CData Cloud offers access to Greenplum across several standard services and protocols, in a cloud-hosted solution. Any application that can connect to a MySQL or SQL Server database can connect to Greenplum through CData Cloud.
CData Cloud allows you to standardize and configure connections to Greenplum as though it were any other OData endpoint, or standard SQL Server/MySQL database.
This page provides a guide to Establishing a Connection to Greenplum in CData Cloud, as well as information on the available resources, and a reference to the available connection properties.
Establishing a Connection shows how to authenticate to Greenplum and configure any necessary connection properties to create a database in CData Cloud
Accessing data from Greenplum through the available standard services and CData Cloud administration is documented in further details in the CData Cloud Documentation.
Connect to Greenplum by selecting the corresponding icon in the Database tab. Required properties are listed under Settings. The Advanced tab lists connection properties that are not typically required.
To connect to Greenplum, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you want to use to authenticate to the server. If the Database property is not specified, the Cloud connects to the user's default database (it is the same name as the user).
The specific authentication method is setup in the pg_hba.conf file on the Greenplum Server. You can find instructions about authentication setup on the Greenplum Server here. The md5, password and SASL authentication methods do not require additional setup by the CData Cloud.
The Greenplum Server initiates authentication with the Kerberos Server when the CData Cloud attempts a connection. You need to setup Kerberos on the Greenplum Server to activate this authentication method. After you have Kerberos authentication setup on the Greenplum Server, see Using Kerberos for details on how to authenticate with Kerberos by the Cloud.
Authenticating to Greenplum via Kerberos requires you to define authentication properties and to choose how Kerberos should retrieve authentication tickets.
The Cloud provides three ways to retrieve the required Kerberos ticket, depending on whether or not the KRB5CCNAME and/or KerberosKeytabFile variables exist in your environment.
MIT Kerberos Credential Cache File
This option enables you to use the MIT Kerberos Ticket Manager or kinit command to get tickets. With this option there is no need to set the User or Password connection properties.
This option requires that KRB5CCNAME has been created in your system.
To enable ticket retrieval via MIT Cerberos Credential Cache Files:
If the ticket is successfully obtained, the ticket information appears in Kerberos Ticket Manager and is stored in the credential cache file.
The Cloud uses the cache file to obtain the Kerberos ticket to connect to Greenplum.
Note: If you would prefer not to edit KRB5CCNAME, you can use the KerberosTicketCache property to set the file path manually. After this is set, the Cloud uses the specified cache file to obtain the Kerberos ticket to connect to Greenplum.
Keytab File
If your environment lacks the KRB5CCNAME environment variable, you can retrieve a Kerberos ticket using a Keytab File.
To use this method, set the User property to the desired username, and set the KerberosKeytabFile property to a file path pointing to the keytab file associated with the user.
User and Password
If your environment lacks the KRB5CCNAME environment variable and the KerberosKeytabFile property has not been set, you can retrieve a ticket using a user and password combination.
To use this method, set the User and Password properties to the user/password combination that you use to authenticate with Greenplum.
To enable this kind of cross-realm authentication, set the KerberosRealm and KerberosKDC properties to the values required for user authentication. Also, set the KerberosServiceRealm and KerberosServiceKDC properties to the values required to obtain the service ticket.
By default, the Cloud attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store.
To specify another certificate, see the SSLServerCert property for the available formats to do so.
The Greenplum Cloud also supports setting client certificates. Set the following to connect using a client certificate.
Set the following properties:
The connection string properties are the various options that can be used to establish a connection. This section provides a complete list of the options you can configure in the connection string for this provider. Click the links for further details.
For more information on establishing a connection, see Establishing a Connection.
| Property | Description |
| Server | The host name or IP address of the server. |
| Port | The port number of the Greenplum server. |
| Database | The name of the Greenplum database. |
| User | The Greenplum user account used to authenticate. |
| Password | The password used to authenticate the user. |
| UseSSL | This field sets whether SSL is enabled. |
| Property | Description |
| SSLServerCert | The certificate to be accepted from the server when connecting using TLS/SSL. |
| Property | Description |
| SSHAuthMode | The authentication method used when establishing an SSH Tunnel to the service. |
| SSHClientCert | A certificate to be used for authenticating the SSHUser. |
| SSHClientCertPassword | The password of the SSHClientCert key if it has one. |
| SSHClientCertSubject | The subject of the SSH client certificate. |
| SSHClientCertType | The type of SSHClientCert private key. |
| SSHServer | The SSH server. |
| SSHPort | The SSH port. |
| SSHUser | The SSH user. |
| SSHPassword | The SSH password. |
| SSHServerFingerprint | The SSH server fingerprint. |
| UseSSH | Whether to tunnel the Greenplum connection over SSH. Use SSH. |
| Property | Description |
| Verbosity | The verbosity level that determines the amount of detail included in the log file. |
| Property | Description |
| BrowsableSchemas | This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC. |
| Property | Description |
| AllowPreparedStatement | Prepare a query statement before its execution. |
| FetchResultSetMetadata | This field sets whether the provider retrieves metadata pertaining to the schema and table name for resultset columns returned by the server. |
| MaxRows | Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses. |
| SupportUnboundedColumns | When this property is set, the provider reports Int32.MaxValue as the size of the columns of data type 'bytea' and 'text'. |
| Timeout | The value in seconds until the timeout error is thrown, canceling the operation. |
This section provides a complete list of the Authentication properties you can configure in the connection string for this provider.
| Property | Description |
| Server | The host name or IP address of the server. |
| Port | The port number of the Greenplum server. |
| Database | The name of the Greenplum database. |
| User | The Greenplum user account used to authenticate. |
| Password | The password used to authenticate the user. |
| UseSSL | This field sets whether SSL is enabled. |
The host name or IP address of the server.
string
""
The host name or IP of the server hosting the Greenplum Database. If not set, the default value "localhost" is used.
The name of the Greenplum database.
string
""
The database to connect to when connecting to the Greenplum Server. If a database is not provided, the user's default database will be used.
The Greenplum user account used to authenticate.
string
""
Together with Password, this field is used to authenticate against the Greenplum server.
The password used to authenticate the user.
string
""
The User and Password are together used to authenticate with the server.
This field sets whether SSL is enabled.
bool
false
This field sets whether the Cloud will attempt to negotiate TLS/SSL connections to the server. By default, the Cloud checks the server's certificate against the system's trusted certificate store. To specify another certificate, set SSLServerCert.
This section provides a complete list of the SSL properties you can configure in the connection string for this provider.
| Property | Description |
| SSLServerCert | The certificate to be accepted from the server when connecting using TLS/SSL. |
The certificate to be accepted from the server when connecting using TLS/SSL.
string
""
If using a TLS/SSL connection, this property can be used to specify the TLS/SSL certificate to be accepted from the server. Any other certificate that is not trusted by the machine is rejected.
This property can take the following forms:
| Description | Example |
| A full PEM Certificate (example shortened for brevity) | -----BEGIN CERTIFICATE----- MIIChTCCAe4CAQAwDQYJKoZIhv......Qw== -----END CERTIFICATE----- |
| A path to a local file containing the certificate | C:\cert.cer |
| The public key (example shortened for brevity) | -----BEGIN RSA PUBLIC KEY----- MIGfMA0GCSq......AQAB -----END RSA PUBLIC KEY----- |
| The MD5 Thumbprint (hex values can also be either space or colon separated) | ecadbdda5a1529c58a1e9e09828d70e4 |
| The SHA1 Thumbprint (hex values can also be either space or colon separated) | 34a929226ae0819f2ec14b4a3d904f801cbb150d |
If not specified, any certificate trusted by the machine is accepted.
Use '*' to signify to accept all certificates. Note that this is not recommended due to security concerns.
This section provides a complete list of the SSH properties you can configure in the connection string for this provider.
| Property | Description |
| SSHAuthMode | The authentication method used when establishing an SSH Tunnel to the service. |
| SSHClientCert | A certificate to be used for authenticating the SSHUser. |
| SSHClientCertPassword | The password of the SSHClientCert key if it has one. |
| SSHClientCertSubject | The subject of the SSH client certificate. |
| SSHClientCertType | The type of SSHClientCert private key. |
| SSHServer | The SSH server. |
| SSHPort | The SSH port. |
| SSHUser | The SSH user. |
| SSHPassword | The SSH password. |
| SSHServerFingerprint | The SSH server fingerprint. |
| UseSSH | Whether to tunnel the Greenplum connection over SSH. Use SSH. |
The authentication method used when establishing an SSH Tunnel to the service.
string
"Password"
A certificate to be used for authenticating the SSHUser.
string
""
SSHClientCert must contain a valid private key in order to use public key authentication. A public key is optional, if one is not included then the Cloud generates it from the private key. The Cloud sends the public key to the server and the connection is allowed if the user has authorized the public key.
The SSHClientCertType field specifies the type of the key store specified by SSHClientCert. If the store is password protected, specify the password in SSHClientCertPassword.
Some types of key stores are containers which may include multiple keys. By default the Cloud will select the first key in the store, but you can specify a specific key using SSHClientCertSubject.
The password of the SSHClientCert key if it has one.
string
""
This property is only used when authenticating to SFTP servers with SSHAuthMode set to PublicKey and SSHClientCert set to a private key.
The subject of the SSH client certificate.
string
"*"
When loading a certificate the subject is used to locate the certificate in the store.
If an exact match is not found, the store is searched for subjects containing the value of the property.
If a match is still not found, the property is set to an empty string, and no certificate is selected.
The special value "*" picks the first certificate in the certificate store.
The certificate subject is a comma separated list of distinguished name fields and values. For instance "CN=www.server.com, OU=test, C=US, [email protected]". Common fields and their meanings are displayed below.
| Field | Meaning |
| CN | Common Name. This is commonly a host name like www.server.com. |
| O | Organization |
| OU | Organizational Unit |
| L | Locality |
| S | State |
| C | Country |
| E | Email Address |
If a field value contains a comma it must be quoted.
The type of SSHClientCert private key.
string
"PEMKEY_FILE"
This property can take one of the following values:
| Types | Description | Allowed Blob Values |
| MACHINE/USER | Blob values are not supported. | |
| JKSFILE/JKSBLOB | base64-only | |
| PFXFILE/PFXBLOB | A PKCS12-format (.pfx) file. Must contain both a certificate and a private key. | base64-only |
| PEMKEY_FILE/PEMKEY_BLOB | A PEM-format file. Must contain an RSA, DSA, or OPENSSH private key. Can optionally contain a certificate matching the private key. | base64 or plain text. Newlines may be replaced with spaces when providing the blob as text. |
| PPKFILE/PPKBLOB | A PuTTY-format private key created using the puttygen tool. | base64-only |
| XMLFILE/XMLBLOB | An XML key in the format generated by the .NET RSA class: RSA.ToXmlString(true). | base64 or plain text. |
The SSH server.
string
""
The SSH server.
The SSH port.
string
"22"
The SSH port.
The SSH user.
string
""
The SSH user.
The SSH password.
string
""
The SSH password.
The SSH server fingerprint.
string
""
The SSH server fingerprint.
Whether to tunnel the Greenplum connection over SSH. Use SSH.
bool
false
By default the Cloud will attempt to connect directly to Greenplum. When this option is enabled, the Cloud will instead establish an SSH connection with the SSHServer and tunnel the connection to Greenplum through it.
This section provides a complete list of the Logging properties you can configure in the connection string for this provider.
| Property | Description |
| Verbosity | The verbosity level that determines the amount of detail included in the log file. |
The verbosity level that determines the amount of detail included in the log file.
string
"1"
The verbosity level determines the amount of detail that the Cloud reports to the Logfile. Verbosity levels from 1 to 5 are supported. These are detailed in the Logging page.
This section provides a complete list of the Schema properties you can configure in the connection string for this provider.
| Property | Description |
| BrowsableSchemas | This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC. |
This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC.
string
""
Listing the schemas from databases can be expensive. Providing a list of schemas in the connection string improves the performance.
This section provides a complete list of the Miscellaneous properties you can configure in the connection string for this provider.
| Property | Description |
| AllowPreparedStatement | Prepare a query statement before its execution. |
| FetchResultSetMetadata | This field sets whether the provider retrieves metadata pertaining to the schema and table name for resultset columns returned by the server. |
| MaxRows | Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses. |
| SupportUnboundedColumns | When this property is set, the provider reports Int32.MaxValue as the size of the columns of data type 'bytea' and 'text'. |
| Timeout | The value in seconds until the timeout error is thrown, canceling the operation. |
Prepare a query statement before its execution.
bool
true
If the AllowPreparedStatement property is set to false, statements are parsed each time they are executed. Setting this property to false can be useful if you are executing many different queries only once.
If you are executing the same query repeatedly, you will generally see better performance by leaving this property at the default, true. Preparing the query avoids recompiling the same query over and over. However, prepared statements also require the Cloud to keep the connection active and open while the statement is prepared.
This field sets whether the provider retrieves metadata pertaining to the schema and table name for resultset columns returned by the server.
bool
false
By default, the Cloud will not request that the server provides detailed information about resultset columns like the table name or schema name. It requires issuing additional metadata queries via Cloud , and it may affect query performance essentially in some scenarios. Consider setting this property to True when you need such detailed descriptive information for the resultset columns.
Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.
int
-1
Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.
When this property is set, the provider reports Int32.MaxValue as the size of the columns of data type 'bytea' and 'text'.
bool
true
When false, columns of data type 'text' will report a size of DefaultColumnSize.
The value in seconds until the timeout error is thrown, canceling the operation.
int
30
If Timeout = 0, operations do not time out. The operations run until they complete successfully or until they encounter an error condition.
If Timeout expires and the operation is not yet complete, the Cloud throws an exception.