MultiDataSourceJdbcResource (Hive Metastore Server 4.0.0 API)

java.lang.Object
- org.apache.hadoop.hive.metastore.txn.jdbc.MultiDataSourceJdbcResource

```
public class MultiDataSourceJdbcResource
extends Object
```
Holds multiple DataSources as a single object and offers JDBC related resources. Allows access of the NamedParameterJdbcTemplate, PlatformTransactionManager, Connection objects associated with the registered datasources.

Constructor Summary

Constructors
Constructor and Description
`MultiDataSourceJdbcResource(DatabaseProduct databaseProduct, org.apache.hadoop.conf.Configuration conf, SQLGenerator sqlGenerator)` Creates a new instance of the `MultiDataSourceJdbcResource` class

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`bindDataSource(String dataSourceName)` Binds the current `Thread` to `DataSource` identified by the dataSourceName parameter.
`void`	`bindDataSource(org.springframework.transaction.annotation.Transactional transactional)`
`<T> int`	`execute(InClauseBatchCommand<T> command)` Executes the passed `InClauseBatchCommand`.
`<T> int[][]`	`execute(ParameterizedBatchCommand<T> command)` Executes a `JdbcTemplate.batchUpdate(String, Collection, int, ParameterizedPreparedStatementSetter)` call using the query string obtained from `ParameterizedBatchCommand.getParameterizedQueryString(DatabaseProduct)`, the parameters obtained from `ParameterizedBatchCommand.getQueryParameters()`, and the `PreparedStatementSetter` obtained from `ParameterizedBatchCommand.getPreparedStatementSetter()` methods.
`int`	`execute(ParameterizedCommand command)` Executes a `NamedParameterJdbcTemplate.update(String, org.springframework.jdbc.core.namedparam.SqlParameterSource)` calls using the query string and parameters obtained from `ParameterizedQuery.getParameterizedQueryString(DatabaseProduct)` and `ParameterizedQuery.getQueryParameters()` methods.
`<T> T`	`execute(QueryHandler<T> queryHandler)` Executes a `NamedParameterJdbcTemplate.query(String, SqlParameterSource, ResultSetExtractor)` call using the query string and parameters obtained from `ParameterizedQuery.getParameterizedQueryString(DatabaseProduct)` and `ParameterizedQuery.getQueryParameters()` methods.
`int`	`execute(String query, org.springframework.jdbc.core.namedparam.SqlParameterSource params, Function<Integer,Boolean> resultPolicy)` Executes a `NamedParameterJdbcTemplate.update(String, org.springframework.jdbc.core.namedparam.SqlParameterSource)` calls using the query string and `SqlParameterSource`.
`org.apache.hadoop.conf.Configuration`	`getConf()`
`Connection`	`getConnection()` Returns the `Connection` associated with the current `Thread`.
`DatabaseProduct`	`getDatabaseProduct()`
`org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate`	`getJdbcTemplate()` Returns the `NamedParameterJdbcTemplate` associated with the current `Thread`.
`SQLGenerator`	`getSqlGenerator()`
`TransactionContextManager`	`getTransactionManager()` Returns the `TransactionContextManager` associated with the current `Thread`.
`void`	`registerDataSource(String dataSourceName, DataSource dataSource)` Adds an additional `DataSource` to this instance, specified by its name.
`void`	`unbindDataSource()` Removes the binding between the current `Thread` and the `DataSource`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MultiDataSourceJdbcResource
```
public MultiDataSourceJdbcResource(DatabaseProduct databaseProduct,
                                   org.apache.hadoop.conf.Configuration conf,
                                   SQLGenerator sqlGenerator)
```
    Creates a new instance of the MultiDataSourceJdbcResource class
    
    Parameters:
    
    databaseProduct - A DatabaseProduct instance representing the type of the underlying HMS dabatabe.
- Method Detail
  - registerDataSource
```
public void registerDataSource(String dataSourceName,
                               DataSource dataSource)
```
    Adds an additional DataSource to this instance, specified by its name.
    
    Parameters:
    
    dataSourceName - The name of the DataSource to add.
    
    dataSource - The DataSource to add.
  - bindDataSource
```
public void bindDataSource(String dataSourceName)
```
    Binds the current Thread to DataSource identified by the dataSourceName parameter. Other methods like getConnection(), getJdbcTemplate(), execute(ParameterizedCommand), execute(String, SqlParameterSource, Function), execute(QueryHandler) can be called only after calling this method, and before calling unbindDataSource().
    
    Parameters:
    
    dataSourceName - The name of the DataSource bind to the current Thread.
  - bindDataSource
```
public void bindDataSource(org.springframework.transaction.annotation.Transactional transactional)
```
  - unbindDataSource
```
public void unbindDataSource()
```
    Removes the binding between the current Thread and the DataSource. After calling this method, Other methods like getConnection(), getJdbcTemplate(), execute(ParameterizedCommand), execute(String, SqlParameterSource, Function), execute(QueryHandler) will throw IllegalStateException because it cannot be determined for which DataSource the JDBC resources should be returned.
  - getConf
```
public org.apache.hadoop.conf.Configuration getConf()
```
    Returns:
    
    Returns the Configuration object used to create this MultiDataSourceJdbcResource instance.
  - getSqlGenerator
```
public SQLGenerator getSqlGenerator()
```
  - getJdbcTemplate
```
public org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate getJdbcTemplate()
```
    Returns the NamedParameterJdbcTemplate associated with the current Thread. Can be called only after bindDataSource(String) and before unbindDataSource(). Ensures that the same instance is returned all the time.
    
    Throws:
    
    IllegalStateException - Thrown when there is no bound DataSource.
  - getConnection
```
public Connection getConnection()
```
    Returns the Connection associated with the current Thread. Can be called only after bindDataSource(String) and before unbindDataSource(). Ensures that the same instance is returned all the time.
    
    Throws:
    
    IllegalStateException - Thrown when there is no bound DataSource.
  - getTransactionManager
```
public TransactionContextManager getTransactionManager()
```
    Returns the TransactionContextManager associated with the current Thread. Can be called only after bindDataSource(String) and before unbindDataSource(). Ensures that the same instance is returned all the time.
    
    Throws:
    
    IllegalStateException - Thrown when there is no bound DataSource.
  - getDatabaseProduct
```
public DatabaseProduct getDatabaseProduct()
```
    Returns:
    
    Returns a DatabaseProduct instance representing the type of the underlying HMS dabatabe.
  - execute
```
public int execute(ParameterizedCommand command)
            throws MetaException
```
    Executes a NamedParameterJdbcTemplate.update(String, org.springframework.jdbc.core.namedparam.SqlParameterSource) calls using the query string and parameters obtained from ParameterizedQuery.getParameterizedQueryString(DatabaseProduct) and ParameterizedQuery.getQueryParameters() methods. Validates the resulted number of affected rows using the ParameterizedCommand.resultPolicy() function.
    
    Parameters:
    
    command - The ParameterizedCommand to execute.
    
    Returns:
    
    Returns the number of affected rows.
    
    Throws:
    
    MetaException - Forwarded from ParameterizedQuery.getParameterizedQueryString(DatabaseProduct) or thrown if the update count was rejected by the ParameterizedCommand.resultPolicy() method
  - execute
```
public <T> int[][] execute(ParameterizedBatchCommand<T> command)
                    throws MetaException
```
    Executes a JdbcTemplate.batchUpdate(String, Collection, int, ParameterizedPreparedStatementSetter) call using the query string obtained from ParameterizedBatchCommand.getParameterizedQueryString(DatabaseProduct), the parameters obtained from ParameterizedBatchCommand.getQueryParameters(), and the PreparedStatementSetter obtained from ParameterizedBatchCommand.getPreparedStatementSetter() methods. The batchSize is coming from the Configuration object.
    
    Parameters:
    
    command - The ParameterizedBatchCommand to execute.
    
    Throws:
    
    MetaException
  - execute
```
public <T> int execute(InClauseBatchCommand<T> command)
                throws MetaException
```
    Executes the passed InClauseBatchCommand. It estimates the length of the query and if it exceeds the limit set in MetastoreConf.ConfVars.DIRECT_SQL_MAX_QUERY_LENGTH, or the number of elements in the IN() clause exceeds MetastoreConf.ConfVars.DIRECT_SQL_MAX_ELEMENTS_IN_CLAUSE, the query will be split to multiple queries.
    
    Type Parameters:
    
    T - The type of the elements in the IN() clause
    
    Parameters:
    
    command - The InClauseBatchCommand to execute
    
    Returns:
    
    Returns with the number of affected rows in total.
    
    Throws:
    
    MetaException - If InClauseBatchCommand.getInClauseParameterName() is blank, or the value of the IN() clause parameter in InClauseBatchCommand.getQueryParameters() is not exist or not an instance of List<T>
  - execute
```
public int execute(String query,
                   org.springframework.jdbc.core.namedparam.SqlParameterSource params,
                   Function<Integer,Boolean> resultPolicy)
            throws MetaException
```
    Executes a NamedParameterJdbcTemplate.update(String, org.springframework.jdbc.core.namedparam.SqlParameterSource) calls using the query string and SqlParameterSource. Validates the resulted number of affected rows using the resultpolicy function.
    
    Parameters:
    
    query - Parameterized query string.
    
    params - Qyery parameters
    
    resultPolicy - Result policy to use, or null, if no result policy.
    
    Returns:
    
    Returns the number of affected rows.
    
    Throws:
    
    MetaException - Forwarded from ParameterizedQuery.getParameterizedQueryString(DatabaseProduct) or thrown if the update count was rejected by the ParameterizedCommand.resultPolicy() method
  - execute
```
public <T> T execute(QueryHandler<T> queryHandler)
              throws MetaException
```
    Executes a NamedParameterJdbcTemplate.query(String, SqlParameterSource, ResultSetExtractor) call using the query string and parameters obtained from ParameterizedQuery.getParameterizedQueryString(DatabaseProduct) and ParameterizedQuery.getQueryParameters() methods. Processes the result using the ResultSetExtractor.extractData(ResultSet) method (QueryHandler extends the ResultSetExtractor interface).
    
    Parameters:
    
    queryHandler - The QueryHandler instance containing the query, SqlParameterSource, and ResultSetExtractor.
    
    Returns:
    
    Returns with the object(s) constructed from the result of the executed query.
    
    Throws:
    
    MetaException - Forwarded from ParameterizedQuery.getParameterizedQueryString(DatabaseProduct).

Class MultiDataSourceJdbcResource

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

MultiDataSourceJdbcResource

Method Detail

registerDataSource

bindDataSource

bindDataSource

unbindDataSource

getConf

getSqlGenerator

getJdbcTemplate

getConnection

getTransactionManager

getDatabaseProduct

execute

execute

execute

execute

execute