]
Steven Hawkins resolved TEIID-3957.
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Resolution: Done
Added support for pushdown - if no order by is specified, then we'll add a dummy order
by 1.
Impala translator - Add pushdown of offset in LIMIT clause to
overcome difference in LIMIT clause
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Key: TEIID-3957
URL:
https://issues.jboss.org/browse/TEIID-3957
Project: Teiid
Issue Type: Enhancement
Components: JDBC Connector
Affects Versions: 8.12.4
Environment: Ubuntu Trusty
Reporter: Don Krapohl
Assignee: Steven Hawkins
Priority: Minor
Fix For: 9.0
With the impala translator we issue this LIMIT to Teiid:
ORDER BY somecolumn DESC LIMIT 75, 25
this means give me 25 rows starting from *ROW* 76.
In Impala's SQL this should be translated to:
ORDER BY somecolumn DESC LIMIT 25 OFFSET 75
BUT this means give me 25 rows starting from *PAGE * 76 (with page size of 25 rows)
ref:
http://www.cloudera.com/documentation/archive/impala/2-x/2-1-x/topics/imp...
The Teiid Impala translator doesn't push the offset but sums the limit and offset:
ORDER BY somecolumn DESC LIMIT 100
Request we add pushdown, which will be more efficient and overcome the difference in how
offsets are handled between Impala and Teiid.