 +1,837 @@ +'\" t +.\" +.TH "\fBMYISAMPACK\fR" "1" "15 May 2020" "MariaDB 10.11" "MariaDB Database System" +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.\" myisampack +.\" compressed tables +.\" tables: compressed +.\" MyISAM: compressed tables +.SH "NAME" +myisampack \- generate compressed, read\-only MyISAM tables +.SH "SYNOPSIS" +.HP \w'\fBmyisampack\ [\fR\fB\fIoptions\fR\fR\fB]\ \fR\fB\fIfile_name\fR\fR\fB\ \&.\&.\&.\fR\ 'u +\fBmyisampack [\fR\fB\fIoptions\fR\fR\fB] \fR\fB\fIfile_name\fR\fR\fB \&.\&.\&.\fR +.SH "DESCRIPTION" +.PP +The +\fBmyisampack\fR +utility compresses +MyISAM +tables\&. +\fBmyisampack\fR +works by compressing each column in the table separately\&. Usually, +\fBmyisampack\fR +packs the data file 40%\(en70%\&. +.PP +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\&. +.PP +MySQL uses +mmap() +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 +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +After packing a table, it becomes read only\&. This is generally intended (such as when accessing packed tables on a CD)\&. +.RE +.PP +Invoke +\fBmyisampack\fR +like this: +.sp +.if n \{\ +.RS 4 +.\} +.nf +shell> \fBmyisampack [\fR\fB\fIoptions\fR\fR\fB] \fR\fB\fIfile_name\fR\fR\fB \&.\&.\&.\fR +.fi +.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 +\&.MYI +extension\&. +.PP +After you compress a table with +\fBmyisampack\fR, you should use +\fBmyisamchk \-rq\fR +to rebuild its indexes\&. +\fBmyisamchk\fR(1)\&. +.PP +\fBmyisampack\fR +supports the following options\&. It also reads option files and supports the options for processing them described at +Section\ \&4.2.3.3.1, \(lqCommand-Line Options that Affect Option-File Handling\(rq\&. +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +.\" myisampack: help option +.\" help option: myisampack +\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 +.\} +.\" myisampack: backup option +.\" backup option: myisampack +\fB\-\-backup\fR, +\fB\-b\fR +.sp +Make a backup of each table's data file using the name +\fItbl_name\fR\&.OLD\&. +.RE +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +.\" myisampack: character-sets-dir option +.\" character-sets-dir option: myisampack +\fB\-\-character\-sets\-dir=\fR\fB\fIpath\fR\fR +.sp +The directory where character sets are installed\&. See +Section\ \&9.5, \(lqCharacter Set Configuration\(rq\&. +.RE +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +.\" myisampack: debug option +.\" debug option: myisampack +\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 +.IP \(bu 2.3 +.\} +.\" myisampack: force option +.\" force option: myisampack +\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 +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 +.\} +.\" myisampack: join option +.\" join option: myisampack +\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\&. The join operation does not create a +\&.frm +file for +\fIbig_tbl_name\fR, so after the join operation finishes, copy the +\&.frm +file from one of the source tables and name it +\fIbig_tbl_name\fR\&.frm\&. +.RE +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +.\" myisampack: silent option +.\" silent option: myisampack +\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 +.\} +.\" myisampack: test option +.\" test option: myisampack +\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 +.\} +.\" myisampack: tmpdir option +.\" tmpdir option: myisampack +\fB\-\-tmpdir=\fR\fB\fIpath\fR\fR, +\fB\-T \fR\fB\fIpath\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 +.\} +.\" myisampack: verbose option +.\" verbose option: myisampack +\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 +.\} +.\" myisampack: version option +.\" version option: myisampack +\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 +.\} +.\" myisampack: wait option +.\" wait option: myisampack +\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 +.\" examples: compressed tables +.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 monty my 994128 Apr 17 19:00 station\&.MYD +\-rw\-rw\-r\-\- 1 monty my 53248 Apr 17 19:00 station\&.MYI +\-rw\-rw\-r\-\- 1 monty my 5767 Apr 17 19:00 station\&.frm +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> \fBls \-l station\&.*\fR +\-rw\-rw\-r\-\- 1 monty my 127874 Apr 17 19:00 station\&.MYD +\-rw\-rw\-r\-\- 1 monty my 55296 Apr 17 19:04 station\&.MYI +\-rw\-rw\-r\-\- 1 monty my 5767 Apr 17 19:00 station\&.frm +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, you must run +\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 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc., 2010-2020 MariaDB Foundation +.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 02110-1335 USA or see http://www.gnu.org/licenses/. +.sp +.SH "SEE ALSO" +For more information, please refer to the MariaDB Knowledge Base, available online at https://mariadb.com/kb/ +.SH AUTHOR +MariaDB Foundation (http://www.mariadb.org/). |