4. The method of claim 3 , further comprising: repeating the determining, the selecting, and the generating for each unique term occurring in the one or more records of the log streams corresponding to the interval, wherein the generating the estimate for the number of occurrences of the logical combination of terms in the defined interval of records for each of the logical combinations of terms in the set uses the information of the one of a bit-array data structure, a min-wise independent permutation locality sensitive hashing (MinHash) data structure, and a histogram data structure characterizing occurrences of each unique term among the terms in the logical combination of terms defined by the search query.
8. The method of claim 4 , further comprising: identifying records having corresponding intervals that overlap the defined interval from the search query; and for each of the logical combination of terms in the set defined by the search query, generating the estimate for the number of occurrences of the logical combination of terms in the records having corresponding intervals that overlap the defined interval from the search query.