Connection String Parameters for Impala
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.
| Name | Description |
| AuthScheme | The authentication scheme used. Accepted entries are NOSASL, LDAP and KERBEROS. |
| AutoCache | Automatically caches the results of SELECT queries into a cache database specified by either CacheLocation or both of CacheConnection and CacheProvider . |
| CacheConnection | The connection string for the cache database. This property is always used in conjunction with CacheProvider . Setting both properties will override the value set for CacheLocation for caching data. |
| CacheLocation | Specifies the path to the cache when caching to a file. |
| CacheMetadata | This property determines whether or not to cache the table metadata to a file store. |
| CacheProvider | The name of the provider to be used to cache data. |
| CacheTolerance | The tolerance for stale data in the cache specified in seconds when using AutoCache . |
| ConnectionLifeTime | The maximum lifetime of a connection in seconds. Once the time has elapsed, the connection object is disposed. |
| Database | The name of the Impala database to use by default. |
| KerberosKeytabFile | The Keytab file containing your pairs of Kerberos principals and encrypted keys. |
| Location | A path to the directory that contains the schema files defining tables, views, and stored procedures. |
| Logfile | A path to the log file. |
| MaxLogFileCount | A string specifying the maximum file count of log files. When the limit is hit, a new log is created in the same folder with the date and time appended to the end and the oldest log file will be deleted. |
| MaxLogFileSize | A string specifying the maximum size in bytes for a log file (for example, 10 MB). When the limit is hit, a new log is created in the same folder with the date and time appended to the end. |
| MaxRows | Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time. |
| Offline | Use offline mode to get the data from the cache instead of the live source. |
| Other | These hidden properties are used only in specific use cases. |
| PageSize | The number of results to return per request from Impala. |
| Password | The password used to authenticate with Impala. |
| PoolIdleTimeout | The allowed idle time for a connection before it is closed. |
| PoolMaxSize | The maximum connections in the pool. |
| PoolMinSize | The minimum number of connections in the pool. |
| PoolWaitTime | The max seconds to wait for an available connection. |
| Port | The port for the connection to the Impala Server instance. |
| ProtocolVersion | The Thrift protocol version to use when connecting to the Impala server. |
| PseudoColumns | This property indicates whether or not to include pseudo columns as columns to the table. |
| QueryPassthrough | This option passes the query to the Apache Impala server as is. |
| Readonly | You can use this property to enforce read-only access to Apache Impala from the provider. |
| RTK | The runtime key used for licensing. |
| Server | The name of the server running SQL Server. |
| SupportEnhancedSQL | This property enhances SQL functionality beyond what can be supported through the API directly, by enabling in-memory client-side processing. |
| Tables | This property restricts the tables reported to a subset of the available tables. For example, Tables=TableA,TableB,TableC. |
| UseConnectionPooling | This property enables connection pooling. |
| User | The username used to authenticate with Impala. |
| Verbosity | The verbosity level that determines the amount of detail included in the log file. |
| Views | Restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC. |