En el fichero custom-hibernate-dialect.properties y la única línea que está descomentada es la de mysql, que es la base de datos que estoy utilizando. Por otra parte el fichero custom-repository.properties está configurado como sigue:
#
# Sample custom content and index data location
#
dir.root=/opt/alfresco/alf_data
#
# Sample database connection properties
#
db.username=alfresco
db.password=alfresco
db.pool.initial=10
db.pool.max=100
#
# Activate index tracking and recovery
#
#index.tracking.cronExpression=0/5 * * * * ?
#index.recovery.mode=AUTO
#
# Property to control whether schema updates are performed automatically.
# Updates must be enabled during upgrades as, apart from the static upgrade scripts,
# there are also auto-generated update scripts that will need to be executed. After
# upgrading to a new version, this can be disabled.
#
#db.schema.update=true
#
# Derby connection
#
#db.driver=org.apache.derby.jdbc.EmbeddedDriver
#db.url=jdbc:derby:/opt/alfresco/alf_data/derby_data/alfresco;create=true
#
# MySQL connection (This is default and requires mysql-connector-java-5.0.3-bin.jar, which ships with the Alfresco server)
#
db.driver=org.gjt.mm.mysql.Driver
db.url=jdbc:mysql://localhost/alfresco
#
# Oracle connection
#
#db.driver=oracle.jdbc.OracleDriver
#db.url=jdbc
racle:thin:@localhost:1521:alfresco
#
# SQLServer connection (note you must enable TCP protocol on fixed port 1433)
#
#db.driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
#db.url=jdbc:sqlserver://localhost:1433;databaseName=alfresco
# The well known RMI registry port is defined in the alfresco-shared.properties file
# alfresco.rmi.services.port=50500
#
# RMI service ports for the individual services.
# These six services are available remotely.
#
# Assign individual ports for each service for best performance
# or run several services on the same port. You can even run everything on 50500 if needed.
#
# Select 0 to use a random unused port.
#
#avm.rmi.service.port=50501
#avmsync.rmi.service.port=50502
#attribute.rmi.service.port=50503
#authentication.rmi.service.port=50504
#repo.rmi.service.port=50505
#action.rmi.service.port=50506
#
# Sample custom content and index data location
#
dir.root=/opt/alfresco/alf_data
#
# Sample database connection properties
#
db.username=alfresco
db.password=alfresco
db.pool.initial=10
db.pool.max=100
#
# Activate index tracking and recovery
#
#index.tracking.cronExpression=0/5 * * * * ?
#index.recovery.mode=AUTO
#
# Property to control whether schema updates are performed automatically.
# Updates must be enabled during upgrades as, apart from the static upgrade scripts,
# there are also auto-generated update scripts that will need to be executed. After
# upgrading to a new version, this can be disabled.
#
#db.schema.update=true
#
# Derby connection
#
#db.driver=org.apache.derby.jdbc.EmbeddedDriver
#db.url=jdbc:derby:/opt/alfresco/alf_data/derby_data/alfresco;create=true
#
# MySQL connection (This is default and requires mysql-connector-java-5.0.3-bin.jar, which ships with the Alfresco server)
#
db.driver=org.gjt.mm.mysql.Driver
db.url=jdbc:mysql://localhost/alfresco
#
# Oracle connection
#
#db.driver=oracle.jdbc.OracleDriver
#db.url=jdbc
racle:thin:@localhost:1521:alfresco#
# SQLServer connection (note you must enable TCP protocol on fixed port 1433)
#
#db.driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
#db.url=jdbc:sqlserver://localhost:1433;databaseName=alfresco
# The well known RMI registry port is defined in the alfresco-shared.properties file
# alfresco.rmi.services.port=50500
#
# RMI service ports for the individual services.
# These six services are available remotely.
#
# Assign individual ports for each service for best performance
# or run several services on the same port. You can even run everything on 50500 if needed.
#
# Select 0 to use a random unused port.
#
#avm.rmi.service.port=50501
#avmsync.rmi.service.port=50502
#attribute.rmi.service.port=50503
#authentication.rmi.service.port=50504
#repo.rmi.service.port=50505
#action.rmi.service.port=50506
