Oracle trunc affects Efficiency

Oracle trunc does not perform function processing on the time field, which is very slow and Low-each time a record is extracted, a function must be performed on the time field to determine whether select count (1) is appropriate) FROM A_BASIC_CS_RADIO_H where trunc (COLLECTTIME) = TRUNC (SYSDATE)-1 generally takes 4-5 seconds. Efficient -- you can directly determine whether select count (1) FROM A_BASIC_CS_RADIO_H WHERECOLLECTTIME> = trunc (sysdate-1) and collecttime <trunc (sysdate) generally takes 0.05 seconds.