- heavily reworked the comments and layout of the new sample my.cnf file

   as requested by PeterZ

support-files/my-innodb-heavy-4G.cnf.sh

 #BEGIN CONFIG INFO
-#DESCR:  4G,Innodb only,ACID, Few Connections heavy queries
+#DESCR: 4GB RAM, InnoDB only, ACID, few connections, heavy queries
 #TYPE: SYSTEM
 #END CONFIG INFO
 
-# This is example config file for systems with 4G of memory running mostly MySQL
-# using MyISAM only tables and running complex queries with few connections
-# 
-
-
-
-
 #
-# You can copy this file to
-# /etc/my.cnf to set global options,
-# mysql-data-dir/my.cnf to set server-specific options (in this
-# installation this directory is @localstatedir@) or
+# This is a MySQL example config file for systems with 4GB of memory
+# running mostly MySQL using InnoDB only tables and performing complex
+# queries with few connections.
+# 
+# You can copy this file to /etc/my.cnf to set global options,
+# mysql-data-dir/my.cnf to set server-specific options 
+# (@localstatedir@ for this installation) or to
 # ~/.my.cnf to set user-specific options.
 #
-# One can in this file use all long options that the program supports.
-# If you want to know which options a program support, run the program
-# with --help option.
-
-
+# In this file, you can use all long options that the program supports.
+# If you want to know the options a program supports, run the program
+# with the "--help" option.
+#
+# More detailed information about the individual options can also be
+# found in the manual.
+#
 
-# The following options will be passed to all MySQL clients
-# But note, only client programs shipped by MySQL are guarantied to read it
-# If you wish your software to read this section you would need to specify
-# it as an option during MySQL client library initialization
+#
+# The following options will be read by MySQL client applications.
+# Note that only client applications shipped by MySQL are guaranteed
+# to read this section. If you want your own MySQL client program to
+# honor these values, you need to specify it as an option during the
+# MySQL client library initialization.
+#
 [client]
-#password	= your_password
+#password	= [your_password]
 port		= @MYSQL_TCP_PORT@
 socket		= @MYSQL_UNIX_ADDR@
 
-# ********** Here follows entries for some specific programs
+# *** Application-specific options follow here ***
 
+#
 # The MySQL server
+#
 [mysqld]
-# generic configuration options
 
+# generic configuration options
 port		= @MYSQL_TCP_PORT@
 socket		= @MYSQL_UNIX_ADDR@
 
-
-# Back Log is a number of connection OS can keep in queue, before MySQL
-# connection manager thread has processed them. If you have very intensive
-# connection rate and experience "connection refused" errors you might need
-# to increase this value
+# back_log is the number of connections the operating system can keep in
+# the listen queue, before the MySQL connection manager thread has
+# processed them. If you have a very high connection rate and experience
+# "connection refused" errors, you might need to increase this value.
+# Check your OS documentation for the maximum value of this parameter.
+# Attempting to set back_log higher than your operating system limit
+# will have no effect.
 back_log = 50
 
-
-# Don't listen on a TCP/IP port at all. This can be a security enhancement,
-# if all processes that need to connect to mysqld run on the same host.
-# All interaction with mysqld must be made via Unix sockets or named pipes.
+# Don't listen on a TCP/IP port at all. This can be a security
+# enhancement, if all processes that need to connect to mysqld run
+# on the same host.  All interaction with mysqld must be made via Unix
+# sockets or named pipes.
 # Note that using this option without enabling named pipes on Windows
 # (via the "enable-named-pipe" option) will render mysqld useless!
 #skip-networking
 
-# Maximum amount of concurrent sessions MySQL server will allow
-# One of these connections will be reserved for user with SUPER privelege
-# to allow administrator to login even if server is overloaded.
+# The maximum amount of concurrent sessions the MySQL server will
+# allow. One of these connections will be reserved for a user with
+# SUPER privileges to allow the administrator to login even if the
+# connection limit has been reached.
 max_connections = 100
 
-
-# Maximum amount of errors allowed per host. If this limit is reached
-# host will be blocked from connection MySQL server until "flush hosts"
-# is run or server restart. Invalid passwords as any other errors at 
-# connect phase results in increasing this value. See 
-# Aborted_Connects status variable for global counter.
+# Maximum amount of errors allowed per host. If this limit is reached,
+# the host will be blocked from connecting to the MySQL server until
+# "FLUSH HOSTS" has been run or the server was restarted. Invalid
+# passwords and other errors during the connect phase result in
+# increasing this value. See the "Aborted_Connects" status variable for
+# global counter.
 max_connect_errors = 10
 
-
-# Amount of tables server can keep open at the time. Each table 
-# may require up to 2 file handlers (for MERGE tables even more)
-# so make sure to have amount of open files allowed at least 4096
-# see open-files-limit in [mysqld_safe]
+# The number of open tables for all threads. Increasing this value
+# increases the number of file descriptors that mysqld requires.
+# Therefore you have to make sure to set the amount of open files
+# allowed to at least 4096 in the variable "open-files-limit" in
+# section [mysqld_safe]
 table_cache = 2048
 
-# Do not use file level locking. Enabled file locking give performance
-# hit, so use it only in case you have serveral database instances
-# running on the same files (note some restrictions still apply!) 
-# or if you use other software relaying on locking MyISAM tables 
-# on file level
-#enable-locking
+# Enable external file level locking. Enabled file locking will have a
+# negative impact on performance, so only use it in case you have
+# multiple database instances running on the same files (note some
+# restrictions still apply!) or if you use other software relying on
+# locking MyISAM tables on file level.
+#external-locking
 
-# This packets limits maximum size of BLOB server can handle 
-# as well as maximum query size server can process
-# enlarged dynamically, for each connection
+# The maximum size of a query packet the server can handle as well as
+# maximum query size server can process (Important when working with
+# large BLOBs).  enlarged dynamically, for each connection.
 max_allowed_packet = 16M
 
-# Binary log cache is used for logging transactions to binary log
-# all statements from transactions are buffered in binary log cache
-# and wrote to the binary log at once on commit
-# if transaction is large than this value disk temporary file is used.
-# This buffer is allocated per connection on first update statement 
-# in transaction
+# The size of the cache to hold the SQL statements for the binary log
+# during a transaction. If you often use big, multi-statement
+# transactions you can increase this value to get more performance. All
+# statements from transactions are buffered in the binary log cache and
+# are being written to the binary log at once after the COMMIT.  If the
+# transaction is larger than this value, temporary file on disk is used
+# instead.  This buffer is allocated per connection on first update
+# statement in transaction
 binlog_cache_size = 1M
 
+# Maximum allowed size for a single HEAP (in memory) table. This option
+# is a protection against the accidential creation of a very large HEAP
+# table which could otherwise use up all memory resources.
+max_heap_table_size = 64M
 
-# Maximum allowed size for single HEAP (in memory) table
-# This option is protection from accidential creation of the HEAP
-# table which would take all the memory resources
-max_heap_table_size=64M
-
-
-# Sort buffer used to perform sorts for some of ORDER BY and 
-# GROUP BY queries. If sorted data does not fit into sort buffer
-# Disk based merge sort is used - See sort_merge_passes.
-# Allocated per thread if sort is needed
+# Sort buffer is used to perform sorts for some ORDER BY and GROUP BY
+# queries. If sorted data does not fit into the sort buffer, a disk
+# based merge sort is used instead - See "sort_merge_passes". Allocated
+# per thread if sort is needed.
 sort_buffer_size = 8M
 
-# This buffer is used for optimization of full joins (joins without indexes)
-# Such joins are very bad for performance in most cases anyway, but having
-# this variable large reduces performance impact.
-# see select_full_join status variable for full joins count
-# Allocated per thread if full join is found
-join_buffer_size=8M
-
-
-# Cache threads on disconnect instead of destroying them
-# thread cache allows to greatly reduce amount of thread
-# creations needed if you have a lot of connections
+# This buffer is used for the optimization of full JOINs (JOINs without
+# indexes). Such JOINs are very bad for performance in most cases
+# anyway, but setting this variable to a large value reduces the
+# performance impact. See the "select_full_join" status variable for a
+# count of full JOINs. Allocated per thread if full join is found
+join_buffer_size = 8M
+
+# How many threads we should keep in a cache for reuse. When a client
+# disconnects, the client's threads are put in the cache if there aren't
+# more than thread_cache_size threads from before.  This greatly reduces
+# the amount of thread creations needed if you have a lot of new
+# connections. (Normally this doesn't give a notable performance
+# improvement if you have a good thread implementation.)
 thread_cache = 8
 
-
-# Try number of CPU's*(2..4) for thread_concurrency
-# This value makes sense only on few systems (as Solaris)
-# which support thread_concurrency() setting
+# This permits the application to give the threads system a hint for the
+# desired number of threads that should be run at the same time.  This
+# value only makes sense on systems that support the thread_concurrency()
+# function call (Sun Solaris, for example).
+# You should try [number of CPUs]*(2..4) for thread_concurrency
 thread_concurrency = 8
 
-
-# Query cache is used to cache SELECT results and later return
-# them without actual query execution for exactly the same query
-# Having query cache enabled may give great benefit if your have
-# typical queries and rarely changed tabled
-# see Qcache_lowmem_prunes status variable to check if current 
-# value is enough for your load
-# Note: In case your table change all the time or you never have
-# textually same queries query cache maay bring slowdown
-# instead of performance improvement
+# Query cache is used to cache SELECT results and later return them
+# without actual executing the same query once again. Having the query
+# cache enabled may result in significant speed improvements, if your
+# have a lot of identical queries and rarely changing tables. See the
+# "Qcache_lowmem_prunes" status variable to check if the current value
+# is high enough for your load.
+# Note: In case your tables change very often or if your queries are
+# textually different every time, the query cache may result in a
+# slowdown instead of a performance improvement.
 query_cache_size = 64M
 
-# Cache only result sets which are smaller than this limit
-# This setting is protection of very large result set overwriting
-# all queries in query cache
+# Only cache result sets that are smaller than this limit. This is to
+# protect the query cache of a very large result set overwriting all
+# other query results.
 query_cache_limit = 2M
 
-# Minimum word length to be indexed by full text search index
-# you might wish to decrease it if you need to search on shorter words
+# Minimum word length to be indexed by the full text search index.
+# You might wish to decrease it if you need to search for shorter words.
+# Note that you need to rebuild your FULLTEXT index, after you have
+# modified this value.
 ft_min_word_len = 4
 
-# If your system supports memlock() function you might use this option
-# while running MySQL to keep it locking in memory, avoid potential
-# swapping out in case of high memory pressure. Good for performance.
+# If your system supports the memlock() function call, you might want to
+# enable this option while running MySQL to keep it locked in memory and
+# to avoid potential swapping out in case of high memory pressure. Good
+# for performance.
 #memlock
 
-# Table type which is used by default, if not specified by CREATE TABLE
-# it affects only tables explicitly created by user.
+# Table type which is used by default when creating new tables, if not
+# specified differently during the CREATE TABLE statement.
 default_table_type = MYISAM
 
-# Thread stack size to use. This amount of memory is always reserved at 
-# connection time. MySQL itself usually needs no more than 64K of memory,
-# while if you use your own stack hungry UDF functions or OS requires more 
-# stack for some operations, you might need to set it higher
+# Thread stack size to use. This amount of memory is always reserved at
+# connection time. MySQL itself usually needs no more than 64K of
+# memory, while if you use your own stack hungry UDF functions or your
+# OS requires more stack for some operations, you might need to set this
+# to a higher value.
 thread_stack = 192K
 
-# Set default transaction isolation level. Levels available are:
+# Set the default transaction isolation level. Levels available are:
 # READ-UNCOMMITED, READ-COMMITED, REPEATABLE-READ, SERIALIZABLE
 transaction_isolation = REPEATABLE-READ
 
-# Maximum size for internal in memory temporary table. If table 
-# grows larger it is automatically converted to disk based table
-# This limitaion is for single table. There can be many of them.
+# Maximum size for internal (in-memory) temporary tables. If a table
+# grows larger than this value, it is automatically converted to disk
+# based table This limitation is for a single table. There can be many
+# of them.
 tmp_table_size = 64M
 
-# binary logging is required for acting MASTER in replication
-# You also need binary log if you need ability to do point
-# in time recovery from your latest backup
+# Enable binary logging. This is required for acting as a MASTER in a
+# replication configuration. You also need the binary log if you need
+# the ability to do point in time recovery from your latest backup.
 log_bin
 
-# If you're using chaining replication A->B->C you might wish to
-# turn on this option on server B. It makes updates done by
-# slave thread also logged in binary log. Normally they are not
+# If you're using replication with chained slaves (A->B->C), you need to
+# enable this option on server B. It enables logging of updates done by
+# the slave thread into the slave's binary log.
 #log_slave_updates
 
-
-# Full query log. Every query (even with incorrect syntax) server gets goes here.
-# Useful for debugging. Normally is disabled in production
+# Enable the full query log. Every query (even ones with incorrect
+# syntax) that the server receives will be logged. This is useful for
+# debugging, it is usually disabled in production use.
 #log
 
-# If you have  any problems with MySQL server you might enable Warnings logging and 
-# examine error log for possible explanations. 
+# Print warnings to the error log file.  If you have any problem with
+# MySQL you should enable logging of warnings and examine the error log
+# for possible explanations. 
 #log_warnings
 
-# Log slow queries. Slow queries are queries which take more than defined amount of time
-# or which do not use indexes well, if log_long_format is enabled
-# It is notmally good idea to have this on if you frequently add new queries to the system
+# Log slow queries. Slow queries are queries which take more than the
+# amount of time defined in "long_query_time" or which do not use
+# indexes well, if log_long_format is enabled. It is normally good idea
+# to have this turned on if you frequently add new queries to the
+# system.
 log_slow_queries
 
-
-# All queries taking more than this amount of time will be trated as slow. Do not use value 1
-# here as this will result even in very fast queries logged sometimes, as MySQL measures time with
-# second accuracy only.
+# All queries taking more than this amount of time (in seconds) will be
+# trated as slow. Do not use "1" as a value here, as this will result in
+# even very fast queries being logged from time to time (as MySQL
+# currently measures time with second accuracy only).
 long_query_time = 2
 
-# Log more information in slow query log. Normally it is good to have this on.
-# It results in logging of queries not using indexes additionally to long running queries.
+# Log more information in the slow query log. Normally it is good to
+# have this turned on. This will enable logging of queries that are not
+# using indexes in addition to long running queries.
 log_long_format
 
+# The directory used by MySQL for storing temporary files. For example,
+# it is used to perform disk based large sorts, as well as for internal
+# and explicit temporary tables. It might be good to put it on a
+# swapfs/tmpfs filesystem, if you do not create very large temporary
+# files. Alternatively you can put it on dedicated disk. You can
+# specify multiple paths here by separating them by ";" - they will then
+# be used in a round-robin fashion.
+#tmpdir = /tmp
 
 
-# Temporary directory is used by MySQL for storing temporary files, for example
-# used to do disk based large sorts, as well as for internal and explicit 
-# temporary tables.
-# It might be good to set it to swapfs/tmpfs filesystem if you do not have very
-# large temporary files created or set it to dedicated disk
-# You can specify several paths here spliting them by ";" they will be used in
-# round-robin fashion
-#tmpdir		= /tmp
+# ***  Replication related settings 
 
 
-#***  Replication related settings 
-
-
-# This value is required both for master ans slave
-# If you have single master it is typical to use value 1 for it
-# required unique id between 1 and 2^32 - 1
-# defaults to 1 if master-host is not set
-# but will not function as a master if omitted
+# Unique server identification number between 1 and 2^32-1. This value
+# is required for both master and slave hosts. It defaults to 1 if
+# "master-host" is not set, but will MySQL will not function as a master
+# if it is omitted.
 server-id = 1
 
-
-# To configure this server as Replication Slave you will need
-# to set its server_id to some unique value, different from Master 
-# and all slaves in the group.
-# You also can disable log-bin as logs are not required (while recomended)
-# for slaves
-# 
+# Replication Slave (comment out master section to use this)
+#
+# To configure this host as a replication slave, you can choose between
+# two methods :
 #
-# The recomended way to set MASTER settings for the slave are:
-# Use the CHANGE MASTER TO command (fully described in our manual) -
+# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
 #    the syntax is:
 #
 #    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
@@ -252,191 +262,221 @@ server-id = 1
 #    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
 #    MASTER_USER='joe', MASTER_PASSWORD='secret';
 #
-# However if you need to replicate slave configuration over several boxes
-# you can use old approach:
+# OR
 #
-#    Set the variables below. However, in case you choose this method, then
+# 2) Set the variables below. However, in case you choose this method, then
 #    start replication for the first time (even unsuccessfully, for example
 #    if you mistyped the password in master-password and the slave fails to
 #    connect), the slave will create a master.info file, and any later
-#    change in this file to the variables' values below will be ignored and
+#    changes in this file to the variable values below will be ignored and
 #    overridden by the content of the master.info file, unless you shutdown
 #    the slave server, delete master.info and restart the slaver server.
 #    For that reason, you may want to leave the lines below untouched
 #    (commented) and instead use CHANGE MASTER TO (see above)
 #
+# required unique id between 2 and 2^32 - 1
+# (and different from the master)
+# defaults to 2 if master-host is set
+# but will not function as a slave if omitted
+#server-id = 2
 #
 # The replication master for this slave - required
-#master-host     =   <hostname>
+#master-host = <hostname>
 #
 # The username the slave will use for authentication when connecting
 # to the master - required
-#master-user     =   <username>
+#master-user = <username>
 #
 # The password the slave will authenticate with when connecting to
 # the master - required
-#master-password =   <password>
+#master-password = <password>
 #
 # The port the master is listening on.
 # optional - defaults to 3306
-#master-port     =  <port>
+#master-port = <port>
 
-# Make Slave ReadOnly.  Only user with SUPER privelege and slave 
-# thread will be able to modify it. You might use it to ensure 
-# no applications will accidently modify slave instead of master
+# Make the slave read-only. Only users with the SUPER privilege and the
+# replication slave thread will be able to modify data on it. You can
+# use this to ensure that no applications will accidently modify data on
+# the slave instead of the master
 #read_only
 
 
-
 #*** MyISAM Specific options
 
 
-# Size of Key Buffer, used to cache index blocks for MyISAM tables
-# Do not set it larger than 30% of available memory, as some memory
-# is required by OS to cache rows.
-# Even if you're not using MyISAM tables still set it to 8-64M
-# as it will be used for internal temporary disk tables.
+# Size of the Key Buffer, used to cache index blocks for MyISAM tables.
+# Do not set it larger than 30% of your available memory, as some memory
+# is also required by the OS to cache rows. Even if you're not using
+# MyISAM tables, you should still set it to 8-64M as it will also be
+# used for internal temporary disk tables.
 key_buffer_size = 32M
 
-# Size of buffer used for doing full table scans for MyISAM tables
-# allocated per thread, as full scan is needed
+# Size of the buffer used for doing full table scans of MyISAM tables.
+# Allocated per thread, if a full scan is needed.
 read_buffer_size = 2M
 
-# Buffer is used for caching the rows while doing Sorts 
-# Allocated per thread, then needed
+# When reading rows in sorted order after a sort, the rows are read
+# through this buffer to avoid a disk seeks. You can improve ORDER BY
+# performance a lot, if set this to a high value.
+# Allocated per thread, when needed.
 read_rnd_buffer_size = 16M
 
-# The bulk insert tree is used for optimization of index modification
-# for bulk inserts (hundreds+ values) and LOAD DATA INFILE
-# Do not set larger than key_buffer_size  for optimal performance
-# This buffer is allocated than bulk insert is detected
+# MyISAM uses special tree-like cache to make bulk inserts (that is,
+# INSERT ... SELECT, INSERT ... VALUES (...), (...), ..., and LOAD DATA
+# INFILE) faster. This variable limits the size of the cache tree in
+# bytes per thread. Setting it to 0 will disable this optimisation.  Do
+# not set it larger than "key_buffer_size" for optimal performance.
+# This buffer is allocated when a bulk insert is detected.
 bulk_insert_buffer_size = 64M
 
-
-# This buffer is allocated than MySQL needs to rebuild the Index,
-# in REPAIR, OPTIMZE, ALTER table statements as well as in 
-# LOAD DATA INFILE to empty table
-# it is allocated per thread so be careful with large settings.
+# This buffer is allocated when MySQL needs to rebuild the index in
+# REPAIR, OPTIMZE, ALTER table statements as well as in LOAD DATA INFILE
+# into an empty table. It is allocated per thread so be careful with
+# large settings.
 myisam_sort_buffer_size = 128M
 
-# Maximum size of temporary (sort) file index rebuild  can use.
-# If sort is estimated to take larger amount of space, mush slower
-# (keycache) index rebuild method will be used 
+# The maximum size of the temporary file MySQL is allowed to use while
+# recreating the index (during REPAIR, ALTER TABLE or LOAD DATA INFILE.
+# If the file-size would be bigger than this, the index will be created
+# through the key cache (which is slower).
 myisam_max_sort_file_size = 10G
 
-# Use sort method in case the difference between sort file and 
-# Table index file is estimated to be less than this value
+# If the temporary file used for fast index creation would be bigger
+# than using the key cache by the amount specified here, then prefer the
+# key cache method.  This is mainly used to force long character keys in
+# large tables to use the slower key cache method to create the index.
 myisam_max_extra_sort_file_size = 10G
 
-# If table has more than one index MyISAM can use more than one thread
-# to repair them in parallel. It makes sense if you have multiple of 
-# CPUs and planty of memory.
+# If a table has more than one index, MyISAM can use more than one
+# thread to repair them by sorting in parallel. This makes sense if you
+# have multiple CPUs and plenty of memory.
 myisam_repair_threads = 1
 
-# Automatically check and repair not properly closed MyISAM tables
+# Automatically check and repair not properly closed MyISAM tables.
 myisam_recover
 
 
+# *** BDB Specific options ***
 
-#*** BDB Specific options 
-
-# Use this option if you have BDB tables enabled but you do not plan to use them
+# Use this option if you run a MySQL server with BDB support enabled but
+# you do not plan to use it. This will save memory and may speed up some
+# things.
 skip-bdb
 
 
-#*** INNODB Specific options
+# *** INNODB Specific options ***
 
-# Use this option if you have INNODB tables enabled but you do not plan to use them
+# Use this option if you have a MySQL server with InnoDB support enabled
+# but you do not plan to use it. This will save memory and disk space
+# and speed up some things.
 #skip-innodb
 
-# Additional memory pool is used by Innodb to store metadata information. 
-# If Innodb needs more memory for this purpose to allocate it from OS
-# As it is fast enough on most recent OS you normally do not need to set it higher
-# SHOW INNODB STATUS will show current amount of it in use
+# Additional memory pool that is used by InnoDB to store metadata
+# information.  If InnoDB requires more memory for this purpose it will
+# start to allocate it from the OS.  As this is fast enough on most
+# recent operating systems, you normally do not need to change this
+# value. SHOW INNODB STATUS will display the current amount used.
 innodb_additional_mem_pool_size = 16M
 
-# Innodb, unlike MyISAM uses bufferpool to cache both indexes and row data
-# so you would normally wish to have it large up to 50-70% of your memory size
-# Note on 32bit systems you might be limited to 2-3.5G of user level memory 
-# per process so do not set it too high.
+# InnoDB, unlike MyISAM, uses a buffer pool to cache both indexes and
+# row data. The bigger you set this the less disk I/O is needed to
+# access data in tables. On a dedicated database server you may set this
+# parameter up to 80% of the machine physical memory size. Do not set it
+# too large, though, because competition of the physical memory may
+# cause paging in the operating system.  Note that on 32bit systems you
+# might be limited to 2-3.5G of user level memory per process, so do not
+# set it too high.
 innodb_buffer_pool_size = 2G
 
-# Innodb stores data in one or several files forming tablespace. If you have 
-# single logical drive for your data, single autoextending file would be good enough
-# In other case single file per device is often good choice. 
-# You may setup Innodb to use Raw disk partitions as well. Refer to the manual.
+# InnoDB stores data in one or more data files forming the tablespace.
+# If you have a single logical drive for your data, a single
+# autoextending file would be good enough. In other cases, a single file
+# per device is often a good choice. You can configure InnoDB to use raw
+# disk partitions as well - please refer to the manual for more info
+# about this.
 innodb_data_file_path = ibdata1:10M:autoextend
 
+# Set this option if you would like the InnoDB tablespace files to be
+# stored in another location. By default this is the MySQL datadir.
+#innodb_data_home_dir = <directory>
 
-# Set this option if you would like Innodb tablespace files to be stored in other 
-# location. Default is MySQL datadir.
-#innodb_data_home_dir
-
-# Number of IO threads to use for async IO operations.  This value is hardcoded to
-# 4 on Unix 
+# Number of IO threads to use for async IO operations. This value is
+# hardcoded to 4 on Unix, but on Windows disk I/O may benefit from a
+# larger number.
 innodb_file_io_threads = 4
 
-
-# If you run into Innodb tablespace corruption, setting this to nonzero value will 
-# likely help you to dump your tables. Start from value 1 and increase it until
-# you're able to dump the table successfully.
+# If you run into InnoDB tablespace corruption, setting this to a nonzero
+# value will likely help you to dump your tables. Start from value 1 and
+# increase it until you're able to dump the table successfully.
 #innodb_force_recovery=1
 
-# Number of threads allowed inside of Innodb kernel. Best setting highly depends
-# on the application, hardware as well as OS scheduler properties
-# Too high value may lead to thread thrashing
+# Number of threads allowed inside the InnoDB kernel. The optimal value
+# depends highly on the application, hardware as well as the OS
+# scheduler properties. A too high value may lead to thread thrashing.
 innodb_thread_concurrency = 16
 
-
-# If set to 1 Innodb will flush(fsync) logs to the disk at each transaction commit
-# which offers full ACID behavior, however if you can afford few last commited transaction
-# lost you can set this value to 2 or 0. Innodb will anyway flush the log file once 
-# per second.  0 - do not flush file at all.  2 - flush it to OS buffers but not to the disk.
+# If set to 1, InnoDB will flush (fsync) the transaction logs to the
+# disk at each commit, which offers full ACID behavior. If you are
+# willing to compromise this safety, and you are running small
+# transactions, you may set this to 0 or 2 to reduce disk I/O to the
+# logs. Value 0 means that the log is only written to the log file and
+# the log file flushed to disk approximately once per second. Value 2
+# means the log is written to the log file at each commit, but the log
+# file is only flushed to disk approximately once per second.
 innodb_flush_log_at_trx_commit = 1
 
-
-# Innodb uses fast shutdown by default. However you can disable it to make Innodb to do
-# purge and Insert buffer merge on shutdown. It may increase shutdown time a lot but
-# Innodb will have not need to do it after next startup
+# Speed up InnoDB shutdown. This will disable InnoDB to do a full purge
+# and insert buffer merge on shutdown. It may increase shutdown time a
+# lot, but InnoDB will have to do it on the next startup instead.
 #innodb_fast_shutdown
 
-# Buffer Innodb shall use for buffering log data. As soon as it is full Innodb
-# will have to flush it. As it is flushed once per second anyway even with
-# long transactions it does not make sense to have it very large.
+# The size of the buffer InnoDB uses for buffering log data. As soon as
+# it is full, InnoDB will have to flush it to disk. As it is flushed
+# once per second anyway, it does not make sense to have it very large
+# (even with long transactions). 
 innodb_log_buffer_size = 8M
 
-# Size of log file in group. You shall set combined size of log files large 25%-100% of
-# your buffer pool size to avoid not needed buffer pool flush activity on log file
-# overwrite.  Note however larger logfile size will increase time needed for recovery
-# process.
+# Size of each log file in a log group. You should set the combined size
+# of log files to about 25%-100% of your buffer pool size to avoid
+# unneeded buffer pool flush activity on log file overwrite. However,
+# note that a larger logfile size will increase the time needed for the
+# recovery process.
 innodb_log_file_size = 256M
 
-# Total number of files in the log group. Value 2-3 is usually good enough.
+# Total number of files in the log group. A value of 2-3 is usually good
+# enough.
 innodb_log_files_in_group = 3
 
-# Location for Innodb log files. Default is MySQL datadir.  You may wish to
-# point it to dedicated hard drive or RAID1 volume for improved performance
+# Location of the InnoDB log files. Default is the MySQL datadir. You
+# may wish to point it to a dedicated hard drive or a RAID1 volume for
+# improved performance
 #innodb_log_group_home_dir
 
-# Maximum allowed Percentage of dirty pages in Innodb buffer pool.
-# If it is reached Innodb will start flushing them agressively not to run 
-# out of clean pages at all. This is a soft limit, not guarantied to be held.
+# Maximum allowed percentage of dirty pages in the InnoDB buffer pool.
+# If it is reached, InnoDB will start flushing them out agressively to
+# not run out of clean pages at all. This is a soft limit, not
+# guaranteed to be held.
 innodb_max_dirty_pages_pct = 90
 
-
-# Set flush method Innodb will use for Log.  Tablespace always uses doublewrite flush logic.
-#innodb_flush_method
-
-# How long Innodb transaction shall wait for lock to be granted before giving up.
-# This value does not correspond to deadlock resolution. Innodb will detect Deadlock
-# as soon as it is formed.
+# The flush method InnoDB will use for Log. The tablespace always uses
+# doublewrite flush logic. The default value is "fdatasync", another
+# option is "O_DSYNC".
+#innodb_flush_method=O_DSYNC
+
+# How long an InnoDB transaction should wait for a lock to be granted
+# before being rolled back. InnoDB automatically detects transaction
+# deadlocks in its own lock table and rolls back the transaction. If you
+# use the LOCK TABLES command, or other transaction-safe storage engines
+# than InnoDB in the same transaction, then a deadlock may arise which
+# InnoDB cannot notice. In cases like this the timeout is useful to
+# resolve the situation.
 innodb_lock_wait_timeout = 120
 
 
-
 [mysqldump]
-# Do not buffer whole result set in memory before writing it to file
-# required for dumping very large tables
+# Do not buffer the whole result set in memory before writing it to
+# file. Required for dumping very large tables
 quick
 
 max_allowed_packet = 16M
@@ -444,7 +484,7 @@ max_allowed_packet = 16M
 [mysql]
 no-auto-rehash
 
-# Remove the next comment character if you are not familiar with SQL
+# Only allow UPDATEs and DELETEs that use keys.
 #safe-updates
 
 [isamchk]
@@ -463,7 +503,7 @@ write_buffer = 8M
 interactive-timeout
 
 [mysqld_safe]
-# Increase amount of open files allowed per process
-# Warning: Make sure you have global system limit high enough
-# The high value is required for large number of opened tables
+# Increase the amount of open files allowed per process. Warning: Make
+# sure you have set the global system limit high enough! The high value
+# is required for a large number of opened tables
 open-files-limit = 8192