Package com.amazonaws.athena.connectors.teradata

Class TeradataSqlDialect

java.lang.Object

org.apache.calcite.sql.SqlDialect

org.apache.calcite.sql.dialect.TeradataSqlDialect

com.amazonaws.athena.connectors.teradata.TeradataSqlDialect

public class TeradataSqlDialect
extends org.apache.calcite.sql.dialect.TeradataSqlDialect

Custom SQL dialect for Teradata that extends Calcite's TeradataSqlDialect to handle Teradata-specific SQL generation for Athena query federation.

This dialect overrides the default OFFSET/FETCH unparsing behavior because Teradata does not support standard SQL LIMIT, OFFSET, or FETCH NEXT clauses. Athena's query federation framework uses Calcite to generate SQL pushed down to the source database, and without this override, Calcite would emit OFFSET/FETCH syntax that Teradata cannot execute.

See Also:

TeradataQueryStringBuilder.getSqlDialect(), TeradataQueryStringBuilder.appendLimitOffset(com.amazonaws.athena.connector.lambda.domain.Split, com.amazonaws.athena.connector.lambda.domain.predicate.Constraints)

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.calcite.sql.SqlDialect

org.apache.calcite.sql.SqlDialect.CalendarPolicy, org.apache.calcite.sql.SqlDialect.Context, org.apache.calcite.sql.SqlDialect.DatabaseProduct, org.apache.calcite.sql.SqlDialect.FakeUtil

Field Summary

Fields inherited from class org.apache.calcite.sql.dialect.TeradataSqlDialect

DEFAULT, DEFAULT_CONTEXT

Fields inherited from class org.apache.calcite.sql.SqlDialect

BUILT_IN_OPERATORS_LIST, EMPTY_CONTEXT, identifierEndQuoteString, identifierEscapedQuote, identifierQuoteString, literalEndQuoteString, literalEscapedQuote, literalQuoteString, LOGGER, nullCollation

Constructor Summary

Constructors

Constructor	Description
TeradataSqlDialect()	Constructs a new TeradataSqlDialect using the TeradataSqlDialect.DEFAULT_CONTEXT from Calcite's built-in Teradata dialect.

Method Summary

Modifier and Type	Method	Description
void	unparseOffsetFetch(org.apache.calcite.sql.SqlWriter writer, @Nullable org.apache.calcite.sql.SqlNode offset, @Nullable org.apache.calcite.sql.SqlNode fetch)	No-op override that suppresses OFFSET/FETCH clause generation.

Methods inherited from class org.apache.calcite.sql.SqlDialect

allowsAs, configureParser, configureParser, containsNonAscii, create, defaultNullDirection, emulateJoinTypeForCrossJoin, emulateNullDirection, emulateNullDirectionWithIsNull, getCalendarPolicy, getCastSpec, getConformance, getDatabaseProduct, getFormatModel, getNullCollation, getProduct, getQuotedCasing, getQuoting, getSingleRowTableName, getTypeSystem, getUnquotedCasing, hasImplicitTableAlias, identifierNeedsQuote, isCaseSensitive, prepareUnparse, quoteIdentifier, quoteIdentifier, quoteIdentifier, quoteStringLiteral, quoteStringLiteral, quoteStringLiteralUnicode, quoteTimestampLiteral, requiresAliasForFromItems, rewriteMaxMin, rewriteMaxMinExpr, rewriteSingleValueExpr, supportBooleanCaseWhen, supportsAggregateFunction, supportsAggregateFunctionFilter, supportsAliasedValues, supportsApproxCountDistinct, supportsCharSet, supportsDataType, supportsFunction, supportsGroupByLiteral, supportsGroupByWithCube, supportsGroupByWithRollup, supportsImplicitTypeCoercion, supportsJoinType, supportsNestedAggregations, supportsOffsetFetch, supportsTimestampPrecision, supportsWindowFunctions, unparseBoolLiteral, unparseCall, unparseDateTimeLiteral, unparseFetchUsingAnsi, unparseFetchUsingLimit, unparseLimit, unparseNumericLiteral, unparseOffset, unparseSqlDatetimeArithmetic, unparseSqlIntervalLiteral, unparseSqlIntervalQualifier, unparseSqlSetOption, unparseTableScanHints, unparseTopN, unquoteStringLiteral

Methods inherited from class java.lang.Object

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

Constructor Detail

TeradataSqlDialect

public TeradataSqlDialect()

Constructs a new TeradataSqlDialect using the TeradataSqlDialect.DEFAULT_CONTEXT from Calcite's built-in Teradata dialect.

Method Detail

unparseOffsetFetch

public void unparseOffsetFetch(org.apache.calcite.sql.SqlWriter writer,
                               @Nullable org.apache.calcite.sql.SqlNode offset,
                               @Nullable org.apache.calcite.sql.SqlNode fetch)

No-op override that suppresses OFFSET/FETCH clause generation.

Teradata does not support the standard SQL OFFSET/FETCH NEXT syntax. This method intentionally writes nothing to the SqlWriter, preventing Calcite from emitting unsupported clauses in the pushed-down query.

Overrides:

unparseOffsetFetch in class org.apache.calcite.sql.SqlDialect

Parameters:

writer - the SQL writer building the output query

offset - the OFFSET node (ignored)

fetch - the FETCH node (ignored)