mondrian.spi.impl

Class MonetDbDialect

java.lang.Object

mondrian.spi.impl.JdbcDialectImpl

mondrian.spi.impl.MonetDbDialect

All Implemented Interfaces:

Dialect

public class MonetDbDialect
extends JdbcDialectImpl

Implementation of Dialect for the MonetDB database.

Since:

Nov 10, 2012

Author:

pstoellberger

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
MonetDbDialect()
MonetDbDialect(Connection connection) Creates a MonetDbDialect.

Method Summary

Modifier and Type	Method and Description
boolean	allowsCompoundCountDistinct() Returns whether this Dialect allows multiple arguments to the COUNT(DISTINCT ...) aggregate function, for example SELECT COUNT(DISTINCT x, y) FROM t
boolean	allowsCountDistinct() Returns whether this Dialect supports distinct aggregations.
boolean	allowsCountDistinctWithOtherAggs() Returns whether this Dialect supports distinct aggregations with other aggregations in the same query.
boolean	allowsMultipleCountDistinct() Returns whether this Dialect supports more than one distinct aggregation in the same query.
boolean	allowsMultipleDistinctSqlMeasures() Returns whether this Dialect has performant support of distinct SQL measures in the same query.
int	compareVersions(String v1, String v2) Compares two MonetDB versions that contain only digits separated by dots.
SqlStatement.Type	getType(ResultSetMetaData metaData, int columnIndex) Chooses the most appropriate type for accessing the values of a column in a result set for a dialect.
void	quoteStringLiteral(StringBuilder buf, String s) Appends to a buffer a single-quoted SQL string.
boolean	requiresAliasForFromQuery() Returns whether this Dialect requires subqueries in the FROM clause to have an alias.
boolean	supportsGroupByExpressions() Returns whether this Dialect supports expressions in the GROUP BY clause.

Methods inherited from class mondrian.spi.impl.JdbcDialectImpl

allowsAs, allowsDdl, allowsDialectSharing, allowsFromQuery, allowsJoinOn, allowsOrderByAlias, allowsRegularExpressionInWhereClause, allowsSelectNotInGroupBy, appendHintsAfterFromClause, caseWhenElse, computeStatisticsProviders, deduceIdentifierQuoteString, deduceMaxColumnNameLength, deduceProductName, deduceProductVersion, deduceReadOnly, deduceSupportedResultSetStyles, deduceSupportsSelectNotInGroupBy, extractEmbeddedFlags, generateCountExpression, generateInline, generateInlineForAnsi, generateInlineGeneric, generateOrderByNulls, generateOrderByNullsAnsi, generateOrderItem, generateRegularExpression, getDatabaseProduct, getMaxColumnNameLength, getProduct, getQuoteIdentifierString, getStatisticsProviders, isDatabase, needsExponent, quote, quoteBooleanLiteral, quoteDateLiteral, quoteDateLiteral, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteNumericLiteral, quoteTimeLiteral, quoteTimestampLiteral, quoteTimestampLiteral, requiresGroupByAlias, requiresHavingAlias, requiresOrderByAlias, requiresUnionOrderByExprToBeInSelectClause, requiresUnionOrderByOrdinal, supportsGroupingSets, 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

MonetDbDialect

public MonetDbDialect(Connection connection)
               throws SQLException

Creates a MonetDbDialect.

Parameters:

connection - Connection

Throws:

SQLException - on error

MonetDbDialect

public MonetDbDialect()

Method Detail

allowsMultipleDistinctSqlMeasures

public boolean allowsMultipleDistinctSqlMeasures()

Description copied from interface: Dialect

Returns whether this Dialect has performant support of distinct SQL measures in the same query.

Specified by:

allowsMultipleDistinctSqlMeasures in interface Dialect

Overrides:

allowsMultipleDistinctSqlMeasures in class JdbcDialectImpl

Returns:

whether this dialect supports multiple count(distinct subquery) measures in one query.

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

allowsCountDistinctWithOtherAggs

public boolean allowsCountDistinctWithOtherAggs()

Description copied from interface: Dialect

Returns whether this Dialect supports distinct aggregations with other aggregations in the same query. This may be enabled for performance reasons (Vertica)

Specified by:

allowsCountDistinctWithOtherAggs in interface Dialect

Overrides:

allowsCountDistinctWithOtherAggs in class JdbcDialectImpl

Returns:

whether this Dialect supports more than one distinct aggregation in the same query

allowsMultipleCountDistinct

public boolean allowsMultipleCountDistinct()

Description copied from interface: Dialect

Returns whether this Dialect supports more than one distinct aggregation in the same query.

In Derby 10.1,

select couunt(distinct x) from t

is OK, but

select couunt(distinct x), count(distinct y) from t

gives "Multiple DISTINCT aggregates are not supported at this time."

Specified by:

allowsMultipleCountDistinct in interface Dialect

Overrides:

allowsMultipleCountDistinct in class JdbcDialectImpl

Returns:

whether this Dialect supports more than one distinct aggregation in the same query

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 JdbcDialectImpl

Returns:

whether dialewct requires subqueries to have an alias

See Also:

Dialect.allowsFromQuery()

allowsCompoundCountDistinct

public boolean allowsCompoundCountDistinct()

Description copied from interface: Dialect

Returns whether this Dialect allows multiple arguments to the COUNT(DISTINCT ...) aggregate function, for example

SELECT COUNT(DISTINCT x, y) FROM t

Specified by:

allowsCompoundCountDistinct in interface Dialect

Overrides:

allowsCompoundCountDistinct in class JdbcDialectImpl

Returns:

whether Dialect allows multiple arguments to COUNT DISTINCT

See Also:

Dialect.allowsCountDistinct(), Dialect.allowsMultipleCountDistinct()

supportsGroupByExpressions

public boolean supportsGroupByExpressions()

Description copied from interface: Dialect

Returns whether this Dialect supports expressions in the GROUP BY clause. Derby/Cloudscape and Infobright do not.

Specified by:

supportsGroupByExpressions in interface Dialect

Overrides:

supportsGroupByExpressions in class JdbcDialectImpl

Returns:

Whether this Dialect allows expressions in the GROUP BY clause

quoteStringLiteral

public void quoteStringLiteral(StringBuilder buf,
                               String s)

Description copied from interface: Dialect

Appends to a buffer a single-quoted SQL string.

For example, in the default dialect, quoteStringLiteral(buf, "Can't") appends "'Can''t'" to buf.

Specified by:

quoteStringLiteral in interface Dialect

Overrides:

quoteStringLiteral in class JdbcDialectImpl

Parameters:

buf - Buffer to append to

s - Literal

getType

public SqlStatement.Type getType(ResultSetMetaData metaData,
                                 int columnIndex)
                          throws SQLException

Description copied from interface: Dialect

Chooses the most appropriate type for accessing the values of a column in a result set for a dialect.

Dialect-specific nuances involving type representation should be encapsulated in implementing methods. For example, if a dialect has implicit rules involving scale or precision, they should be handled within this method so the client can simply retrieve the "best fit" SqlStatement.Type for the column.

Specified by:

getType in interface Dialect

Overrides:

getType in class JdbcDialectImpl

Parameters:

metaData - Results set metadata

columnIndex - Column ordinal (0-based)

Returns:

the most appropriate SqlStatement.Type for the column

Throws:

SQLException

compareVersions

public int compareVersions(String v1,
                           String v2)

Compares two MonetDB versions that contain only digits separated by dots.

Examples of MonetDB versions:

11.17.17

11.5.3

Parameters:

v1 - the first version be compared

v2 - the second version to be compared

Returns:

the value 0 if two versions are equal; a value less than 0 if the first version number is less than the second one; and a value greater than 0 if the first version number is greater than the second one.