Package 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

  • Field Details

  • Constructor Details

    • MonetDbDialect

      public MonetDbDialect(Connection connection) throws SQLException
      Creates a MonetDbDialect.
      Parameters:
      connection - Connection
      Throws:
      SQLException - on error

    • MonetDbDialect

      public MonetDbDialect()

  • Method Details

    • 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:

    • 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:

    • 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.