I am trying to find the technical reason for why Oracle cannot use parallel
slaves to build a single-column index on a sparse column with few distinct
Just by playing around, I discovered that if I put this column as the
leading edge on an index with many columns, it can be built in parallel.
According to the relevant documentation
I would expect that the base table is sampled, but perhaps the random
sampling returns 0 keys due to the sparse nature of the column?
Oracle Enterprise Edition 18.104.22.168
table is partitioned, but not on this key (lol)
ddl extracted via datapump:
CREATE INDEX "FIMSMGR"."FGBTRND_ENCD_INDEX" ON "FIMSMGR"."FGBTRND"
PCTFREE 10 INITRANS 2 MAXTRANS 255
STORAGE(INITIAL 5242880 NEXT 5242880 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "FIN_LARGE_INDX" PARALLEL 100 ;