Implementing a Bloom filter index as a hierarchical data structure. Bloom filters are received and their bit vectors are decomposed into successive bit sequences. For each bit sequence except the last one, memory for at least storing a pointer to a memory location on the next level is allocated on the level corresponding to the bit sequence. The pointer storage is labeled by the value of the next bit sequence. A pointer to the allocated memory is stored in the pointer storage on the previous level that was labeled by the binary value of the current bit sequence. For the last bit sequence, memory for storing Bloom filters is allocated on the last level. A pointer to the allocated memory is stored in the pointer storage on the second-to-last level that was labeled by the value of the last bit sequence. The Bloom filter is stored in the allocated memory.