Oracle dialect

Supported database versions

SQL persistence supports Oracle 11g Release 2 and above.

Usage

Using the Oracle.ManagedDataAccess NuGet Package.

var connection = "Data Source=localhost;User Id=username;Password=pass;Enlist=false;";
var persistence = endpointConfiguration.UsePersistence<SqlPersistence>();
var subscriptions = persistence.SubscriptionSettings();
subscriptions.CacheFor(TimeSpan.FromMinutes(1));
persistence.SqlDialect<SqlDialect.Oracle>();
persistence.ConnectionBuilder(
    connectionBuilder: () =>
    {
        return new OracleConnection(connection);
    });

In Versions 2.2.0 and above it's possible to specify custom schema using the following code:

var persistence = endpointConfiguration.UsePersistence<SqlPersistence>();
persistence.SqlVariant(SqlVariant.Oracle);
persistence.Schema("custom_schema");

Unicode support

SQL persistence itself supports Unicode characters, however data may become corrupted during saving if the database settings are incorrect. If Unicode support is required, follow the guidelines for each database engine. In particular set the correct character set and collation for databases storing persistence data.

Refer to the dedicated Oracle documentation for details.

Schema support

The notion of schemas is slightly different than in other databases, notably SQL Server and PostgreSQL. By default, when schema is not specified, SQL persistence uses the context of the logged-in user when referring to database objects. When a schema is specified, that schema is used instead of the logged-in user when referring to database tables.

var persistence = endpointConfiguration.UsePersistence<SqlPersistence>();
var dialect = persistence.SqlDialect<SqlDialect.Oracle>();
dialect.Schema("MySchema");

Supported name lengths

SQL persistence automatically generates names of database objects such as tables, indexes and procedures used internally. Every database engine has its own rules and limitations regarding maximum allowed name length.

The SQL Persistence provides autonomy between endpoints by using separate tables for each endpoint based on the endpoint name. However, due to Oracle's 30-character limit on table names and index names in Oracle 12.1 and below, the SQL Persistence must make some compromises.

Table Names

For storing subscriptions, timeouts, and outbox data, SQL Persistence will reserve 24 characters for the endpoint name, leaving 3 characters for the persistence type, and additional 3 characters for an index type. Names are then constructed as {EndpointName}{PersistenceTypeSuffix}{KeyType}.

The following table shows table names created for an endpoint named My.Endpoint:

If an endpoint name is longer than 24 characters, an exception will be thrown, and a substitute table prefix must be specified in the endpoint configuration:

var persistence = endpointConfiguration.UsePersistence<SqlPersistence>();
persistence.TablePrefix("ThePrefix");

Sagas

Tables generated for sagas reserve 27 characters for the saga name, leaving 3 characters for the _PK suffix for the table's primary key.

To accommodate as many characters for the saga name as possible, the table prefix is omitted from the saga table name.

A 3-character suffix is not enough to uniquely identify multiple correlation properties in a deterministic way, so unfortunately index names for sagas cannot be named after the owner table in the same way as for other persistence types.

Index names for correlation properties are constructed using the prefix SAGAIDX_ plus a deterministic hash of the saga name and correlation property name. The owning table for a particular index can be discovered by querying the database:

select TABLE_NAME
from ALL_INDEXES
where INDEX_NAME = 'SAGAIDX_525D1D4DC0C3DCD96947E1';

If a saga name is longer than 27 characters, an exception will be thrown, and a substitute table name must be specified.

Custom Finders

Because Oracle 11g does not support any JSON query capability, custom saga finders that locate saga data by querying into the JSON payload of the saga are not supported by SQL Persistence when using Oracle.