Module jakarta.json

Package com.exasol.adapter.dialects.exasol

Class ExasolLocalQueryRewriter

java.lang.Object

com.exasol.adapter.dialects.exasol.ExasolLocalQueryRewriter

All Implemented Interfaces:

com.exasol.adapter.dialects.QueryRewriter

public class ExasolLocalQueryRewriter
extends Object
implements com.exasol.adapter.dialects.QueryRewriter

Exasol-specific query rewriter for cases where the IS_LOCAL option is used.

In this case the query is rewritten into a SELECT rather than to the usual IMPORT statement. This way the Virtual Schema query can directly be executed on the local database in the context of the statement it was embedded in. That saves the overhead of using the ExaLoader and is thus considerably faster.

Constructor Summary

Constructors

Constructor	Description
ExasolLocalQueryRewriter(com.exasol.adapter.dialects.SqlDialect dialect)	Create a new instance of the ExasolLocalQueryRewriter.

Method Summary

Modifier and Type	Method	Description
String	rewrite(com.exasol.adapter.sql.SqlStatement statement, List<com.exasol.adapter.metadata.DataType> selectListDataTypes, com.exasol.ExaMetadata exaMetadata, com.exasol.adapter.AdapterProperties properties)

Methods inherited from class java.lang.Object

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

Constructor Detail

ExasolLocalQueryRewriter

public ExasolLocalQueryRewriter(com.exasol.adapter.dialects.SqlDialect dialect)

Create a new instance of the ExasolLocalQueryRewriter.

Parameters:

dialect - dialect

Method Detail

rewrite

public String rewrite(com.exasol.adapter.sql.SqlStatement statement,
                      List<com.exasol.adapter.metadata.DataType> selectListDataTypes,
                      com.exasol.ExaMetadata exaMetadata,
                      com.exasol.adapter.AdapterProperties properties)
               throws com.exasol.adapter.AdapterException

Specified by:

rewrite in interface com.exasol.adapter.dialects.QueryRewriter

Throws:

com.exasol.adapter.AdapterException