Package mondrian.spi.impl

Class VerticaDialect

java.lang.Object

mondrian.spi.impl.JdbcDialectImpl

mondrian.spi.impl.VerticaDialect

All Implemented Interfaces:

Dialect

public class VerticaDialect
extends JdbcDialectImpl

Implementation of Dialect for the Vertica database.

Since:

Sept 11, 2009

Author:

Pedro Alves

Nested Class Summary

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

Dialect.DatabaseProduct, Dialect.Datatype

Field Summary

Fields

Modifier and Type	Field	Description
static final JdbcDialectFactory	FACTORY

Fields inherited from class mondrian.spi.impl.JdbcDialectImpl

databaseProduct, permitsSelectNotInGroupBy, productVersion

Constructor Summary

Constructors

Constructor	Description
VerticaDialect(Connection connection)	Creates a VerticaDialect.

Method Summary

Modifier and Type	Method	Description
boolean	allowsCountDistinctWithOtherAggs()	Returns whether this Dialect supports distinct aggregations with other aggregations in the same query.
boolean	allowsFromQuery()	Returns whether this Dialect allows a subquery in the from clause, for example SELECT * FROM (SELECT * FROM t) AS x
boolean	allowsMultipleCountDistinct()	Returns whether this Dialect supports more than one distinct aggregation in the same query.
boolean	allowsRegularExpressionInWhereClause()	Informs Mondrian if the dialect supports regular expressions when creating the 'where' or the 'having' clause.
String	generateInline(List<String> columnNames, List<String> columnTypes, List<String[]> valueList)	Generates a SQL statement to represent an inline dataset.
String	generateRegularExpression(String source, String javaRegex)	Must generate a String representing a regular expression match operation between a string literal and a Java regular expression.
Dialect.DatabaseProduct	getDatabaseProduct()	Returns the database for this Dialect, or Dialect.DatabaseProduct.UNKNOWN if the database is not a common database.
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.
boolean	requiresAliasForFromQuery()	Returns whether this Dialect requires subqueries in the FROM clause to have an alias.
boolean	supportsMultiValueInExpr()	Returns true if this dialect supports multi-value IN expressions.
boolean	supportsResultSetConcurrency(int type, int concurrency)	Returns whether this Dialect supports the given concurrency type in combination with the given result set type.

Methods inherited from class mondrian.spi.impl.JdbcDialectImpl

allowsAs, allowsCompoundCountDistinct, allowsCountDistinct, allowsDdl, allowsDialectSharing, allowsJoinOn, allowsMultipleDistinctSqlMeasures, allowsOrderByAlias, allowsSelectNotInGroupBy, appendHintsAfterFromClause, caseWhenElse, computeStatisticsProviders, deduceIdentifierQuoteString, deduceMaxColumnNameLength, deduceProductName, deduceProductVersion, deduceReadOnly, deduceSupportedResultSetStyles, deduceSupportsSelectNotInGroupBy, extractEmbeddedFlags, generateCountExpression, generateInlineForAnsi, generateInlineGeneric, generateOrderByNulls, generateOrderByNullsAnsi, generateOrderItem, getMaxColumnNameLength, getProduct, getQuoteIdentifierString, getStatisticsProviders, isDatabase, needsExponent, quote, quoteBooleanLiteral, quoteDateLiteral, quoteDateLiteral, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteNumericLiteral, quoteStringLiteral, quoteTimeLiteral, quoteTimestampLiteral, quoteTimestampLiteral, requiresGroupByAlias, requiresHavingAlias, requiresOrderByAlias, requiresUnionOrderByExprToBeInSelectClause, requiresUnionOrderByOrdinal, supportsGroupByExpressions, supportsGroupingSets, supportsUnlimitedValueList, toString, toUpper

Methods inherited from class java.lang.Object

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

Field Details

FACTORY

public static final JdbcDialectFactory FACTORY

Constructor Details

VerticaDialect

public VerticaDialect(Connection connection)
               throws SQLException

Creates a VerticaDialect.

Parameters:

connection - Connection

Throws:

SQLException

Method Details

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()

allowsFromQuery

public boolean allowsFromQuery()

Description copied from interface: Dialect

Returns whether this Dialect allows a subquery in the from clause, for example

SELECT * FROM (SELECT * FROM t) AS x

Specified by:

allowsFromQuery in interface Dialect

Overrides:

allowsFromQuery in class JdbcDialectImpl

Returns:

whether Dialect allows subquery in FROM clause

See Also:

• Dialect.requiresAliasForFromQuery()

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 JdbcDialectImpl

Returns:

Database

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

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

supportsResultSetConcurrency

public boolean supportsResultSetConcurrency(int type,
 int concurrency)

Description copied from interface: Dialect

Returns whether this Dialect supports the given concurrency type in combination with the given result set type.

The result is similar to DatabaseMetaData.supportsResultSetConcurrency(int, int), except that the JdbcOdbc bridge in JDK 1.6 overstates its abilities. See bug 1690406.

Specified by:

supportsResultSetConcurrency in interface Dialect

Overrides:

supportsResultSetConcurrency in class JdbcDialectImpl

Parameters:

type - defined in ResultSet

concurrency - type defined in ResultSet

Returns:

true if so; false otherwise

generateInline

public String generateInline(List<String> columnNames,
 List<String> columnTypes,
 List<String[]> valueList)

Description copied from interface: Dialect

Generates a SQL statement to represent an inline dataset.

For example, for Oracle, generates

 SELECT 1 AS FOO, 'a' AS BAR FROM dual
 UNION ALL
 SELECT 2 AS FOO, 'b' AS BAR FROM dual
 

For ANSI SQL, generates:

 VALUES (1, 'a'), (2, 'b')
 

Specified by:

generateInline in interface Dialect

Overrides:

generateInline in class JdbcDialectImpl

Parameters:

columnNames - List of column names

columnTypes - List of column types ("String" or "Numeric")

valueList - List of rows values

Returns:

SQL string

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

supportsMultiValueInExpr

public boolean supportsMultiValueInExpr()

Description copied from interface: Dialect

Returns true if this dialect supports multi-value IN expressions. E.g., WHERE (col1, col2) IN ((val1a, val2a), (val1b, val2b))

Specified by:

supportsMultiValueInExpr in interface Dialect

Overrides:

supportsMultiValueInExpr in class JdbcDialectImpl

Returns:

true if the dialect supports multi-value IN expressions

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 JdbcDialectImpl

Returns:

True if regular expressions are supported.

generateRegularExpression

public String generateRegularExpression(String source,
 String javaRegex)

Description copied from interface: Dialect

Must generate a String representing a regular expression match operation between a string literal and a Java regular expression. The string literal might be a column identifier or some other identifier, but the implementation must presume that it is already escaped and fit for use. The regular expression is not escaped and must be adapted to the proper dialect rules.

Postgres / Greenplum example:

generateRegularExpression( "'foodmart'.'customer_name'", "(?i).*oo.*") -> 'foodmart'.'customer_name' ~ "(?i).*oo.*"

Oracle example:

generateRegularExpression( "'foodmart'.'customer_name'", ".*oo.*") -> REGEXP_LIKE('foodmart'.'customer_name', ".*oo.*")

Dialects are allowed to return null if the dialect cannot convert that particular regular expression into something that the database would support.

Specified by:

generateRegularExpression in interface Dialect

Overrides:

generateRegularExpression in class JdbcDialectImpl

Parameters:

source - A String identifying the column to match against.

javaRegex - A Java regular expression to match against.

Returns:

A dialect specific matching operation, or null if the dialect cannot convert that particular regular expression into something that the database would support.