Results of multiple select statements in IMPORT truncated

Detail name	Value
Changelog Number	7036
Type	Bug
Status	Resolved
Affected Versions	Exasol 6.1.0, EXASOL 6.0.9
Fix Versions	Exasol 6.0.14, Exasol 6.1.2
Resolution Date	2019-02-01

Background

Starting with Exasol 6.0.9, IMPORT from oracle supports multiple remote statements for parallelism (see EXASOL-2272)

Problem

When executing such an import and data types do not match across all statements, the imported string data may get truncated without error/warning.

Example:

import into t32 from ORA at EXADATA_ORA
 STATEMENT 'SELECT ''P0'' AS "PARTI" FROM DUAL'
 STATEMENT 'SELECT ''P10'' AS "PARTI" FROM DUAL';

The resulting string data may get truncated:

PARTI
P0
P1

when the expected correct result would have been:

PARTI
P0
P10

Workaround:

A workaround is to re-order the statements such that the statement with largest result row comes first:

import into t32 from ORA at EXADATA_ORA
 STATEMENT 'SELECT' 'P10' 'AS "PARTI" FROM "MY_SCHEMA" "MY_TABLE" PARTITION ("P10")'
 STATEMENT 'SELECT' 'P0' 'AS "PARTI" FROM "MY_SCHEMA". "MY_TABLE" PARTITION ("P0")'
;

in this case, the result row set is not truncated (remember: order of result set is not assured)