Oracle XMLAGG performance
Table T1 has ~100 million rows. Unique key ( Key1, Key2, Key3 ) count is around 3 million. I am aggregating field1 as a comma separated value grouped on Key1, Key2, Key3. Tried LISTAGG, but due to 4000 byte limitation started using XMLAGG with getClobVal() to get the value as a CLOB and writing into a table. Its been running for more than 90 minutes. Temp space usage is roughly around 10% at the moment. Is there a better way of doing this to speed up the performance ? Any input is welcome.
CREATE TABLE T1_AGGR
AS
Select /*+ PARALLEL */
Key1, Key2, Key3,
rtrim(
xmlagg(
xmlelement( e, field1 || ',' )
).extract( '//text()').getClobVal(), ',' ) dataValue
FROM T1
GROUP BY Key1, Key2, Key3;
oracle aggregate database-performance clob
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
add a comment |
Table T1 has ~100 million rows. Unique key ( Key1, Key2, Key3 ) count is around 3 million. I am aggregating field1 as a comma separated value grouped on Key1, Key2, Key3. Tried LISTAGG, but due to 4000 byte limitation started using XMLAGG with getClobVal() to get the value as a CLOB and writing into a table. Its been running for more than 90 minutes. Temp space usage is roughly around 10% at the moment. Is there a better way of doing this to speed up the performance ? Any input is welcome.
CREATE TABLE T1_AGGR
AS
Select /*+ PARALLEL */
Key1, Key2, Key3,
rtrim(
xmlagg(
xmlelement( e, field1 || ',' )
).extract( '//text()').getClobVal(), ',' ) dataValue
FROM T1
GROUP BY Key1, Key2, Key3;
oracle aggregate database-performance clob
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
See oracle-base.com/articles/misc/string-aggregation-techniques
– Kaushik Nayak
Nov 16 '18 at 4:31
add a comment |
Table T1 has ~100 million rows. Unique key ( Key1, Key2, Key3 ) count is around 3 million. I am aggregating field1 as a comma separated value grouped on Key1, Key2, Key3. Tried LISTAGG, but due to 4000 byte limitation started using XMLAGG with getClobVal() to get the value as a CLOB and writing into a table. Its been running for more than 90 minutes. Temp space usage is roughly around 10% at the moment. Is there a better way of doing this to speed up the performance ? Any input is welcome.
CREATE TABLE T1_AGGR
AS
Select /*+ PARALLEL */
Key1, Key2, Key3,
rtrim(
xmlagg(
xmlelement( e, field1 || ',' )
).extract( '//text()').getClobVal(), ',' ) dataValue
FROM T1
GROUP BY Key1, Key2, Key3;
oracle aggregate database-performance clob
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
Table T1 has ~100 million rows. Unique key ( Key1, Key2, Key3 ) count is around 3 million. I am aggregating field1 as a comma separated value grouped on Key1, Key2, Key3. Tried LISTAGG, but due to 4000 byte limitation started using XMLAGG with getClobVal() to get the value as a CLOB and writing into a table. Its been running for more than 90 minutes. Temp space usage is roughly around 10% at the moment. Is there a better way of doing this to speed up the performance ? Any input is welcome.
CREATE TABLE T1_AGGR
AS
Select /*+ PARALLEL */
Key1, Key2, Key3,
rtrim(
xmlagg(
xmlelement( e, field1 || ',' )
).extract( '//text()').getClobVal(), ',' ) dataValue
FROM T1
GROUP BY Key1, Key2, Key3;
oracle aggregate database-performance clob
oracle aggregate database-performance clob
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
asked Nov 16 '18 at 3:53
dpsahoodpsahoo
125
125
See oracle-base.com/articles/misc/string-aggregation-techniques
– Kaushik Nayak
Nov 16 '18 at 4:31
add a comment |
See oracle-base.com/articles/misc/string-aggregation-techniques
– Kaushik Nayak
Nov 16 '18 at 4:31
See oracle-base.com/articles/misc/string-aggregation-techniques
– Kaushik Nayak
Nov 16 '18 at 4:31
See oracle-base.com/articles/misc/string-aggregation-techniques
– Kaushik Nayak
Nov 16 '18 at 4:31
add a comment |
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See oracle-base.com/articles/misc/string-aggregation-techniques
– Kaushik Nayak
Nov 16 '18 at 4:31