Banco de dados multiuser

Raul_Kl disse:

Se o servidor do banco de dados for Windows, eu recomendo o SQL Server.

Existem várias versões, e você pode escolher uma de acordo com suas necessidades e verba disponível.

A versão Express é gratuita, suporta até 10 GB de dados e usa até 1 GB de RAM do servidor. Para bancos de dados mais "pesados" existem as versões pagas.

Existem também opções livres, como por exemplo o Postgres. Este pode ser instalado tanto em servidores Windows quanto *NIX.

Raul_Kl disse:

Tanto o SQL Server como o Postgres precisam ser instalados apenas no servidor.
Ambos são multi usuário e podem trabalhar com várias operações de leitura e escrita simultaneamente.

Nunca trabalhei com VB.NET, mas acredito que seja bem simples fazer a conexão com o banco de dados remoto, assim como é com C#.NET ou outras linguagens.

intruso disse:

Ta com cara que você digitou o nome da maquina ou instância errada...

Também pode ser que a maquina onde está instalado o serviço não esteja na mesma rede, ou firewall barrando ...

Raul_Kl disse:

A aplicação e o banco de dados estão no mesmo servidor, ou estão em máquinas separadas?

Se o MySQL não estiver na mesma máquina em que está a aplicação, além de abrir a porta no firewall é necessário configurá-lo para permitir acesso remoto.

GRANT ALL ON nome_do_banco.* TO 'usuario'@'%' IDENTIFIED BY 'senha'; FLUSH PRIVILEGES;

Raul_Kl disse:

Ainda não entendi bem como funciona a aplicação, mas se for problema de acesso remoto ao banco de dados, verifique a linha "bind-address = " do arquivo my.ini(Windows) ou my.cnf(Linux). Se estiver com o valor "127.0.0.1" altere para "0.0.0.0".

Também é necessário dar permissão de acesso remoto ao usuário que conecta no banco de dados usando o terminal do MySQL:

GRANT ALL ON nome_do_banco.* TO 'usuario'@'%' IDENTIFIED BY 'senha'; FLUSH PRIVILEGES;

Depois disso, é necessário reiniciar o serviço do MySQL.

Raul_Kl disse:

Ainda não entendi bem como funciona a aplicação, mas se for problema de acesso remoto ao banco de dados, verifique a linha "bind-address = " do arquivo my.ini(Windows) ou my.cnf(Linux). Se estiver com o valor "127.0.0.1" altere para "0.0.0.0".

Também é necessário dar permissão de acesso remoto ao usuário que conecta no banco de dados usando o terminal do MySQL:

GRANT ALL ON nome_do_banco.* TO 'usuario'@'%' IDENTIFIED BY 'senha'; FLUSH PRIVILEGES;

Depois disso, é necessário reiniciar o serviço do MySQL.

 # MySQL Server Instance Configuration File# ----------------------------------------------------------------------

# Generated by the MySQL Server Instance Configuration Wizard

#

#

# Installation Instructions

# ----------------------------------------------------------------------

#

# On Linux 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.

#

# On Windows you should keep this file in the installation directory 

# of your server (e.g. C:\Program Files\MySQL\MySQL Server X.Y). To

# make sure the server reads the config file use the startup option 

# "--defaults-file". 

#

# To run run the server from the command line, execute this in a 

# command line shell, e.g.

# mysqld --defaults-file="C:\Program Files\MySQL\MySQL Server X.Y\my.ini"

#

# To install the server as a Windows service manually, execute this in a 

# command line shell, e.g.

# mysqld --install MySQLXY --defaults-file="C:\Program Files\MySQL\MySQL Server X.Y\my.ini"

#

# And then execute this in a command line shell to start the server, e.g.

# net start MySQLXY

#

#

# Guildlines for editing this file

# ----------------------------------------------------------------------

#

# In this file, you can use all long options that the program supports.

# If you want to know the options a program supports, start the program

# with the "--help" option.

#

# More detailed information about the individual options can also be

# found in the manual.

#

#

# CLIENT SECTION

# ----------------------------------------------------------------------

#

# 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]



port=3306



[mysql]



default-character-set=latin1





# SERVER SECTION

# ----------------------------------------------------------------------

#

# The following options will be read by the MySQL Server. Make sure that

# you have installed the server correctly (see above) so it reads this 

# file.

#

[mysqld]



# The TCP/IP Port the MySQL Server will listen on

port=3306





#Path to installation directory. All paths are usually resolved relative to this.

basedir="C:/Program Files/MySQL/MySQL Server 5.5/"



#Path to the database root

datadir="C:/ProgramData/MySQL/MySQL Server 5.5/Data/"



# The default character set that will be used when a new schema or table is

# created and no character set is defined

character-set-server=latin1



# The default storage engine that will be used when create new tables when

default-storage-engine=INNODB



# Set the SQL mode to strict

sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"



# 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



# 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=0



# 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=256



# 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=34M





# 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_size=8



#*** MyISAM Specific options



# 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=100G



# 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_sort_buffer_size=67M



# 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=53M



# 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=64K

read_rnd_buffer_size=256K



# 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.

sort_buffer_size=256K





#*** INNODB Specific options ***





# 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 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=3M



# 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



# 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=2M



# 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=103M



# 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=52M



# 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=10

suzart.bruno disse:

Não encontrei o bind-adress no my.ini