mondrian.spi.impl

Class GreenplumDialect

java.lang.Object

mondrian.spi.impl.JdbcDialectImpl

mondrian.spi.impl.PostgreSqlDialect

mondrian.spi.impl.GreenplumDialect

All Implemented Interfaces:

Dialect

public class GreenplumDialect
extends PostgreSqlDialect

Implementation of Dialect for the GreenplumSQL database.

Since:

Dec 23, 2009

Author:

Millersoft

Nested Class Summary

Nested classes/interfaces inherited from interface mondrian.spi.Dialect

Dialect.DatabaseProduct, Dialect.Datatype

Field Summary

Fields

Modifier and Type	Field and Description
static JdbcDialectFactory	FACTORY

Fields inherited from class mondrian.spi.impl.JdbcDialectImpl

databaseProduct, permitsSelectNotInGroupBy, productVersion

Constructor Summary

Constructors

Constructor and Description
GreenplumDialect(Connection connection) Creates a GreenplumDialect.

Method Summary

Modifier and Type	Method and Description
boolean	allowsCountDistinct() Returns whether this Dialect supports distinct aggregations.
boolean	allowsRegularExpressionInWhereClause() Informs Mondrian if the dialect supports regular expressions when creating the 'where' or the 'having' clause.
String	generateCountExpression(String exp) Some databases, like Greenplum, don't include nulls as part of the results of a COUNT sql call.
Dialect.DatabaseProduct	getDatabaseProduct() Returns the database for this Dialect, or Dialect.DatabaseProduct.UNKNOWN if the database is not a common database.
boolean	requiresAliasForFromQuery() Returns whether this Dialect requires subqueries in the FROM clause to have an alias.
boolean	requiresGroupByAlias() Returns true if this Dialect can include expressions in the GROUP BY clause only by adding an expression to the SELECT clause and using its alias.
boolean	supportsGroupingSets() Returns whether this Dialect allows the GROUPING SETS construct in the GROUP BY clause.

Methods inherited from class mondrian.spi.impl.PostgreSqlDialect

generateOrderByNulls, generateRegularExpression, getType

Methods inherited from class mondrian.spi.impl.JdbcDialectImpl

allowsAs, allowsCompoundCountDistinct, allowsCountDistinctWithOtherAggs, allowsDdl, allowsDialectSharing, allowsFromQuery, allowsJoinOn, allowsMultipleCountDistinct, allowsMultipleDistinctSqlMeasures, allowsOrderByAlias, allowsSelectNotInGroupBy, appendHintsAfterFromClause, caseWhenElse, computeStatisticsProviders, deduceIdentifierQuoteString, deduceMaxColumnNameLength, deduceProductName, deduceProductVersion, deduceReadOnly, deduceSupportedResultSetStyles, deduceSupportsSelectNotInGroupBy, generateInline, generateInlineForAnsi, generateInlineGeneric, generateOrderByNullsAnsi, generateOrderItem, getMaxColumnNameLength, getProduct, getQuoteIdentifierString, getStatisticsProviders, isDatabase, needsExponent, quote, quoteBooleanLiteral, quoteDateLiteral, quoteDateLiteral, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteNumericLiteral, quoteStringLiteral, quoteTimeLiteral, quoteTimestampLiteral, requiresHavingAlias, requiresOrderByAlias, requiresUnionOrderByExprToBeInSelectClause, requiresUnionOrderByOrdinal, supportsGroupByExpressions, supportsMultiValueInExpr, supportsResultSetConcurrency, supportsUnlimitedValueList, toString, toUpper

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

FACTORY

public static final JdbcDialectFactory FACTORY

Constructor Detail

GreenplumDialect

public GreenplumDialect(Connection connection)
                 throws SQLException

Creates a GreenplumDialect.

Parameters:

connection - Connection

Throws:

SQLException

Method Detail

supportsGroupingSets

public boolean supportsGroupingSets()

Description copied from interface: Dialect

Returns whether this Dialect allows the GROUPING SETS construct in the GROUP BY clause. Currently Greenplum, IBM DB2, Oracle, and Teradata.

Specified by:

supportsGroupingSets in interface Dialect

Overrides:

supportsGroupingSets in class JdbcDialectImpl

Returns:

Whether this Dialect allows GROUPING SETS clause

requiresGroupByAlias

public boolean requiresGroupByAlias()

Description copied from interface: Dialect

Returns true if this Dialect can include expressions in the GROUP BY clause only by adding an expression to the SELECT clause and using its alias.

For example, in such a dialect,

SELECT x, x FROM t GROUP BY x

would be illegal, but

SELECT x AS a, x AS b FROM t ORDER BY a, b

would be legal.

Infobright is the only such dialect.

Specified by:

requiresGroupByAlias in interface Dialect

Overrides:

requiresGroupByAlias in class JdbcDialectImpl

Returns:

Whether this Dialect can include expressions in the GROUP BY clause only by adding an expression to the SELECT clause and using its alias

requiresAliasForFromQuery

public boolean requiresAliasForFromQuery()

Description copied from interface: Dialect

Returns whether this Dialect requires subqueries in the FROM clause to have an alias.

Specified by:

requiresAliasForFromQuery in interface Dialect

Overrides:

requiresAliasForFromQuery in class PostgreSqlDialect

Returns:

whether dialewct requires subqueries to have an alias

See Also:

Dialect.allowsFromQuery()

allowsCountDistinct

public boolean allowsCountDistinct()

Description copied from interface: Dialect

Returns whether this Dialect supports distinct aggregations.

For example, Access does not allow

select count(distinct x) from t

Specified by:

allowsCountDistinct in interface Dialect

Overrides:

allowsCountDistinct in class JdbcDialectImpl

Returns:

whether Dialect allows COUNT DISTINCT

getDatabaseProduct

public Dialect.DatabaseProduct getDatabaseProduct()

Description copied from interface: Dialect

Returns the database for this Dialect, or Dialect.DatabaseProduct.UNKNOWN if the database is not a common database.

Specified by:

getDatabaseProduct in interface Dialect

Overrides:

getDatabaseProduct in class PostgreSqlDialect

Returns:

Database

generateCountExpression

public String generateCountExpression(String exp)

Description copied from interface: Dialect

Some databases, like Greenplum, don't include nulls as part of the results of a COUNT sql call. This allows dialects to wrap the count expression in something before it is used in the query.

Specified by:

generateCountExpression in interface Dialect

Overrides:

generateCountExpression in class JdbcDialectImpl

Parameters:

exp - The expression to wrap.

Returns:

A valid expression to use for a count operation.

allowsRegularExpressionInWhereClause

public boolean allowsRegularExpressionInWhereClause()

Description copied from interface: Dialect

Informs Mondrian if the dialect supports regular expressions when creating the 'where' or the 'having' clause.

Specified by:

allowsRegularExpressionInWhereClause in interface Dialect

Overrides:

allowsRegularExpressionInWhereClause in class PostgreSqlDialect

Returns:

True if regular expressions are supported.