A total of 1 million records of the MOT_C_DATA table is 650M
Among them, there is Bitmap Index on Activity? It has two values 0? And 1 ?? 1 is about 10,000
Now I want
Select * from mot_c_data where activity = '1';
Expain Plan
Do not use index ?? and bytes is 150M
Then I am in force INDEX
SELECT / * INDEX (MOT_C_DATA) * / * from Mot_c_data where activty = '1';
But it is not seen, and Bytes is still 150m.
All I use CTAS to reorganize this table
Create Table Mot_c_data_bak assect from mot_c_data order by activity;
Drop Table Mot_c_data;
ALTER TABLE MOT_C_DATA_BAK RENAME To MOT_C_DATA;
then
Select * from mot_c_data where activity = '1';
Many Bytes is only 20m;
