When using DatabaseBuilder.readOnlyDatabase(true) then
ebean will:
- Set the DataSourceBuilder to use autoCommit=true and readOnly=true
- Use the same DataSource instance for both dataSource and readOnlyDataSource
This is to simplify the setup/configuration for creating a Database that
will only have read-only use.
Note that readOnly=true is a JDBC hint and for example H2 database effectively
ignores that hint where as Postgres will enforce the read-only true nature.
That is, existing code using DataSourceConfig has access to the getter
methods of DataSourceConfig. The DataSourceBuilder interface only has
the setter methods and DataSourceBuilder.Settings has both getters and
setter methods.
That is, the refactor to extract the DataSourceBuilder interface also
split off the getter methods to the DataSourceBuilder.Settings interface
(because most of the time when using the builder we only need the
setter methods and effectively hiding the getter methods behind the settings()
is useful to simplify the API for users).
So DatabaseBuilder.Settings has all the getters for code looking to read
the configuration that has been set. So DatabaseBuilder now just has the
setter methods.
Use DatabaseBuilder.settings() to access the settings and read the config
that has been set.
First step in migrating the ebean-datasource API to use builder pattern.
DataSourceConfig (concrete type) migrating to DataSourceBuilder (interface).
A followup step will deprecate the use of DataSourceConfig.
- The error reported was that a DataSource connection pool maxed out
- The symptom was that there was an additional lazy loading queries invoked via the hashCode/equals implementation of ManyToMany Set.
- The fix is for BeanSet init() to lazy load with onlyIds = false, that avoids the extra lazy loading query from being executed
The filterMany( <string expressions> ) uses the language parser which
ultimately will we probably remove in ebean 15.x
Code can migrate to filterManyRaw() instead or better yet change to
use the improved query beans filterMany( <closure> ) option that will
be included in this same ebean release.
Query beans also generate a "Assoc" query bean that is used
for the relationships. Previously these were generated into a
.query.assoc package and with this they are generated as an
inner class of the query bean.
This then allows the change where an additional filterMany()
is generated on the "Assoc" bean that takes a closure. This
simplifies the use of query beans for filterMany.
This change to the generated query beans needs a change to the
ebean-agent enhancement.
When we have a read replica with potential for replication lag, and config a read only DataSource to use that read replica, by default a query executed without a current transaction will use the read replica.
We specify usingMaster() when we explicitly want to execute a query and use the master data source.
Rob Bygrave