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Commands in 'discovery' order...

mysql  --user {username}  --host {network_name}  --password
Password: *****

  show databases;            What database (table sets) you have access to.
  use {database}             Work in this database set
  show tables;               What tables are in this database
  describe {table};          What columns and types are in this table
  show create table {table}  The command to use to re-recreate the table
                              (does not show REFERENCES comments)

--------
Create Table

   create table {table} ({name} {type},... );

to modify you need to use    alter table ....

Add data to tables....

   load data
   insert

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Administer

Creating a Database (administrator)

Adding users

Granting Access

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Safe snapshots of MySQL tables (for backups) on LVM systems


#!/usr/bin/perl
#
# On a LINUX LVM system, get mysql to flush and do a LVM snapshot
# before making a backup of the mysql snapshot
#
#

$SnapDir="/snapshots/mysql";
$SnapDev="/dev/asylum/mysql_snapshot";
$SnapSize="128M";
$MySQLDev="/dev/asylum/mysql";

$OnOff=$ARGV[0];    # Are we creating or removing a mysql table snapshot
chomp $OnOff;

if ($ARGV[1] eq "-v" || $ARGV[1] eq "-v\n") {
  $Verbose="y";
  $MountParams="-v -t ext4 -o ro,noatime,nodiratime,noexec,nosuid,nodev,barrier=0";
  $UMountParams="-v";
} else {
  $Verbose="n";
  $MountParams="-t ext4 -o ro,noatime,nodiratime,noexec,nosuid,nodev,barrier=0";
  $UMountParams="";
}

if ($OnOff eq "on") {

  # connect mysql ROOT
  use DBI;
  $DB=DBI->connect("DBI:mysql:mysql" . ";mysql_read_default_file=/root/.my.cnf", root, $password)
    or die "Could not connect to MySQL\n";

  # flush and lock all tables
  $DB->do("flush tables with read lock;")
    or die "Can't flush and lock tables: ",$DB->errstr,"\n";

  # create the LVM snapshot device
    system ("lvcreate --size $SnapSize --snapshot --name mysql_snapshot $MySQLDev > /dev/null 2>&1") == 0
      or die "Can't create snapshot: $?\n";

  # unlock the tables so MySQL can continue serving clients
  # After this we don't have to talk to MySQL at all anymore.
  $DB->do("unlock tables");
  $DB->disconnect;


  # mount up the snapshot volume
  system ("mount $MountParams $SnapDev $SnapDir") == 0
    or die "Unable to mount snapshot: $?\n";


} elsif ($OnOff eq "off") {

  # Unmount the snapshot
  system ("umount $UMountParams $SnapDir") == 0
    or die "Can't unmount snapshot: $?\n";

  # Delete the snapshot volume
  system ("lvremove --force $SnapDev > /dev/null 2>&1") == 0
    or system ("lvremove --force $SnapDev > /dev/null") == 0
      or die "Can't remove the snapshot volume: $?\n";

} else {
  die "Invalid parameter used on command line.\n";
}

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