Alter fragment on index is slow
Hi,
RHEL 6.4 64 bits
IDS 12.10.FC4
I have a table (aprox. 1000 millions of records) fragmented by expression
(table and indexes). This table has three indexes. One of the index is:
create index "dwh".ind1_facturacionx on "dwh".facturacion (dia_proceso,
clave_documento) using btree
fragment by expression
(dia_proceso <= 10195 ) in dwh2qdbs,
((dia_proceso > 10195 ) AND (dia_proceso <= 10653 ) ) in
dwh2rdbs,
((dia_proceso > 10653 ) AND (dia_proceso <= 11346 ) ) in
dwh3rfi,
((dia_proceso > 11346 ) AND (dia_proceso <= 11761 ) ) in
dwh5rfi,
((dia_proceso > 11761 ) AND (dia_proceso <= 12161 ) ) in
dwh6rfi,
((dia_proceso > 12161 ) AND (dia_proceso <= 12915 ) ) in
dwh7rfi,
((dia_proceso > 12915 ) AND (dia_proceso <= 13380 ) ) in
dwh8rfi;
The field dia_proceso is a smallint and clave_documento is char(2).
Notice this part of the definition:
((dia_proceso > 12915 ) AND (dia_proceso <= 13380 ) ) in dwh8rfi;
I've run this sentence:
ALTER FRAGMENT ON INDEX ind1_facturacionxMODIFY dwh8rfi to dia_proceso > 12915 IN dwh8rfi;
I tooks aprox. 79 minutes.
My question is:
Why this alter fragment take a long time ? There is no data movement and I
think the data validation is not necessary.
Regards.
Roger