In memory area is enough ,but table can't POPULATED in memory ,cause query in memory slower

Question

hI
any expert can take a look this issue, thanks
SQL>  select *　FROM　gv$inmemory_area order by 1;
   INST_ID POOL ALLOC_BYTES USED_BYTES POPULATE_STATUS CON_ID
1 64KB POOL 4278190080   17301504 DONE 0
1 1MB POOL 17177772032 9377415168 DONE 0
2 1MB POOL 17177772032 9380560896 DONE 0
2 64KB POOL 4278190080   17301504 DONE 0
3 64KB POOL 4278190080   17301504 DONE 0
3 1MB POOL 17177772032 9385803776 DONE 0
4 1MB POOL 17177772032 9546235904 DONE 0
4 64KB POOL 4278190080   17301504 DONE                                0
8 rows selected
(IN MEMORY AREA SIZE IS BIG enough)
SQL> SELECT v.owner, v.segment_name name,v.populate_status status, v.bytes_not_populated FROM  v$im_segments v;
OWNER                                                                            NAME                                                                             STATUS    BYTES_NOT_POPULATED
BI                                                                               PERFTABLE5                                                                       COMPLETED                   0
BI                                                                               PERFTABLE3                                                                       COMPLETED                   0
BI                                                                               PERFTABLE4                                                                       COMPLETED                   0
BI                                                                               PERFTABLE2                                                                       COMPLETED                   0
BI                                                                               PERFTABLE3                                                                       COMPLETED                   0
BI                                                                               PERFTABLE1                                                                       COMPLETED           165855232
BI                                                                               PERFTABLE4                                                                       COMPLETED                   0
BI                                                                               PERFTABLE3                                                                       COMPLETED                   0
BI                                                                               PERFTABLE1                                                                       COMPLETED                   0
BI                                                                               PERFTABLE4                                                                       COMPLETED                   0
BI                                                                               PERFTABLE5                                                                       COMPLETED                   0
BI                                                                               PERFTABLE3                                                                       COMPLETED                   0
BI                                                                               PERFTABLE2                                                                       COMPLETED                   0
BI                                                                               PERFTABLE1                                                                       COMPLETED           165855232
(table  PERFTABLE1   have NOT_POPULATED data) .
cause :IO Requests
select count(*) from perftable1 a, perftable1 b where a.int32_f1 = b.int32_f1.
SQL Plan Monitoring Details (Plan Hash Value=1965173750)
Id
Operation
Name
Estimated
Rows
Cost
Active Period
(100s)
Execs
Rows
Memory
Temp
IO Requests
CPU Activity
Wait Activity
Progress
SELECT STATEMENT
1
. SORT AGGREGATE
1
1
.. PX COORDINATOR
49
... PX SEND QC (RANDOM)
:TQ10000
1
48
.... SORT AGGREGATE
1
48
..... PX PARTITION HASH ALL
202M
81245
48
->
...... HASH JOIN
202M
81245
48
0
689.9MB
1.0GB
3031 (10%)
32%
8.2%
->
....... TABLE ACCESS INMEMORY FULL
PERFTABLE1
200M
36854
48
77M
29926 (105%)
67%
91%
473s
....... TABLE ACCESS INMEMORY FULL
PERFTABLE1
200M
36854

Answer 1

This is the wrong forum for this question. This forum is for the TimesTen In-Memory Database while your question is about the Oracle Database 12c In-Memory Option. Best post this in the main Oracle Database forum.
Chris